TW201308198A - Optimization method for audio playback system - Google Patents

Abstract

A software product for optimizing sound reproduction by an audio system is disclosed. In one embodiment, the software includes an equalization engine for independently adjusting characteristics of an audio signal for each of a plurality of frequency bands. The software then passes the adjusted signal to a dynamics engine having independently adjustable attack and release thresholds and attack and release rate settings to enforce a maximum excursion limit of the speaker driver knowing the voltage-to-excursion relationship for the speaker driver. The software then passes the audio signal to a bass enhancement engine configured to boost all bass frequencies below a bass roll-off frequency of the speaker driver. The boosted signal is passed to a dedicated dynamics engine for the boosted bass frequencies, the dynamics engine again having independently adjustable attack and release thresholds and attack and release rate settings to enforce a maximum excursion limit of the speaker driver.

Description

Optimized method for audio playback system

The present application is generally directed to the optimization of audio output from a variety of audio playback devices, and in particular to software-based solutions for optimizing audio output on an audio playback device.

This International Application claims priority to U.S. Patent Application Serial No. 61/ 501,116, filed on June 24, 2011, which is entitled Incorporated in this article

One of the objectives of any audio playback system is to copy the input audio signal to the listener without the need for a false signal while achieving playback at a high output level. Speaker drivers, speaker cabinets, speaker placement in a listening environment, and the listening environment themselves all affect a listener's experience. Many solutions are known to compensate or otherwise accommodate such variables. However, none of these conventional solutions considers the physical deviation limits of the speaker driver and the listening environment for speaker cabinets, speaker placement, and speaker driver positioning. In addition, conventional solutions only monitor, process, and/or adjust a portion of the audio spectrum rather than monitoring and processing the input frequency as a whole, and the frequency of processing and adjustment typically results in negative results for other unprocessed frequencies, resulting in undesired and Frequent audio news.

Music typically has large voltage spikes that require a compressor/limiter (which acts as a dynamic volume control) and one of the amplifiers to properly match. When there is no compressor/limiter, as the volume of the music is turned up, the amplifier does not The output from the amplifier can continue to be chopped when the input signal is reproduced at the desired output volume (i.e., where the output is independent of the input), or the voltage can exceed the safety limits of the speaker driver. At that time, the signal can introduce significant, undesired distortion into the output signal. On the other hand, a properly designed compressor/limiter can avoid amplifier cutoff and excessive speaker driver deviation by dynamically adjusting the volume down when the input voltage reaches a predetermined threshold setting. However, the compressor/limiter can typically form a false signal, such as gain riding, where, for example, one of the shocks from, for example, the bass drum, the burst bass transient reaches a threshold setting. And the volume of the vocal frequency is dynamically reduced inadvertently when the compressor/limiter function is started.

One of the challenging aspects of the audio playback system delivers a steady state audio signal that matches a target response and a transient audio signal without ringing or other unnatural transients. In the case of a laptop computer with one or more relatively small speaker drivers (i.e., frequency converters), a handheld MP3 player, a mobile phone, and the like, the amplifiers in such systems are typically also relatively small. Due to the relatively low power delivered to the speaker driver, the speaker driver is relatively safe when receiving damaging transient signals. Thus, a relatively large amplitude transient signal can be safely transmitted to a speaker driver in such devices with less compression, since the damaging effects are minimal in such applications. However, in a device such as this, one of the processes known as "digital chopping" occurs when the signal requirements exceed the capabilities of the electronic device that replicated it. If the signal is chopped in this way, the listener will almost certainly hear a poor degradation of the signal.

In contrast, at the other end of the spectrum, driven by a 300 watt amplifier One type of floor-standing stereo speaker driver can result in a significant large deviation of the speaker driver, potentially causing damage to the driver. Transient signals in this situation exacerbate the possibility of damage. As a result, larger transient signals cannot be transmitted to the speaker drivers in such applications, as this can damage the speaker drivers.

In many audio playback systems, the volume level of some bass frequencies is increased to compensate for low volume levels, as well as to compensate for limitations of speaker drivers and ambient acoustic devices, among others. However, conventional bass boost techniques are limited to very low values to prevent premature depletion of driver or amplifier limits, and thus excessive distortion or damage to components. Alternatively, the conventional bass boosting system employing a limiter in conjunction with the boost produces an audio "gain curve" false signal as a result of the relatively small frequency range that is typically boosted, resulting in wideband attenuation of the signal during operation of the limiter. Finally, some types of bass enhancement schemes use psychoacoustic "missing fundamental" techniques that add harmonics to the system to give the illusion that the speaker system is replicating the bass (which is beyond the capabilities of the speaker system). However, this typically produces significant and unwanted artifacts such as distortion, ringing, and other non-linear effects.

Another problem encountered is that a conventional limiter only knows one of the frequency independent voltage thresholds. In contrast, the safe voltage limit of the speaker is strongly dependent on the frequency. For example, the deviation of one of the speakers below or above the speaker of the speaker is significantly different, and thus the amplifier output voltage that allows it to safely drive the speaker is correspondingly different. A conventional limiter does not protect the speaker driver below 埠 tuning because it does not sacrifice at higher frequencies There is no frequency dependence in the case of a large number of output potentials. In addition, a conventional limiter is a wide band because it limits all frequencies. A transient bass signal that exceeds the threshold setting of the compressor/limiter causes the volume to drop to other frequency ranges, adversely affecting the listener's experience. For example, one of the trigger limiter bass drum transients also reduces, for example, the volume of the vocals. Another problem that arises during the use of conventional limiters is filter shifting. High-pass filtering is typically used to protect loudspeakers from extra-frequency signals - especially those whose frequency is lower than the system's replicable frequencies. This keeps the driver off low and prevents the amplifier from wasting power in areas that do not produce usable output. However, since a conventional limiter operates in a frequency independent manner, the value of the voltage below the threshold is allowed to increase until it reaches the threshold, regardless of upstream filtering. In the case of a high pass filter, for example, this has the effect of reducing the frequency of the active high pass filter, thus allowing for higher than desired driver bias. This limiter based frequency shift forces the designer to use one of a combination of lower gain, lower threshold, and higher high pass frequency filter values to protect the system from distortion and damage.

In addition, the bass boosting method utilizing the harmonic concept not only ignores the capabilities of the speaker driver, but also adds distortion to a signal, and in either case is not part of the frequency of the source audio material. Therefore, the listener can hear the need for false signals due to the addition of harmonic frequencies added to the signal by such methods.

In the case of a laptop speaker driver or other frequency converter design having the inherent ability to replicate one of the low frequency signals, the frequency flange may occur below the resonant frequency, such as, for example, below 200 Hz. For example, if Sending a 50 Hz signal to one of the speaker drives of this type will cause the speaker driver to be damaged or excessively distorted due to its physical inability to move away from the drive by a significant amount of air. In such situations, a high pass filter is typically employed to filter out low frequencies, such as frequencies below the resonant frequency. The result is safe for tone sound quality.

Therefore, considering the speaker driver speaker and the intended listening environment, there is a need to duplicate the audio input signal such that the output audio signal results in a maximum amount of safety deviation for one of the intended speaker drivers.

The invention discloses a computer program product stored on a computer readable medium, wherein the computer program product comprises computer executable code instructions executable by a computer processor to optimize sound reproduction of an audio system. The computer executable code instructions include: a first code command for adjusting characteristics of a plurality of frequency bands corresponding to an audio signal; and a second code command for reducing processing by the first code instructions More than one first user can adjust one of the threshold audio signal voltages to force one of the speaker drivers to expect a maximum amount of deviation; and a third code command for improving processing by the second code instructions Lower than about the bass response of the audio signal of the bass resonance frequency of one of the speaker drivers of the audio system, the third code instructions including a fourth code command for reducing the processing by the third code command More than one second user can adjust the voltage of the threshold audio signal to force one of the speaker drivers to expect the maximum amount of deviation.

The first code instructions are configurable to process the audio signal through a plurality of second order filters corresponding to respective frequency bands adjusted by the user for the characteristics. The characteristics corresponding to the plurality of frequency bands may include at least one of a gain, a center frequency of each of the plurality of frequency bands, and a quality factor. The gain, the center frequency, and the quality factor can each be independently adjustable by a user.

The gain can be adjusted continuously or discretely from about -12 dB to about 12 dB. The center frequency can be continuously or discretely adjusted from about 20 Hz to about 20 kHz. The quality factor can be adjusted continuously or discretely from about 0.1 to about 4.0.

The second code command can be configured to process the audio signal according to an independently adjustable and user definable setting, the independently adjustable and user definable settings including an attack rate, a compression reduction At least one of a release rate, a compression start threshold, and a compression reduction threshold. The first user definable threshold can be continuously or discretely adjusted from about 0 dB to about -12 dB.

The third code command can be configured to process the audio signal according to an independently adjustable and user definable setting, the independently adjustable and user definable settings including a bass compression start rate, a bass compression reduction rate At least one of a bass compression start threshold and a bass compression reduction threshold. The second user definable threshold can be continuously or discretely adjusted from about 0 dB to about -12 dB.

