DE102008017084A1 - Audio system for use in vehicle, has loudspeaker arranged in driving direction seen in front area of vehicle for transmitting sound signal - Google Patents

Abstract

The invention relates to an arrangement of an audio system in a vehicle with an optimized for the perception of sound low frequencies vehicle interior. The audio system has at least one in the front region of the vehicle (1) arranged loudspeaker (7) suitable for the transmission of audio frequencies less than 200 Hz and in the region of the center tunnel, the doors or the footwell of the vehicle (1). According to the invention, a sound-absorbing means is arranged in the rear region of the vehicle (1) which consists of a partition (10) at least partially closing off a volume behind it, the partition (10) consisting of a material which is partially permeable to sound waves.

Description

The The invention relates to an arrangement of an audio system in a vehicle with a for the sound perception of low frequencies optimized vehicle interior.

previously known are audio systems used for transmission low frequencies have loudspeakers in the rear area of the vehicle, which preferably as a bass speaker of large diameter in the rear Trays of the vehicle to be installed or in the trunk of the vehicle are arranged. Furthermore, it is already known speakers in the front To arrange area of vehicles, in particular speakers for transmission high frequencies in the area of the dashboard and woofers or Broadband speakers are located in the area of the doors.

The Arrangement of bass speakers is in terms of their location largely flexible, because sound events with frequencies smaller 120 Hz only very inaccurate and frequencies less than 80 Hz from humans in terms of their source in small rooms not can be located. Therefore, various installation situations are common in the vehicle, which have various disadvantages. The arrangement of bass speakers in the door area often leads too disturbing Background noise occurring vibrations as well as problems in the door seal. The arrangement requires in particular woofers of large diameter in the rear shelf often a reinforcement the carrying structure. Furthermore, for all installation situations Long-wave sound waves of lower frequencies are problematic as they hardly absorbed in the vehicle and reflected on the inner walls tend to form standing waves, which have a negative sound perception because of the audible Cause multiple reflections. The problem here is the small volume of space within the vehicle, which in particular in the long-wave range leading to the formation of standing waves in the vehicle.

task The invention is therefore an audio system of a vehicle so to make it a natural one Sound perception especially in the range of low frequencies allows and the formation of standing waves is largely avoided.

The The object is achieved with an audio system according to claim 1.

According to the invention advantageous has a vehicle with an audio system at least one, in the direction of travel seen in the front of the vehicle arranged speakers for transmission a sound signal, wherein in the rear of the vehicle to avoid reflections and thus the training of standing Waves a sound absorbing agent is arranged.

The Use of absorbers as an interface to other volumes reduced standing waves in the vehicle. The oblong expression of the Vehicle interior is used in such a way that the deep sound pressure generator are installed at a fixed end of an acoustic line and its emitted sound pressure wave at the other end of the acoustic line steamed by absorber becomes. The typical roar In the bass range in vehicle cabs can be strong in this way be reduced. It becomes a linearization in the frequency domain achieved and improves the temporal behavior of transients. Furthermore, the sound pressure distribution in the vehicle becomes more uniform.

The Arrangement is especially when using bass speakers or of broadband speakers emitting in the low frequency range significant because these long-wave sound signals due to the reflection and low absorption at the interfaces of the interior for formation tilting standing waves. In an advantageous embodiment, these speakers in the area of the center tunnel, the doors or the footwell the vehicle as possible arranged far to the front of the cabin.

In a preferred embodiment For example, the speaker (s) are attached to a rigid, load bearing structure Center tunnels arranged. The speakers can be in one possible Design quasi "caseless" on one interface be installed to the vehicle interior, so that the entire space of the behind volume as bass volume is available.

The Sound-absorbing agent according to the invention from the combination of arranged in the rear of the vehicle partition and an underlying Volume formed. The separation closes the bulk of the Volume, ideally the whole volume, of the vehicle interior from. The separation consists of a frictional for sound waves Material which is fixed in place. Through the passage of the Sound into the underlying volume of sufficient size the sound energy largely destroyed. It thus reduces one Reflection of the sound waves back to the source.

There especially low-frequency, standing waves should be avoided the separation is at least for Sound waves of frequencies less than 200 Hz partially transparent with one for these frequencies formed frictional material.

An advantageous embodiment, which is particularly suitable for the design of rear shelves, an embodiment of a rigid, preferably metal mesh sufficient strength and mass, which is provided with a textile, felt-like or leather or artificial leather-like cover.

In an advantageous embodiment, the partially transparent for sound waves separation consists of a steel mesh, which is preferably 0.5 to 1.5 mm thick. Its surface is provided with openings which cover 30 to 70% of the (opening area.The grid has a weight per unit area of 1 to 10 kg / m ² and is provided with a frictional covering with a flow resistance of 200 to 2000 Pas / m and a basis weight between 50 and 600 g / m ² , which is fixed on the grid by at least partial gluing, stringing, etc. The grating may consist not only of steel but also of another metal or of an alternative material of similar rigidity having the said weight per unit area.

In In a preferred embodiment, the separation is considered to be appropriate executed Rear shelf formed, which is the underlying volume of a Trunk delimited. Another embodiment is the alternative or additional Arrangement of a Partly transparent sound waves Standing wall in the area behind the rear row of seats.

A Another embodiment is the use of the surfaces of a vehicle seat (backrest and / or seat), which for Sound waves partially trained become. Here, in an advantageous embodiment, the bearing / rigid Seat structure pierced, with upholstery and overlying coverings acoustically transparent are designed.

at Use of the rear row of seats and the rear shelf as a partition and their design as for Sound waves partially transparent the trunk volume is completed as a partial volume, which for the Absorption of the sound energy is needed.