In another embodiment, a system for optimizing sound reproduction of an audio system is disclosed, the system comprising: one or more processors; a memory; a first-class engine stored in the memory, the equalization engine including a first code instruction for causing the one or more processors to adjust characteristics of a plurality of frequency bands corresponding to an audio signal; a dynamic engine that is stored in the memory, the dynamic engine including audio to cause the one or more processors to dynamically reduce more than a first user definable threshold processed by the equalizing engine a voltage of one of the signals to enforce a second deviation of the maximum expected amount of the speaker driver; and a bass enhancement engine stored in the memory, the bass enhancement engine including a third code command, etc. Elevating the one or more processors by a bass response of the audio signal processed by the dynamic engine below a bass resonance frequency of one of the speaker drivers of the audio system, and a fourth code command to cause the One or more processors reduce a voltage of the audio signal processed by the bass boost engine by more than a second user definable threshold to force one of the speaker drivers to expect The large departure.

The first code instructions are configurable to process the audio signal through a plurality of second order filters corresponding to respective channels for characteristic adjustment. The characteristics corresponding to the plurality of frequency bands may include at least one of a gain, a center frequency of each of the plurality of frequency bands, and a quality factor. The gain, the center frequency, and the quality factor can each be independently adjusted by a user of.

The dynamic engine may include independently adjustable settings corresponding to a group consisting of: a compression start rate, a compression reduction rate, a delay period, a compression ratio, a threshold, and a compression reduction. Limit or a look-ahead. The bass enhancement engine may include independently adjustable settings corresponding to a group consisting of: a bass boost amount, a compression start rate, a compression reduction rate, a delay period, a compression ratio, and a threshold Value, a compression reduction threshold, a look-ahead, a high pass filter setting, or a soft cutoff setting.

In another embodiment, a method for optimizing sound reproduction of an audio system is disclosed, the method comprising: providing a computer readable medium encoded by a first computer program for independently adjusting a corresponding one Characterizing a plurality of frequency bands of the audio signal; providing a computer readable medium encoded by a second computer program for dynamically reducing a first user readable compression threshold processed by the first computer program a voltage of one of the value of the audio signal to force a maximum deviation of one of the speaker drivers; providing a computer readable medium encoded by a third computer program for the voltage of the audio signal processed by the second computer program to fall Dynamically stopping the voltage reduction when a first user can adjust the compression reduction threshold; providing a computer readable medium encoded by a fourth computer program for boosting a speaker driver that is lower than approximately one of the audio systems One of the bass resonance frequencies of the bass signal rate; Providing a computer readable medium encoded by a fifth computer program for dynamically reducing a voltage of an audio signal processed by a fourth computer program that exceeds a second user adjustable compression threshold to enforce the a maximum deviation of one of the speaker drivers; and providing a computer readable medium encoded by a sixth computer program for the voltage of the audio signal processed by the fifth computer program to fall below a second user adjustable compression This voltage reduction is dynamically stopped when the threshold is restored to return the voltage to a boosted state.

The characteristics corresponding to the plurality of frequency bands may include at least one of a gain, a center frequency of each of the plurality of frequency bands, and a quality factor. The method can further include providing a computer readable medium encoded by a seventh computer program for immediately intercepting a voltage of the audio signal processed by the sixth computer program that exceeds a user adjustable soft cutoff threshold The maximum amount of deviation of one of the speaker drivers is further forced.

The invention discloses a computer program product stored on a computer readable medium, the computer program product having computer executable code instructions executable by a computer processor to enhance the bass response of an audio system, the computer executable code instructions The method includes: a first code command, which is used to boost a voltage corresponding to a low frequency of an audio signal lower than a selected frequency; and a second code command, etc., for reducing the first code by the first code The command boosts the voltage of the audio signal that exceeds a user-adjustable threshold, and the second code command is configured to force one of the speaker drivers to independently deviate from the frequency.

The selected frequency may correspond substantially to one of the bass resonance frequencies of one of the speaker enclosures associated with the speaker driver. The computer program can further include a third code command, the third code command including a high pass filter for processing the audio signal prior to processing the audio signal by the second code command. The computer program product can further include a fourth code command for recombining the reduced audio signal with an audio signal above the selected frequency. The computer program product can further include a fifth code command for the soft cut wave recombined audio signal. The computer program product can further include a sixth code command for delaying an audio signal that is higher than the selected frequency. The compressor can include separate compression initiation and compression reduction thresholds.

In another embodiment, a computer program product stored on a computer readable medium having computer executable code instructions executable by a computer processor to enhance bass response of an audio system is disclosed. The computer executable code instructions include: a first code command, which is used to determine a low bit rate of an audio signal to be boosted below a selected frequency; and a second code command, which is used to boost the corresponding low frequency signal a voltage of one of the audio signals; and a third code command, the compressor including a voltage for reducing the voltage of the audio signal, the third code instructions configured to force a frequency of a speaker driver Independent deviation.

The third code instructions are configurable to process the audio signal according to an independently adjustable and user definable setting, the independently adjustable and user definable settings comprising a group consisting of At least one of them: A compression initiation rate, a compression reduction rate, a compression reduction delay, a compression ratio, an adjustable frequency bypass, a compression initiation threshold, a compression reduction threshold, or a look-ahead. The computer program product can further include fourth code instructions including a frequency dependent limiter for defining one of the voltages of the audio signal based on a frequency dependent threshold for forming a zero filter frequency shift. The first code instructions may include a high pass filter and a low pass filter for establishing one of the low frequency ranges to be boosted below the selected frequency.

In another embodiment, a computer program product stored on a computer readable medium having computer executable code instructions executable by a computer processor to enhance response from one of the audio systems is disclosed The computer executable code instructions include: a first code command including a compressor for reducing a voltage of an audio signal, the first code command being configured to force a frequency independent offset of a speaker driver The first code instructions are configured to process the audio signal according to a user definable setting comprising one of: a compression start rate, a compression reduction rate, a compression reduction delay, a frequency bypass, A compression start threshold and a preview.

The setting can include at least one of a compression ratio and a compression reduction threshold. The computer program product can further include a second code command, the second code command including a low pass filter for filtering the audio signal prior to processing the audio signal by the first code command. The low pass filter can be a first order low pass filter. The computer program product may further include a third code instruction. The third code instructions are for soft chopping the voltage of the audio signal that is processed by the first code command by more than an adjustable soft chop threshold to further force a maximum amount of deviation of the speaker driver. The computer program product may additionally include a fourth code command, the fourth code command including filtering the audio signal after processing the audio signal by the first code command for forcing a frequency dependent threshold A high pass filter. The high pass filter can be a second order or higher order high pass filter.

In another embodiment, a method for optimizing sound reproduction of an audio system is disclosed, the method comprising: providing a computer readable medium encoded by a first computer program for a bass of an audio signal For rate filtering, the first computer program includes a low pass filter configured to transmit a low bit rate below an adjustable low pass filter setting and configured to transmit a higher than an adjustable high pass filter setting a high pass filter of the low frequency filter, the low pass filter setting comprising a frequency higher than one of the high pass filter settings; providing a computer readable medium encoded by a second computer program for a bass response of the audio signal transmitted by the first computer program; and providing a computer readable medium encoded by a third computer program for dynamically reducing the excess of an adjustable threshold transmitted by the second computer program A voltage of one of the audio signals to force a maximum amount of safety deviation from one of the speaker drivers associated with the audio system.

The low pass filter can be a fourth order low pass filter. Low pass filter It can be set to approximately one of the resonant frequencies of the speaker driver. The high pass filter can be a second order high pass filter. The method can further include providing a computer readable medium encoded by a fourth computer program for dynamically stopping when a voltage of the audio signal processed by the third computer program falls below an adjustable compression reduction threshold This voltage is reduced to return the voltage to a boosted state. The method can further include providing a computer readable medium encoded by a fifth computer program for soft chopping the voltage of the audio signal processed by the fourth computer program that exceeds an adjustable soft cutoff threshold to further Force one of the speaker drivers to have the maximum amount of deviation.

In another aspect, a non-transitory computer readable medium comprising computer readable instructions for optimizing an audio response from an audio playback system is provided. The non-transitory computer readable instructions, when executed on a computer, cause the computer to perform the method steps described herein.

A good understanding of the objects, advantages, features, properties and relationships of the present invention will be obtained from the following detailed description and the accompanying drawings.

Although the figures and the following disclosures illustrate one or more embodiments of an optimization method for an audio playback system, those skilled in the art will appreciate that the teachings of the present invention are not limited to being combined with only an audio playback system. Use, but will be aware that the teachings of the following disclosures may also apply to other aspects of sound recording.

An embodiment of the present invention is directed to enabling a designer and manufacturer of an audio playback system to be aware of various characteristics of a speaker system, speaker placement The software tool for trimming the output audio signal while listening to the environment. One aspect of the software tool incorporates knowledge of the relationship between the deviation of the speaker driver and the voltage output for a given playback system, speaker driver, speaker cabinet, speaker placement, and listening environment.

One embodiment of the present invention includes three parts that work together toward maximizing the audio performance of an audio playback system, including a playback system incorporating a loudspeaker or a frequency converter. The three parts are a first-class engine, a dynamic engine, and a bass boost engine. In one embodiment, an audio input signal is first processed by an equalization engine and then processed by a dynamic engine and then processed by a bass boost engine to optimize the output signal for delivery to one or more speaker drivers. In other embodiments, the signal can be processed in either order.

Once a speaker driver and speaker are known, an output voltage pair deviation relationship can be determined to obtain a safe voltage limit that the speaker system can handle with frequency. These voltage limits will have a strong frequency dependence such that safety limits below resonance will generally be significantly lower than their safety limits above the resonance. Once the safe output voltage is known, a compressor/limiter can be programmed to independently enforce the limits of the two regions.

Equalization engine

The function of the equalization engine overcomes and corrects the deficiencies in the sound reproduction chain to produce a desired response at the listener's ear. For example, the first-class engine can adjust the output signal to compensate for speaker driver limitations or to correct for different listening environments. In one embodiment, the first-class engine includes an adjustable high-pass filter and a low-pass filter, and a fully parametric filter for providing maximum flexibility, accuracy, and fidelity to enable a playback device manufacturer (For example) trimming the output signal for a given speaker driver and listening environment. A high pass filter blocks relatively low frequencies and allows all frequencies above the high pass filter set point frequency to pass. A low pass filter blocks relatively high frequencies and allows all frequencies below the low pass filter set point to pass.

A parametric filter is one in which the quality factor (Q) of the frequency, the gain, and the shape describing the band pass filter can be adjusted independently of each other. The Q system is defined to be equal to the center frequency divided by the bandwidth, where the center frequency is defined as the frequency at the center of the band and it typically represents the peak of the frequency response curve. The bandwidth is defined as the difference between the frequency above the frequency response curve and the lower frequency in the case where the gain has dropped to 0.707 of the intermediate band gain (i.e., the voltage gain at the center frequency). Therefore, a relatively low Q means a relatively wide bandwidth, and a relatively high Q means a relatively narrow bandwidth. Thus, parametric equalization of an audio signal provides a frequency response curve ranging from a relatively wide bandwidth to a relatively narrow bandwidth.

Parametric equalization is a powerful tool for adjusting the input audio signal so that the output signal results match the target frequency response of all audio frequencies. In principle, this is achieved by knowing the characteristics of the speaker driver, the speaker cabinet, the speaker placement and listening environment, and, for example, the effect of an increase or decrease in gain adjustment at the position of the listener relative to the speaker driver. of.

Dynamic engine

In particular, loud sounds from small devices such as iPods, mobile phones, laptops, and the like impose heavy loads on the speaker drivers and electronics of the playback system of the device. In one embodiment, including a pressure One of the reducer/limiter or dynamic volume control dynamic engine ensures that these requirements are still within the safety limits of both the compressor/limiter and the dynamic volume control, ensuring purity and no even at very high output levels Distortion output. This is done by forcing a limit on the output voltage of the audio signal. In particular, a compressor/limiter dynamically reduces the voltage of the audio signal when the audio signal will exceed system capability, allowing it to play significantly louder than would otherwise be possible without distortion. Thus, in this context, a compressor/limiter prevents signal chopping by setting a compressor threshold, which is set to achieve a target output level that is substantially lower than the target output level. The point at which the output signal can be chopped. In one embodiment, the threshold is set to be approximately 1 to 2 dB lower than the point at which the output signal is expected to be chopped.

A compressor/limiter sets a compression ratio that is defined as the ratio of the input signal (dB) to the output signal (dB) when the signal is above the defined threshold. As the compression ratio tends to become higher, for example with a slope of 20 to 1, the compressor/limiter will act as a limiter due to the nearly horizontal slope of the curve. That is, a large change in the input signal produces a very small output change. As the compression ratio tends to become lower, for example with a slope of 2 to 1, the compressor/limiter works finer and acts as a compressor with a large change in the output as the input changes.

However, the use of a compressor/limiter creates a false message resulting from compressing the out-of-bounds frequency range without compressing the unaffected frequency. For example, if a steady state signal is close to the threshold setting, a sinusoidal audio signal may exceed the threshold and trigger the compressor/limiter, but occurs after 2 to 3 ms. One of the samples may have been shown to be below the threshold setting. Since the system attempts to trigger on the threshold and then removes the compressor (compression reduction) when compression is no longer needed, this results in an oscillation of the output volume for the triggered frequency. In addition, since a conventional limiter does not have frequency dependence, its operation can result in unwanted high pass filters and low pass filter frequency shifts. For example, as shown in FIG. 1, a high pass filter together with a conventional limiter causes a frequency shift of, for example, 100 Hz to 50 Hz due to the limiter. In contrast, as shown in FIG. 2, processing an audio signal under the same conditions through a high pass filter without causing any limiter to cause any frequency shift of the output signal.

Although many compressor/limiter solutions are known to exist, the compressor/limiter employed in one embodiment of the present invention is specifically designed for use in an audio playback system in which the output signal can be made when the compressor threshold is met. Compressing the start slowly enough to allow for a non-damaging transient signal while compressing the reduction fast enough to make the listener audibly clear and audible, processing only the portions of the signal that require the compressor/limiter and When done, it produces about zero distortion. To achieve this, the compressor/limiter in one embodiment of the invention includes separate compression initiation and compression reduction settings, and compression reduction delay, frequency bypass, and look-ahead functions. Additionally, filtering can be employed both before and after compression to enable a frequency dependent threshold and zero filter frequency shift.

In particular, once an audio input signal reaches the compressor/limiter threshold setting, one of the compressor/limiter compression start settings of the dynamic engine can be programmed (which can be dB/ms or dB/sample) Unit expression) with delay Any immediate action of the compressor/limiter reduces the output voltage of the input signal based on the compression start setting. In this way, the non-damaging transient signal (which can briefly exceed the compressor threshold setting) can be passed without compression, thus preventing any such volume caused by the triggering and subsequent release of the compressor/limiter oscillation.

Therefore, a separate compression start setting determines how the compressor/limiter will act on one of the input signals beyond the threshold setting. The compressor/limiter will immediately act on a signal that exceeds the threshold and continues to exceed one of the thresholds longer than the compression start setting to reduce the output voltage and thus reduce the output volume sent to the speaker driver.

In contrast, a single compression reduction setting determines how quickly the compressor/limiter will stop acting on the input signal after an input signal falls below the trigger threshold setting. In particular, once the compressed audio input signal falls below the compressor/limiter threshold setting, one of the dynamic engine compressor/limiter compression reduction settings can be programmed (which can be dB/ms or The dB/sample is expressed in units of any immediate action of the delay compressor/limiter to stop acting on the signal according to the compression reduction setting. In this way, the input signal can continue to be compressed (ie, the output voltage is reduced) below the compressor/limiter threshold until the risk of transient signal spikes and thus the risk of damage to the speaker driver gradually disappears to almost no The extent of attention. This also helps by preventing excessive two-state switching between compression initiation and compression reduction.

A further option to the dynamic engine is programmed to trigger one or both when the compressor/limiter is triggered and/or when the compressor/limiter is compressed and restored. One of the compression reduction delays occurs. However, one of the delay characteristics including a delay setting is based on a selected time increment rather than an actual signal, which can form a false signal in the output signal during use. This compression reduction delay is also used to prevent excessive transitions between compression initiation and compression reduction, and thus provides a smoother and invisible compressor response.

An additional option to one of the dynamic engines is a frequency bypass feature such that frequency content below only a specified frequency is processed by the compressor/limiter, and content above the specified frequency is not processed to match, except for sufficient delay Look ahead and ensure the desired signal reconstruction. Very high frequency chopping is neither damaging nor audible, and is unlikely to occur with real world signals, but nevertheless it can trigger a compressor/limiter to reduce gain. The bypass feature prevents such false triggering of the compressor/limiter by constraining only those signals that are related to sound quality or speaker protection. The bypass feature can be implemented using a low pass filter (such as a first order low pass filter) and a high pass filter (such as a first order high pass filter), wherein the low pass filter is set to adjustably Set to the same or approximately the same frequency as the adjustable high-pass filter settings. In this manner, the compressor/limiter can operate at frequencies below the "common set point (or at least low pass filter setting)" and above the common set point (or at least the high pass filter setting). It may be left untreated except for introducing sufficient delay as described above.

Yet another option for the dynamic engine is to programmatically sample one of the digital audio signal samples at a certain time period prior to signal processing by, for example, triggering of the compressor/limiter. By doing so, the dynamic engine can react in advance and, for example, over a longer period of time rather than immediately Smoothing the compression initiation feature of a transient signal that is about to be exceeded, in order to avoid volume audio changes that can be heard by a listener.

In general, the compressor/limiter disclosed herein can be programmed to enable a user to shape the peak output voltage using a range of filtering to match the maximum output of the spectrally matched amplifier across the audible frequency to the maximum speaker driver. The safe voltage results in a high-sound, substantially distortion-free audio output in which the processing of the audio input signal is not apparent to the listener's ear.

Bass boost engine

The bass boost engine's function boosts the bass response or volume across all bass frequencies set below an adjustable low-pass filter without adding harmonics or false alarms. The adjustable low-pass filter settings can be set. At the resonant frequency of the speaker driver where the frequency begins to roll. Knowledge of the actual speaker driver and speaker enclosure will inform a system designer of the trimming frequency of the speaker driver/speaker combination, and thus the combination to be applied to the system based on its low pass filter setting that causes one of the low frequency responses to be rolled.