Further advantageous embodiments will be apparent from the dependent claims and the embodiment.

in this connection demonstrate:

1 a schematic diagram of the audio system according to the invention in the vehicle,

2 a schematic diagram of the speaker and absorber arrangement as an acoustic line,

3 a schematic diagram of the speaker assembly in a plan view.

In 1 is a vehicle 1 with an exemplary arrangement of speakers 7 shown, which in its rear area a stylized illustrated, designed as a rear shelf partition 10 having. The separation 10 separates a volume 9 from the vehicle interior 5 from and is partially transparent for sound waves. By the arrangement of the speakers 7 in the front area of the vehicle and the elongated extent of the vehicle interior 5 as well as the arrangement of the separation 10 and volume behind 9 existing, sound-absorbing agent at the end of the vehicle 1 is considered idealized, one in 2 stylized illustrated acoustic line created. The acoustic line will follow with its equivalent in the vehicle 1 shown. At the beginning of the acoustic line is the sound source (loudspeaker 7 ), which generates a sound signal, the line (cab 2 ) by absorptive separation 3 and the sonic killer 4 (Separation 10 and volume 9 ) may be considered open in terms of their properties. The absorber reduces a return of the sound wave by the reflection, so that multiple reflections are avoided due to stagnant waves. The arrangement of the speakers 7 is shown here by way of example. For the effect according to the invention, their arrangement is in the front region of the vehicle 1 necessary. In the vehicle 1 There are several arranged in consecutive rows seats 6 , wherein at least the rear row of seats is designed to be partially transparent to sound waves. In the present example is a permeable core 8th shown within a load-bearing seat structure, which is configured partially permeable through openings for sound waves. The volume 9 in the trunk of the vehicle 1 is thus the interior on the one hand by the separation 10 and on the other hand from the back of the seat 6 limited, both of which are designed to be partially transparent to sound waves. With the design of the breakthroughs in the rigid, load-bearing material, their distribution as well as size may be the suitability of the separation 10 as well as the core 8th to be effective for certain frequencies. The effect is exploited that a diffuse sound field propagates behind such an interface, the energy of which is absorbed in the subsequent volume.

3 shows a simplified embodiment of a speaker assembly of the audio system. In the area of the dashboard are tweeters 11 and in the mid-tunnel area are two woofers 7 with to the respective doors of the cabin 2 directed radiation arranged.

1

vehicle

2

cabin

3

absorptive partition wall

4

Dead End / Schallvernichter

5

Vehicle interior

6

seats

7

Woofer / Speaker / woofer

8th

core

9

volume

10

separation

11

tweeter

Claims (14)

Audio system in a vehicle ( 1 ) with at least one seen in the direction of travel in the front region of the vehicle ( 1 ) arranged loudspeakers ( 7 ) for transmitting a sound signal, wherein at the rear of the vehicle ( 1 ) A sound absorbing agent is arranged. Audio system according to claim 1, characterized in that the loudspeaker (s) ( 7 ) is suitable for transmitting sound frequencies below 200 Hz and in the area of the center tunnel, the doors or the footwell of the vehicle ( 1 ) are arranged. Audio system according to claim 2, characterized in that the loudspeakers ( 7 ) are arranged on a rigid, supporting structure of the center tunnel. Audio system according to one of the preceding claims, characterized in that the sound-absorbing means from the combination of a in the rear of the vehicle ( 1 ), an underlying volume at least partially final separation ( 10 ), the separation ( 10 ) consists of a partially soundproof material for sound waves. Audio system according to claim 4, characterized in that the separation ( 10 ) has a flow resistance of 200 to 2000 Pas / m. Audio system according to one of the preceding claims, characterized in that the sound-absorbing means is designed such that it consists of a volume lying behind it ( 9 ) at least partially final separation ( 10 ), the volume ( 9 ) and the separation ( 10 ) form a sound-absorbing absorber. Audio system according to one of claims 4 to 6, characterized in that the separation ( 10 ) is designed to be partially transmissive for frequencies less than 200 Hz for sound waves. Audio system according to one of the preceding claims 4-7, characterized in that the separation ( 10 ) consists of a stiff, provided with a plurality of openings material, which is provided with a textile cover. Audio system according to one of the preceding claims 4-8, characterized in that the separation ( 10 ) consists of a metal grid with a thickness of 0.5 to 3 mm, the surface of which is provided with openings which cover between 30 and 70% of the total area, wherein the metal grid has a basis weight of 1 to 10 kg / m ² and with a Covering is provided, which has a flow resistance of 200 to 2000 Pas / m and a basis weight between 50 and 600 g / m ² . Audio system according to one of the preceding claims 8 u. 9, characterized in that the textile cover covering the separation ( 10 ), by covering or gluing on the surface of the partition ( 10 ) is fixed. Audio system according to one of the preceding claims 4-10, characterized in that the sound-wave partially transparent separation ( 10 ) is designed as a rear shelf. Audio system according to one of the preceding claims 4-10, characterized in that the separation ( 10 ) is designed as a standing wall behind the rows of seats. Audio system according to one of the preceding claims, characterized in that the seat back and / or seat surface of a Row of seats for Sound waves partially transparent is trained. Audio system according to claim 13, characterized in that that leaning surfaces a row of seats and the rear shelf for sound are designed to be partially transparent and the underlying volume of a trunk largely from Divide the vehicle interior.