In one embodiment, the frequency can be passed through a low pass filter (such as a fourth order low pass filter that can be adjustably set to pass frequencies below, for example, the resonant frequency) and predetermined However, a fully adjustable amount (such as about 20 dB) gain is added to all of these bass frequencies. As mentioned above, these frequencies may all be lower than the point at which frequency flanging begins to occur for the speaker driver/speaker speaker combination. A high pass filter (such as a second order high pass filter) may additionally be included to pass the higher than one adjustable high pass filter setting and lower than the adjustable low pass filter setting of the low pass filter In order to establish a frequency range that can be boosted by the bass boost engine Wai. Including the high pass filter may be advantageous in the case where the relatively low frequency is not replicated in a particular speaker driver entity such as a cellular telephone driver or a laptop driver Exclude relatively low frequencies.

In the context where one user chooses not to use the bass boost engine, the second order high pass filter can still be used in conjunction with a compressor/limiter to provide a level independent even during the passage of large gain reductions. High pass filter. To achieve this, the boost or gain of the bass boost engine can be set to zero, with the second-order high-pass filter set at approximately the resonant frequency.

The bass boost engine can further include a bypass circuit for frequencies above the low pass filter setting. For example, a frequency set by the low pass filter higher than the low pass filter can be passed through a high pass filter (such as a fourth order high pass filter), the high pass filter can be adjustably set To the same or approximately the same frequency as the adjustable low-pass filter setting. In this way, the frequency below the common set point (or at least the low pass filter setting) can be boosted by the bass boost engine while the frequency above the common set point (or at least the high pass filter setting) can be transmitted to a bypass circuit For final recombination with the low pass frequencies after boosting by the bass boost engine. An adjustable delay can be introduced to the bypass frequencies (i.e., above the common set point or high pass filter setting) to ensure desired reconstruction of the signal and the frequency set by the hell low pass filter.

Since one of the gains of about 20 dB is relatively high, the resulting signal can cause the amplifier to intercept if the transient output signal exceeds the capability of the amplifier or can exceed the driver's ability to deviate at a high level. To avoid this transient intercept Or excessive deviation, one embodiment of the bass enhancement engine includes one of the types of compressors/limiters discussed above to separately process and/or compress the transmitted bass frequencies below the low pass filter settings to a signal voltage exceeding The degree of the threshold or safe voltage limit of the speaker driver. The deviation is constant or frequency independent below the resonant frequency of the speaker cabinet. Therefore, one of the compressor/limiters that is set to force a voltage threshold setting only over this frequency range has the effect of producing a constant deviation from the driver. As before, the compressor/limiter is forced to be based on one of the known safety deviation limits of the speaker driver when installed in the speaker cabinet.

In principle, the signal output voltage can be correlated with the measured deviation of the speaker driver to provide a voltage-to-offset relationship. By knowing this relationship, the bass boost engine's compressor/limiter threshold setting can be programmed or otherwise set at or just below the maximum safe deviation limit of the speaker driver. One of the voltages is used to protect the speaker driver from deviation-related damage. Alternatively, the threshold setting can be expressed in decibels. In one embodiment, the threshold setting can be set by the user to or below a predetermined safety deviation limit of the speaker driver (such as about 1 dB to about 2 dB lower) Any value that will result in meeting or exceeding this safety deviation limit.

The same goes to the figures, in which the same element symbols refer to the same elements. 3 shows an exemplary embodiment illustrating one of the speaker drivers being frequency independently deviated by a compressor/limiter forcing a frequency dependent threshold. For example, a compressor/limiter threshold 46 can be used It is set to be about 1 dB to about 2 dB lower than the resonant frequency 42, which is shown to be approximately 100 Hz in this example. One of the forced thresholds 46 of the compressor/limiter results in a constant deviation 48, which in this example is shown to be approximately 1.84 mm, and which may be at the maximum safety deviation limit of an exemplary loudspeaker driver or Below this maximum safety deviation limit.

The compressor/limiter of the bass boost engine may include separate compression initiation and compression reduction thresholds that contribute to the out-of-bounds input signals as discussed above. If the input signal does not exceed the threshold setting, the compressor/limiter function of the bass boost engine does not need to act on the signal. However, if the input signal exceeds the threshold and the compressor/limiter is triggered, the compressor/limiter may compress the signal to initiate a decrease in voltage and thus reduce the boosted bass according to a compression start setting. The volume of the signal. If the input signal falls below the threshold setting, the compressor/limiter can stop acting on the signal, thereby allowing the voltage to return to an uncompressed voltage and thus rising according to the compression reduction setting. These have raised the volume of the bass signal.

In one embodiment, the compressor/limiter acts on all frequencies below the low pass filter setting if the input signal exceeds a threshold setting. In another embodiment, the compressor/limiter can act on certain boosted low or low frequency ranges if the input signal exceeds the threshold setting. For example, as described above, a high pass filter (such as a second order high pass filter) and a low pass filter (such as a fourth order low pass filter) can be used in combination with each other to establish the signal. Exceeding this threshold setting can be boosted and then compressed to a range of bass frequencies.

In one embodiment, the bass boost engine may include a soft cutoff function downstream of the compressor/limiter of the bass boost engine to instantly compress the start and compression to restore a particularly damaging input signal. The soft chopping function is used as one of the compressor/limiter backups to immediately intercept the unsafe input signal through one of the compressor/limiter. The soft chopping function may facilitate the setting of a relatively high bass boost by a user of the bass booster engine due to the layering of the speaker driver protection, for example approximately 20 dB or more, while enabling the use of the original A slower compression start and a compression reduction rate will be permitted.

With the teachings of the present invention, there is now a maximum deviation bass boosting strategy that allows the speaker driver to make a full, pure bass that reaches the limits of the speaker driver without incurring audio artifacts.

Turning now to Figures 4 through 6, an exemplary user interface 10 is illustrated that illustrates an embodiment of the present invention to maximize spanning, for example, mobile devices, laptops And audio replication and playback performance for standalone speaker applications. 4 shows, for example, an example equalization engine user interface 20 for an equalization engine 140 that includes a plurality of user adjustable settings. More specifically, the equalization engine user interface 20 includes a total power on-off switch 22, a prescaler 24, an automatic prescaler 26, a plurality of second order filters 30, and a save/download file. Features.

As with most user-adjustable settings in the user interface 10, the prescaler 24 can use a continuous sliding axis adjustment or setting, or another selection system that can be manually selected by selecting one of the prescalers 24. Button or by one The prescaler 24 is selected from the options in the drop down list to adjust or set. Prescaler 24 can range from about 0 dB to about -20 dB. The prescaler 24 is used to prevent digital truncation by reducing the gain of the signal (which would otherwise exceed the digital 0 dB) before the high signal is boosted by the equalization engine 140. The prescaler 24 can be toggled between on or off by a user using the automatic prescaler 26 and as desired to select the "on" or "off" position.

The equalization engine user interface 20 of Figure 4 shows five second order filters 30, each of which corresponds to a respective frequency band for user adjustment. Another embodiment may include fewer or more filters to finer or coarsely adjust the signal waveform. In the embodiment of FIG. 4, each second order filter 30 includes fully parametric control for frequency, gain, and Q to independently adjust each of these settings. A user can set the frequency 31 to be from > about 20 Hz to about 20 kHz continuously or in increments of about 1/48 octaves or less. Gain 32 can vary from about -12 dB to about 12 dB continuously or in increments of about 0.5 dB or less. The quality factor (Q) 33 can vary from about 0.1 to about 4.0 continuously or in increments of about 0.05 or less. As shown in FIG. 4, frequency 31, gain 32, and Q 33 can each be adjusted or set using a continuous sliding axis, or another selection system can be selected by manually selecting one of the buttons for implementing such settings or by Select from the options in the pull list to adjust or set. The second order filter 30 may further include a switch 35 as shown in FIG. 4 for two-state switching and display of filter types including: peak filtering, dip filtering, bypass filtering, adjustable Q high-pass filtering, adjustable Q low-pass filtering, bass filtering, notch filtering, bandpass filtering, all-pass filtering, and treble filtering Waves, whose effects are shown graphically in Figure 38.

Turning now to Figure 5, an exemplary dynamic engine user interface 50 for dynamic engine 150 is shown, including for compression start 52, compression reduction 54, delay 56, compression ratio 58, frequency limit (F limit). 60, threshold 62, compression reduction threshold 64 and (as appropriate) pre-view 66 independent adjustable settings. The dynamic engine user interface 50 further includes an on/off switch 72 for engaging or disengaging the dynamic engine 150 for providing supplemental gain such that the peak after compression is close to 0 dB, then the crossover setting 68, automatic postscaling The switch 70 and the cue indicator light 74 are turned on/off and a reset button 76 for resetting the dynamic engine user interface 50 when the signal is chopped. The chop indicator light 74 provides that at least one sample of the signal exceeds the digit 0 dB and is thus visually indicated by one of the cuts. In addition, one of the signal level and the peak signal level retention display can be displayed in the dynamic engine user interface 50. When a user selects the reset button 76, the cue indicator light 74 is turned off and the peak signal level is held and the detector is reset to zero.

In the embodiment of FIG. 5, the compression start 52 can vary from about 0 dB/ms to about 10 dB/ms continuously or in increments of about 0.1 dB/ms or less, with a typical value of about 0.4 dB. /ms. The compression reduction 54 can vary from about 0 dB/ms to about 10 dB/ms continuously or in increments of about 0.01 dB/ms or less, with a typical value being about 0.04 dB/ms. The delay 56 can vary from about 0 ms to about 100 ms continuously or in increments of about 1 ms, with a typical value being about 10 ms. The threshold can vary from about 0 dB to about -12 dB continuously or in increments of about 1 dB or less. The compression ratio 58 represents the input to output ratio for the signal portion above the threshold and may be (continuously or in increments of about 1) 1:1 to about 20:1. Frequency (F) limit 60 represents a frequency limit above which dynamic engine 150 will not process/bypass signals based on complementary high pass/low pass filter settings at the other frequencies. The compression reduction threshold 64 provides a single threshold setting for compressor/limiter compression reduction and can vary from about 0 dB to about -12 dB continuously or in increments of about 1 dB or less. . The look-ahead 66 can vary from about 0 ms to about 10 ms continuously or in increments of about 0.1 ms. As before, each of these settings can be independently adjusted by a continuous sliding axis, by selecting a button for manually entering a respective setting, or by selecting an appropriate setting from a pull-down list.

Turning now to Figure 6, an example bass boost engine user interface 80 of the bass boost engine 160 is shown, which includes frequency 82, boost 84, threshold 86, compression reduction threshold 88, look-ahead 90, bass high pass. Filter 92, compression start 94, compression reduction 96, delay 98, compression ratio 100, soft chopping 102, and soft chop main on/off switch 104.

A user can independently adjust frequency 82 from about 20 Hz to about 1000 Hz continuously or in increments of about 1/48 octaves or less. For maximum performance, the frequency 82 can be set at or near the resonant frequency of the speaker driver/speaker speaker system where the bass starts to roll. As described above, the bass boost engine processes all frequencies below this frequency set point based on the value of the boost setting 84. The boost setting 84 can vary from about 0 dB to about 40 dB continuously or in increments of about 1 dB or less.

Threshold 86, compression reduction threshold 88, look-ahead 90, compression start 94, compression reduction 96, delay 98, and compression ratio 100 are each adjustable and are the same as described above for dynamic engine user interface 50. The way it works. low The pitch pass filter 92 is operative to cause the bass boost engine 160 to filter out one of any of the frequencies below the indicated set point. The bass high pass filter 92 can also be used to prevent frequency shifting without meshing bass boost. Soft chopping 102 instantly compresses the start and/or compression to restore a particular damaging input signal, and thus reduces the volume of the output signal based on the soft chopping settings, thus preventing any digital truncation. In one embodiment, the soft chopping 102 is set to a point just below 0 dB to help ensure that the soft chopping function is triggered only when absolutely necessary.

Turning now to Figure 7, a system 125 is shown that shows an exemplary operational sequence for processing an input audio signal 130. The input audio signal 130 enters an equalization engine 140 that operates to balance or correct for any deficiency in the sound reproduction chain to provide a target frequency response at the listener's ear. Once the signal has been adjusted according to the algorithms and settings programmed in the equalization engine 140, that is, the signal 130 is subsequently transmitted to the dynamic engine 150, the dynamic engine 150 can compress over, for example, a threshold 62 up to ( For example, any transient of the F limit value 60. From there, signal 130 is transmitted to bass boost engine 160 to boost bass response across all bass frequencies below, for example, the setting of frequency 82. As shown in more detail in FIG. 8, depending on the setting of frequency 82, the signal entering bass boost engine 160 first passes through low pass filter 162, which may be a fourth order low pass filter. The compressor/limiter 164 can then be used to compress more than, for example, the threshold 86, according to any of the thresholds 86 and other compression initiation, compression reduction, delay, etc. settings shown in FIG. State signal. After exiting the bass boost engine 160, the output signal will be output by the playback system. 170 is amplified and delivered to the speaker driver.

In one embodiment, system 125 provides the ability to allow a user to load at least two different saved settings groups (including all signal processing for each group) to allow the user to instantly switch between them. . In this way, a user can quickly compare the output signals processed by each, and in addition, the system 125 can interleave all signal processing settings simultaneously or over time or phase to the left and right channels, to One channel or another channel.

Turning now to Figures 9 through 11, an exemplary embodiment of one embodiment of the present invention is shown. As shown in FIG. 9, system 200 includes a prescaler engine 202, an equalization engine 210, a dynamic engine 250, a bass boost engine 300, and a postscaling engine 323. An input signal is first received and processed by the prescaler engine 202, and then output is received and processed by the equalization engine 210 to correct for insufficient in the voice copy chain to obtain a desired response at the listener's ear, which is then received by the dynamic engine 250. And processing the output to ensure that the audio signal is still within the desired limits of the speaker driver to ensure a distortion-free output even at very high output levels, and then the bass boost engine 300 receives and processes the output to span a broad bass spectrum. To boost the bass response while maintaining the desired limit of the speaker driver while ensuring a distortion free audio output, and then the output is received and processed by the post-scaling engine 323. In other embodiments, the processing of the signals can be in any order.

The prescaler engine 202 is configured to reduce the gain of the input audio signal (if needed) prior to equalization by the equalization engine 210, thereby allowing sufficient digital headspace such that any peaks will not exceed the digital 0 dB. Post-frequency engine 323 is configured to increase the gain of the output audio signal (if needed) to supplement any gain reduction caused by prescaler engine 202 and, for example, compressor 258, so that the system output does not exceed the speaker driver It is as high as possible from the limit.

The parametric filtering engine 211 transmits signal filtering from one of the prescaler engines 202 to the equalization engine 210 using, for example, user predetermined parameter settings for frequency 220, gain 221, and quality factor (Q) 222. Such settings may be selected or determined by a user using, for example, the equalization engine user interface 20 described above.

Turning to Figure 10, a detailed block diagram of an exemplary equalization engine 210 is shown. As shown, the equalization engine 210 includes an input block 208 for inputting an audio signal 209, a parametric filtering engine 211, and an output block 232 for the audio signal 233 after processing by the parametric filtering engine 211. The parametric filtering engine 211 includes a filtering engine 213 and a filter setting 219 corresponding to each of a plurality of frequency bands that a user desires to filter. In the embodiment of FIG. 10, for example, a total of five frequency bands for continuous operation are shown, but any integer less than or greater than five is possible, up to the limit of available processing power of the computer processing unit and available memory. . For many applications, five channels can be a reasonable compromise between the resource requirements on the host system and the full response from the system. Alternatively, a space optimized mobile phone implementation (for example) can utilize only three frequency bands to achieve target performance, while a high power PC implementation can utilize seven frequency bands. In another embodiment, the bands may be processed in parallel by the equalization engine 210 for the multiplex system, where the input will be stereo, but the output may be 4 Or more than 4 channels, such as one channel for each of the left low frequency speaker, the left high frequency speaker, the right low frequency speaker, the right high frequency speaker, and the like.

The filtering engine 213 includes a bypass engine 214, an adjustable Q high-pass engine 215, an adjustable Q low-pass engine 216, a peak processing engine 217, and a bass class processing engine 218, and a user can select any frequency band selected by the user, Either or none of the above engines are selected for all or none of the bands. The bypass engine 214 bypasses the filter bank so no signal processing is performed. The adjustable Q high pass engine 215 produces a variable Q second order high pass filter. The adjustable Q low pass engine 216 produces a variable Q second order low pass filter. Peak processing engine 217 produces a peak or valley filter. The bass level processing engine 218 produces a second order adjustable Q bass level filter.

For each frequency band of the parametric filtering engine 211, according to the bypass engine 214, the adjustable Q high pass engine 215, the adjustable Q low pass engine 216, the peak processing engine 217, or the bass class processing engine 218 (whichever one is selected) The user selects the settings and the filtering engine 213 first processes an input audio signal. The signal is then processed using filter settings 219 based on user selectable settings for frequency 220, gain 221, and Q 222.

As shown in FIG. 9, after an audio signal is processed by the equalization engine 210, the signal is then passed to the dynamic engine 250 for processing. The signals transmitted to the dynamic engine 250 may be filtered by a dynamic filtering engine 251 having, for example, a first order high pass filtering engine 253 for transmitting respective high and low frequencies for further processing by the dynamic processing engine 257. And a first order low pass filtering engine 254. Dynamic processing engine 257 can include (For example) delay processing engine 276 and compressor 258 (see also Figure 11). As shown in FIG. 9, delay processing engine 276 processes the frequency to which it is transmitted by first order high pass filtering engine 253, while compressor 258 processes the frequency to which it is transmitted by first order low pass filtering engine 254.

Turning to Figure 11, a detailed block diagram of an example dynamic engine 250 is shown. As shown, the dynamic engine 250 includes an input block 248 for inputting an audio signal 249, a dynamic filtering engine 251, a dynamic processing engine 257, a dynamic integration engine 282, and an output for the audio signal 289 after being processed by the dynamic engine 250. Block 288.

The dynamic filtering engine 251 includes a bypass filtering engine 252 having, for example, a first order high pass filtering engine 253 and a first order low pass filtering engine 254. Although the first order filter may provide a seamless transition between the processed component and the bypass component, a higher order or adjustable order filter may alternatively be utilized. The dynamic processing engine 257 includes a limiter setting block 260, a limiter processing engine 268, a compressor setting block 271, a look-ahead delay engine 275, and a gain reduction engine 279. The look-ahead delay engine 275 includes a delay processing engine 276 that receives the output signals transmitted thereto from the first-order high-pass filter engine 253 and sets them according to a user-specified delay (such as the look-ahead 66 described above). ) to process this signal. The output signal from the delay processing engine 276 is passed to the dynamic integration engine 282 for combining the signal and filtering by the first order low pass filtering engine 254 and by the compressor according to, for example, a user specified frequency limit 60. 258 transmitted signal.

In contrast, the compressor 258 of the dynamic processing engine 257 receives the output signals transmitted thereto from the first order low pass filtering engine 254 and is based on various users. Specify settings to handle this signal to protect the speaker driver from damage while maximizing volume output. For example, as shown in FIG. 11, the limiter setting block 260 of the compressor 258 includes a compression start rate 261, a compression reduction rate 262, a threshold 263, a compression reduction threshold 264, and a compression reduction delay 265. Each can be selected or determined by a user using, for example, the dynamic engine user interface 50 described above. Those skilled in the art will appreciate that alternative embodiments of the limiter setting block 260 can include one or more of such user selectable settings.

The output of the first order low pass filter engine 254 that exceeds the user specified threshold setting 263 will be received by the limiter engine 269 and transmitted to the look-ahead delay engine 275 and the gain reduction engine 279, where the blocks are set according to the limiter, respectively. The user-specified limiter settings of 260 and the user-specified compressor settings of compressor set block 271 are applied by gain reduction processing engine 280 to reduce the gain. As shown in FIG. 11, the output of the first order low pass filtering engine 254 is transmitted as signal 266, which is processed by the look-ahead delay processing engine 277 in accordance with a user-specified setting, such as look-ahead 273. In this manner, the gain calculated by the limiter engine 269 and applied by the gain reduction engine 279 reduces the lead signal 266 by the defined look-ahead time. The gain reduction calculated by the limiter engine 269 according to the compression ratio 278 is applied by the gain reduction processing engine 280 to the filtered and delayed signal.

The output signal from the gain reduction processing engine 280 of the compressor 258 is passed to the reassembly engine 283 of the dynamic integration engine 282 for combining this signal with the filtering by the first order high pass filtering engine 253 and processed by the look-ahead delay engine 275. Signal, which ensures that the processed and unprocessed signals are preferably still timed Aligned. The output of the dynamic integration engine 282 forms an output signal 289 of the output block 288 that forms the input signal to the bass boost engine 300.

A variation of the embodiment of Fig. 11 is shown in Fig. 12. For example, FIG. 12 further includes a threshold shaping engine 285 having a high pass filtering engine 286. The high pass filtering engine 286 can include a second order or higher order high pass filter. By providing a filter after compressor 258, a voltage threshold can be trimmed to match the offset capability of a speaker driver.

Turning again to FIG. 9, the bass boost engine 300 includes a bass filter engine 301, a bass protection engine 305, a bass boost engine 309, a bass compressor engine 313, a bass integration engine 317, and a bass soft cutoff engine 320. As shown, the signal is filtered by a bass filtering engine 301 having, for example, a fourth-order high-pass engine 302 and a fourth-order low-pass engine 303 for transmitting respective high and low frequencies for bass The protection engine 305, the bass boost engine 309, and the bass compressor engine 313 are further processed. The frequency transmitted from the fourth-order high-pass engine 302 is passed to the bass boost engine 309 and processed by the delay processing engine 310 according to a user-specified delay setting, such as the delay 98 described above. The output signal from the fourth-order high-pass engine 302 is not otherwise processed by the bass protection engine 305, the bass boost engine 309, or the bass compressor engine 313, as shown by the bypass blocks 306, 314 of FIG.

In contrast, the bass protection engine 305 of the bass boost engine 300 receives the output signal transmitted thereto from the fourth-order low-pass engine 303 and processes the signal via the second-order high-pass engine 307. The output of the second order high pass engine 307 is then passed to the bass boost engine 309 where the user specified gain 311 is applied to boost the signal. Then pass the boost signal to the bass compressor engine The 313 bass compressor processing engine 315 compresses an out-of-bounds transient signal that exceeds a user-specified threshold setting, such as threshold 86 discussed above, in conjunction with, for example, other user-specified settings. Those skilled in the art will appreciate that the bass compressor processing engine 315 can include many or all of the elements discussed above for the compressor 258 and shown in FIG. 11, but configured as part of the bass boost engine 300. These components will only process the signals transmitted thereto from the bass boost engine 309, i.e., primarily including the low frequency, and only to the extent that the frequencies exceed a user-specified threshold setting. A user interface, such as bass boost user interface 80, can be implemented in conjunction with bass boost engine 300 to provide user selectable input for use by bass boost engine 300. The output from the bass compressor processing engine 315 is passed to a recombination engine 318 of the bass integration engine 317 for combining this signal with the signal filtered by the fourth order high pass engine 302 and processed by the delay processing engine 310.

To further enforce one of the maximum deviation limits of the speaker driver as shown in FIG. 9, the combined signal from the bass integration engine 317 is transmitted to the bass soft cut engine 320 and processed via the bass soft cut processing engine 321. As discussed above, the soft chopping function employed downstream of the bass compressor engine 313 of the bass boost engine 300 can be configured to instantly initiate compression and compression reduction of a particular damaging input signal as a bass compressor engine 313. One of the backups succeeds in intercepting the unsafe input signal through one of the bass compressor processing engines 315 without introducing audio distortion.

The bass soft cut engine 320 can be configured by transmitting the signal to the bass soft cut engine 320 after the signal is processed by the bass compressor engine 313 To address the potentially damaging transient signal (which passes through the bass compressor processing engine 315 and the compressor 258 of the dynamic engine 250). The bass soft cutoff engine 320 is more aggressive than the bass compressor engine 313 but less aggressive than a pure limiter and can be configured by a user to process signals according to user specifications.

As shown in FIG. 9, the signal processed by the bass soft chopping processing engine 321 is then passed to the postscaling engine 323 and then the frequency dividing processing engine 324.

Turning to FIG. 13, an exemplary steady state signal response for one of the signals processed by an example dynamic engine 250 or an example bass boost engine 300 is shown. A representative output signal is shown plotted against a representative input signal for a threshold value of -6 dB below and above a threshold setting of 3 and a compression ratio of 4:1. Below threshold setting 330, curve 332 has a 1:1 linear slope that reflects the fact that the compressor is not triggered and the output signal is the same as the input signal. The compressor reduces the voltage of the signal based on the slope of the compression ratio for an input signal that exceeds the -6 dB value of the threshold setting 330; in this example, at a rate of 4:1, as shown by compressor curve 333 . This compression ratio allows the user to select a desired degree of compression above a threshold over a wide range to best suit the application and the capabilities of the matching system. In all cases, the distortion is zero under steady state conditions.

Turning to Figures 14 through 16, there is shown a series of graphs reflecting a signal before and after the signal is processed by the soft chopping engine 321 of the soft chopping engine 320, according to various user specified soft chopping inputs. The peak digital signal can vary from peak 0 to 1. For example, Figure 16 shows that the output sine wave 346 closely follows the input when the soft chopping input is set to a relatively small signal value of 0.25. Sine wave 345. Therefore, Figure 14 reflects that the signal is almost uncompressed when the level is low.

In contrast, Figures 15 through 17 illustrate the effect of increasing the soft chop input from .25 to, for example, 50 (Figure 15), 1.0 (Figure 16), and 2.0 (Figure 17). Figure 15 shows only a slight decrease in the maximum and minimum peaks of the output sine wave 351 compared to the input sine wave 350, reflecting the extremely slight compression of the signal for one of the peaks with full scale Vz. Figure 16 shows a slightly larger decrease in one of the maximum and minimum peaks of the output sine wave 356 compared to the input sine wave 355, reflecting moderate compression for a signal that would otherwise just reach the digital cutoff limit. Figure 17 shows one or even greater reduction in the maximum and minimum peaks of the output sine wave 361 compared to the input sine wave 360. In the exemplary embodiment of FIG. 17, the bass soft-clipping engine 321 causes the output sine wave 361 to smoothly flatten at maximum and minimum peaks slightly less than 1 and -1, respectively, preventing the original sine wave from coming from the allowable limit. Two times the input signal is severely distorted while minimizing the smaller signal.

In principle, the system 200 with the user interface 10 can use, for example, a Flowstone digital signal processing (DSP) programming software available from DSP Robotics at www.dsprobotics.com., for example, on a personal computer or Implemented on a laptop platform. The computer or platform can include a memory component that can include a computer readable medium for implementing one of the systems 200 and a user interface 10 for optimizing the audio response of the audio playback system.

System 200 and user interface 10 can be implemented in software, firmware, hardware, or any combination thereof. In a mode, a system with a user interface 10 The 200 series is implemented in software (as an executable program) and is executed by one or more dedicated or general-purpose digital computers, such as a personal computer (PC; IBM compatible, Apple compatible or otherwise), personal digital assistant, workstation , microcomputer, host computer, computer network, "virtual network" or "internet cloud computing device". In another mode, the system 200 with the user interface 10 is, for example, a laptop, a handheld MP3 player, a mobile phone, a car stereo system, a home stereo system, or any other Implemented in a firmware in a mobile or fixed platform or device. The implementation and operation of system 200 and user interface 10 are independent of the operating system of the base computer or device and will work on any operating system, such as Android, iOS, Microsoft Windows, Linux, Unix, and the like.

In one embodiment, system 200 can be used by a user to "tune" a predetermined audio playback system to maximize the volume output of all frequencies of the system without forming unwanted signals or distortion in the signal. The development software can be used in conjunction with system 200 to further "tune" the audio response of the audio playback system. System 200 can be implemented in conjunction with a user interface, such as user interface 10, to permit a user to select a value for each of the inputs described above for user interface 10. A consumer version of the user interface 10 (which may have fewer consumer selectable inputs) may be implemented in conjunction with the system 200.

In terms of hardware architecture, a computer or device on which system 200 operates includes a processor, memory, and one or more input and/or output (I/O) devices (or peripherals) via a The end interfaces are coupled to each other in a communication manner. As is well known in the art, the native interface can be, for example, but not limited to () one or more bus bars or other wired or wireless connections. The memory may include volatile memory components (eg, random access memory (RAM, such as DRAM, SRAM, SDRAM, etc.)) and non-volatile memory components (eg, ROM, hard drive, magnetic tape, CDROM, etc.) Any one or a combination. The memory can also incorporate electronic, magnetic, optical, and/or other types of storage media.

System 200 and user interface 10 can include one or more software programs that can be stored on any computer readable medium for use by or in connection with any computer related system or method. A computer readable medium is an electronic, magnetic, optical or other physical device or component that can acquire or store a computer program for use by or in connection with a computer related system or method. System 200 and user interface 10 can be implemented in any type of computer readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a processor-containing system, or an executable system, The device or device that uses the instructions and other systems that execute the instructions) is used or used in conjunction with it.

If implemented in hardware, system 200 and user interface 10 can also be implemented by any one or combination of the following techniques, each of which is well known in the art: having logic for implementing data signals One (or more) discrete logic circuits of functional logic gates, one special application integrated circuit (ASIC) with appropriate combination logic gates, one (or more) programmable gate arrays (PGA), one programmable Gate array (FPGA), etc.

While the invention has been described with respect to the specific embodiments of the present invention, it will be understood that Therefore, the disclosure herein is intended to be illustrative only and It is not to be limited in its scope, and the scope of the claims and the full extent of any equivalents thereof.

10‧‧‧User interface

20‧‧‧Issue engine user interface

22‧‧‧Total power-on-off switcher

24‧‧‧ Prescaler

26‧‧‧Automatic prescaler switcher

30‧‧‧second-order filter

31‧‧‧ frequency

32‧‧‧ Gain

33‧‧‧Quality Factor (Q)

35‧‧‧Switcher

38‧‧‧Chart

50‧‧‧Dynamic engine user interface

52‧‧‧Compression start

54‧‧‧Compression reduction

56‧‧‧Delay

58‧‧‧Compression ratio

60‧‧‧frequency limit (F limit)

62‧‧‧ threshold

64‧‧‧Compression reduction threshold

66‧‧‧Preview

68‧‧‧After the crossover setting

70‧‧‧Automatic post-frequency on/off switch

72‧‧‧Switching on/off switch

74‧‧‧Chop indicator light

76‧‧‧Reset button

80‧‧‧ bass boost engine user interface

82‧‧‧ frequency

84‧‧‧Upgrade

86‧‧‧ threshold

88‧‧‧Compression reduction threshold

90‧‧‧ Preview

92‧‧‧ bass high pass filter

94‧‧‧Compression start

96‧‧‧Compression reduction

98‧‧‧Delay

100‧‧‧Compression ratio

102‧‧‧Soft chopping

104‧‧‧Soft Chop Master On/Off Switcher

125‧‧‧System

130‧‧‧Audio signal/input audio signal/signal

140‧‧‧ Equalization engine

150‧‧‧Dynamic Engine

160‧‧‧ Bass boost engine

170‧‧‧ Output signal

162‧‧‧low pass filter

164‧‧‧Compressor/limiter

200‧‧‧ system

202‧‧‧ Prescaler engine

208‧‧‧Input block

209‧‧‧Input audio signal

210‧‧‧ Equalization engine

211‧‧‧Parametric Filter Engine

213‧‧‧Filter Engine

214‧‧‧Bypass engine

215‧‧‧Adjustable Q Qualcomm Engine

216‧‧‧Adjustable Q low-pass engine

217‧‧‧ Peak Processing Engine

218‧‧‧ bass class processing engine

219‧‧‧Filter setting

220‧‧‧ frequency

221‧‧‧ Gain

222‧‧‧Quality Factor (Q)

232‧‧‧Output block

233‧‧‧ audio signal

248‧‧‧Input block

249‧‧‧Input audio signal

250‧‧‧Dynamic Engine

251‧‧‧Dynamic Filter Engine

252‧‧‧bypass filter engine

253‧‧‧First-order high-pass filter engine

254‧‧‧First-order low-pass filter engine

257‧‧‧Dynamic Processing Engine

258‧‧‧ Compressor

260‧‧‧Restrictor setting block

261‧‧‧Compression starting rate

262‧‧‧Compression reduction rate

263‧‧‧ threshold

264‧‧‧Compression reduction threshold

265‧‧‧Compression reduction delay

266‧‧‧ signal

268‧‧‧Limiter Processing Engine

269‧‧‧Limiter Engine

271‧‧‧Compressor setting block

273‧‧‧ Preview

275‧‧‧Preview delay engine

276‧‧‧Delay Processing Engine

277‧‧‧Preview delay processing engine

278‧‧‧Compression ratio

279‧‧‧gain reduction engine

280‧‧‧gain reduction processing engine

282‧‧‧Dynamic integration engine

283‧‧‧Reorganized engine

285‧‧‧Preventional forming engine

286‧‧‧High-pass filter engine

288‧‧‧Output block

289‧‧‧Audio signal/output signal

300‧‧‧ Bass Boost Engine

301‧‧‧ bass filter engine

302‧‧‧ fourth-order high-pass engine

303‧‧‧ fourth-order low-pass engine

305‧‧‧ bass protection engine

306‧‧‧ bypass block

307‧‧‧Second-level high-pass engine

309‧‧‧ Bass boost engine

310‧‧‧Delay Processing Engine

311‧‧‧User specified gain

313‧‧‧ Bass Compressor Engine

314‧‧‧ bypass block

315‧‧‧ Bass Compressor Processing Engine

317‧‧‧ Bass Integration Engine

318‧‧‧Reorganization engine

320‧‧‧ bass soft cut engine

321‧‧‧ bass soft cut processing engine

323‧‧‧After the crossover engine

324‧‧‧post-frequency processing engine

Figure 1 illustrates the filtering of one of the audio signals by a high pass filter in conjunction with a limiter.

Figure 2 illustrates the filtering of one of the audio signals by a high pass filter without a limiter.

3 illustrates a frequency independent constant deviation of a speaker driver resulting from an enhancement of an exemplary frequency dependent threshold of one of a compressor/limiter of an exemplary bass boost engine.

Figure 4 illustrates an example user interface for a first-class engine.

Figure 5 illustrates an exemplary user interface for a dynamic engine.

Figure 6 illustrates an exemplary user interface for a bass boost engine.

7 is a block diagram illustrating an exemplary method for optimizing an audio signal of an audio playback system.

FIG. 8 is a block diagram illustrating an exemplary bass boost engine of one of the methods described in FIG.

Figure 9 is a block diagram illustrating an exemplary embodiment of an embodiment of the present invention.

Figure 10 is a detailed block diagram illustrating one of the exemplary embodiments of an equalization engine of the embodiment shown in Figure 9.

11 is a detailed block diagram illustrating one of the exemplary embodiments of one of the dynamic engines of the embodiment shown in FIG.

Figure 12 is a detailed block diagram illustrating one of the alternative embodiments of a dynamic engine.

Figure 13 shows an example steady state signal response for one of the signals processed by an example dynamic engine.

Figure 14 shows the signal response after processing a signal through an exemplary bass soft chopping engine of an example bass boost engine.

Figure 15 shows a signal before and after processing the signal by one of the example bass boost engines instead of the bass soft chopping engine.

Figure 16 shows a signal before and after processing the signal through another alternative bass soft chopping engine of an example bass boost engine.

Figure 17 shows a signal before and after processing of the signal by another alternative bass soft chopping engine that is passed through an exemplary bass boost engine.

125‧‧‧System

130‧‧‧Audio signal/input audio signal/signal

140‧‧‧ Equalization engine

150‧‧‧Dynamic Engine

160‧‧‧ Bass boost engine

170‧‧‧ Output signal

Claims (43)

A computer program product stored on a computer readable medium, the computer program product having computer executable code instructions executable by a computer processor to optimize sound reproduction of an audio system, the computer executable code instructions including a first code command for adjusting a characteristic of a plurality of frequency bands corresponding to an audio signal; a second code command for reducing a first user to be processed by the first code command Adjusting a voltage of one of the audio signals of the threshold to force one of the speaker drivers of the audio system to expect a maximum amount of voltage; and a third code command for improving the lowering of the processing by the second code command Retrieving a bass response of the audio signal at a bass resonance frequency of one of the speaker drivers, the third code instructions including a fourth code command for reducing a second user processed by the third code command The voltage of the audio signal of the threshold can be adjusted to force the desired maximum amount of deviation of the speaker driver. The computer program product of claim 1, wherein the first code instructions are configured to process the audio signal through a plurality of second order filters corresponding to respective frequency bands adjusted by a user for the characteristics. The computer program product of claim 1, wherein the characteristics corresponding to the plurality of frequency bands comprise at least one of a gain, a center frequency of each of the plurality of frequency bands, and a quality factor. The computer program product of claim 3, wherein the gain, the center frequency And the quality factors are each independently adjustable by a user. The computer program product of claim 4, wherein the gain is continuously or discretely adjustable from about -12 dB to about 12 dB. The computer program product of claim 4, wherein the center frequency is continuously or discretely adjustable from about 20 Hz to about 20 kHz. The computer program product of claim 4, wherein the quality factor is continuously or discretely adjustable from about 0.1 to about 4.0. The computer program product of claim 1, wherein the second code instructions are configured to process the audio signal according to an independently adjustable and user definable setting, the independently adjustable and user definable settings including At least one of a compression start rate, a compression reduction rate, a compression start threshold, and a compression reduction threshold. The computer program product of claim 1, wherein the first user definable threshold is continuously or discretely adjustable from about 0 dB to about -12 dB. The computer program product of claim 1, wherein the third code instructions are configured to process the audio signal according to an independently adjustable and user definable setting, the independently adjustable and user definable settings including At least one of a bass compression start rate, a bass compression reduction rate, a bass compression start threshold, and a bass compression reduction threshold. The computer program product of claim 1, wherein the second user definable threshold is continuously or discretely adjustable from about 0 dB to about -12 dB. A system for optimizing sound reproduction of an audio system, comprising: one or more processors; a memory; a first-class engine stored in the memory, the equalization engine including a first code instruction to cause the one or more processors to adjust characteristics of a plurality of frequency bands corresponding to an audio signal; a dynamic engine stored in the memory, the dynamic engine including second code instructions to cause the one or more processors to dynamically reduce more than a first user definable by the equalizing engine Limiting a voltage of the audio signal to force a maximum amount of deviation of one of the speaker drivers of an audio system; and a bass enhancement engine stored in the memory, the bass enhancement engine including a third code command, And the like for causing the one or more processors to boost a bass response of the audio signal processed by the dynamic engine that is lower than a bass resonance frequency of one of the speaker drivers; and a fourth code command to cause the One or more processors reduce the voltage of the audio signal processed by the bass boost engine by more than a second user definable threshold to force the speaker driver to be in the period Maximum deviation. The system of claim 12, wherein the first code instructions are configured to process the audio signal by a plurality of second order filters corresponding to respective frequency bands for adjustment of the characteristics. The system of claim 12, wherein the characteristics corresponding to the plurality of frequency bands comprise at least one of a gain, a center frequency of each of the plurality of frequency bands, and a quality factor. The system of claim 14, wherein the gain, the center frequency, and the quality factor are each adjustable by a user. The system of claim 12, wherein the dynamic engine includes independently adjustable settings corresponding to at least one of the group consisting of: a compression initiation rate, a compression reduction rate, a delay period, and a Compression ratio, a threshold, a compression reduction threshold, or a preview. The system of claim 12, wherein the bass enhancement engine includes independently adjustable settings corresponding to at least one of the group consisting of: a bass boost amount, a compression start rate, and a compression reduction rate , a delay period, a compression ratio, a threshold, a compression reduction threshold, a look-ahead, a high-pass filter setting, or a soft-cut setting. A method for optimizing sound reproduction of an audio system, comprising: providing a computer readable medium encoded by a first computer program for independently adjusting characteristics of a plurality of frequency bands corresponding to an audio signal; Providing a computer readable medium encoded by a second computer program for dynamically reducing a voltage of the audio signal processed by the first computer program by more than a first user adjustable compression threshold To force a maximum deviation of one of the speaker drivers; providing a computer readable medium encoded by a third computer program for causing the voltage of the audio signal processed by the second computer program to fall below a first use The voltage reduction can be dynamically stopped when the compression reduction threshold is adjusted; and a computer readable medium encoded by a fourth computer program is provided. And increasing a bass frequency lower than about one of the speaker drivers of the audio system; providing a computer readable medium encoded by a fifth computer program for dynamically reducing processing by the fourth computer program And more than a second user can adjust the voltage of the audio signal of the compression start threshold to force a maximum deviation of one of the speaker drivers; and provide a computer readable medium encoded by a sixth computer program The voltage reduction is dynamically stopped to return the voltage to a boosted state when the voltage of the audio signal processed by the fifth computer program falls below a second user adjustable compression reduction threshold. The method of claim 18, wherein the characteristics corresponding to the plurality of frequency bands comprise at least one of a gain, a center frequency of each of the plurality of frequency bands, and a quality factor. The method of claim 18, further comprising encoding, by means of a seventh computer program, a computer readable medium for immediately chopping more than one user adjustable soft cut threshold by the sixth computer program The voltage of the audio signal further forces the maximum amount of deflection of one of the speaker drivers. A computer program product stored on a computer readable medium, the computer program product having computer executable code instructions executable by a computer processor for enhancing bass response of an audio system, the computer executable code instructions including : a first code command for boosting a voltage corresponding to a low frequency of an audio signal below one selected frequency; and a second code instruction, the method comprising: reducing the voltage of the audio signal that is boosted by the first code command by more than a user adjustable threshold, the second code instructions being configured to force the One of the speaker drivers is independently offset by frequency. The computer program product of claim 21, wherein the selected frequency substantially corresponds to a bass resonance frequency of one of the speaker enclosures associated with the speaker driver. The computer program product of claim 21, further comprising third code instructions, the third code instructions comprising a high pass filter for processing the audio signal prior to processing the audio signal by the second code instructions. The computer program product of claim 21, further comprising fourth code instructions for recombining the reduced audio signal with the audio signal above the selected frequency. The computer program product of claim 24, further comprising fifth code instructions for soft clipping the recombined audio signal. The computer program product of claim 21, further comprising sixth code instructions for delaying the audio signal above the selected frequency. The computer program product of claim 21, wherein the compressor includes separate compression initiation and compression reduction thresholds. A computer program product stored on a computer readable medium, the computer program product having computer executable code instructions executable by a computer processor for enhancing bass response of an audio system, the computer executable code instructions including : a first code command, which is used to determine that a lower than a limited frequency is to be promoted a bass signal rate of one of the audio signals; a second code command for boosting a voltage of the audio signal corresponding to the low frequency; and a third code command for reducing the audio signal One of the voltages of the compressor, the third code instructions are configured to force one of the speaker drivers to independently deviate from the frequency. The computer program product of claim 28, wherein the third code instructions are configured to process the self-adjustable and user definable settings according to at least one of the group consisting of: Audio signal: a compression start rate, a compression reduction rate, a compression reduction delay, a compression ratio, an adjustable frequency bypass, a compression start threshold, a compression reduction threshold, or a look-ahead. The computer program product of claim 28, further comprising fourth code instructions, the fourth code instructions comprising for limiting a voltage of the audio signal based on a frequency dependent threshold for forming a zero filter frequency shift Bit. The computer program product of claim 28, wherein the first code instructions comprise a high pass filter and a low pass filter for establishing a range of bass frequencies to be boosted below the selected frequency. A computer program product stored on a computer readable medium, the computer program product having computer executable code instructions executable by a computer processor for enhancing a response of an audio system, the computer executable code instructions comprising : a first code command, which includes a voltage for reducing one of the audio signals A compressor, the first code instructions configured to force a frequency independent deviation of a speaker driver, the first code instructions being configured to be processed according to a user definable setting comprising one of the following: The audio signal: a compression start rate, a compression reduction rate, a frequency bypass, a compression start threshold, and a look-ahead. The computer program product of claim 32, wherein the setting further comprises at least one of a compression ratio and a compression reduction threshold. The computer program product of claim 32, further comprising a second code command, the second code command comprising a low pass filter for filtering the audio signal prior to processing the audio signal by the first code command Device. The computer program product of claim 34, wherein the low pass filter is a first order low pass filter. The computer program product of claim 32, further comprising the voltage for the soft chopping of the audio signal processed by the first code command that exceeds an adjustable soft chop threshold to further force the speaker driver A third code instruction with a maximum deviation. The computer program product of claim 32, further comprising a fourth code command, the fourth code command comprising: filtering the audio signal after processing the audio signal by the first code command to force a frequency A high-pass filter that is one of the dependent thresholds. A method for optimizing sound reproduction of an audio system, comprising: providing a computer readable medium encoded by a first computer program for filtering a bass signal of an audio signal, the first computer program include A low pass filter configured to transmit a low bit rate below an adjustable low pass filter setting and a high pass filter configured to transmit a low bit rate above an adjustable high pass filter setting, The low pass filter setting includes a frequency higher than one of the high pass filter settings; providing a computer readable medium encoded by a second computer program for enhancing the audio signal transmitted by the first computer program Bass response; and providing a computer readable medium encoded by a third computer program for dynamically reducing a voltage of the audio signal transmitted by the second computer program over an adjustable threshold to force One of the maximum safety deviations of one of the speaker drivers associated with the audio system. The method of claim 38, wherein the low pass filter is a fourth order low pass filter. The method of claim 38, wherein the low pass filter setting is set to substantially one of the resonant frequencies of the speaker driver. The method of claim 38, wherein the high pass filter is a second order high pass filter. The method of claim 38, further comprising providing a computer readable medium encoded by a fourth computer program for causing the voltage of the audio signal processed by the third computer program to fall below an adjustable compression reduction The voltage is dynamically stopped at the threshold to return the voltage to a boosted state. The method of claim 42, further providing a computer readable medium encoded by a fifth computer program for soft chopping by the fourth computer program The voltage of the audio signal that exceeds an adjustable soft cutoff threshold is processed to further force a maximum amount of deviation of one of the speaker drivers.