Sound system

• US 10,306,358 B2
• Filed: 10/27/2017
• Issued: 05/28/2019
• Est. Priority Date: 04/27/2015
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Faller, Christof, Schmidt, Markus, Walther, Andreas, Borss, Christian, Saari, Ville, Goetz, Philipp
• Primary Examiner(s): Jamal, Alexander
• Application Number:
  US15/795,527
• Publication Number:
  US 20180103316A1
• Time in Patent Office: 578 Days
• Field of Search: 381 13, 381300, 381306, 381 97, 381 943
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 2201/403 Linear arrays of transducers
• CPC Class Codes: H04R 2430/03 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04R 2430/23 Direction finding using a sum-delay beam-former
• CPC Class Codes: H04R 2499/15 Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops
• CPC Class Codes: H04R 5/02 Spatial or constructional arrangements of loudspeakers
• CPC Class Codes: H04R 5/04 Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments combinations of amplifiers H03F3/68; stereophonic systems H04S
• CPC Class Codes: H04S 2420/07 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04S 5/005 of the pseudo five- or more-channel type, e.g. virtual surround

Abstract

A calculation unit for a sound system includes an input terminal, a processor and an output terminal. The input terminal has the purpose to receive an audio stream to be reproduced using the sound system. The output terminal has the purpose to control the sound system based on a first and a second plurality of individual audio signals. The processor is configured to calculate the first plurality of audio signals such that beamforming is performed by the array and to calculate the second plurality of individual audio signals to perform, using the sound system, direct sound suppression such that sound is canceled towards a listening direction. Furthermore, the processor filters at least the second plurality using a second passband characteristic including a second portion of the entire frequency range.

Claims

1. A calculation unit for a sound system comprising an array including a plurality of transducers, the calculation unit comprising:

an input terminal for receiving an audio stream to be reproduced using the sound system and including a frequency range;

a processor; and

an output terminal for controlling the sound system,

wherein the processor is configured to calculate a first plurality of individual audio signals for the transducers of the array such that beamforming is performed by the array, wherein the first plurality of individual audio signals comprises a frequency range corresponding to a first portion of the frequency range of the audio stream,

wherein the processor is configured to calculate a second plurality of individual audio signals for the transducers of the sound system to perform, using the sound system, direct sound suppression such that sound is canceled towards a listening direction,

wherein the processor is configured to filter the second plurality of individual audio signals using a second passband characteristic comprising a second portion of the frequency range of the audio stream, wherein the second portion differs from the first portion;

wherein the beamforming performed via the first plurality of individual audio signals is performed by using at least three audio signals such that at least three transducers are controlled;

wherein the first plurality of audio signals and the second plurality of audio signals are added using the mixer to be output to the one array comprising the transducers of the sound system which are controlled by the first and the second plurality of individual audio signals.

2. The calculation unit according to claim 1, wherein the direct sound suppression is performed using sound cancelation and/or dipoling.

3. The calculation unit according to claim 2, wherein the sound cancelation comprises a manipulation of the beamforming within the second portion of the frequency range of the audio stream.

4. The calculation unit according to claim 2, wherein the sound cancelation corrects the beamforming performed via the first plurality of individual audio signals within the second portion of the frequency range.

5. The calculation unit according to claim 1, wherein second portion is a subset of the first portion.

6. The calculation unit according to claim 1, wherein the processor is configured to filter the first plurality of individual audio signals using a first passband characteristic comprising the first portion of the frequency range of the audio stream.

7. The calculation unit according to claim 2, wherein the direct sound suppression is performed using dipoling which is performed by providing at least two individual audio signals of the second plurality of individual audio signals for two different transducers in a phase-shifted manner or by providing at least two groups of individual audio signals of the second plurality of individual audio signals for two groups of different transducers in a phase-shifted manner.

8. The calculation unit according to claim 7, wherein the two individual audio signals or the two groups of individual audio signals are phase-shifted by 180°

.

9. The calculation unit according to claim 1, wherein the second portion of the frequency range is lower than the first portion of the frequency range.

10. The calculation unit according to claim 1, wherein the beamforming performed via the second plurality of individual audio signals is performed by using at least three audio signals such that at least three transducers are controlled.

11. The calculation unit according to claim 1, wherein different transducers are controlled via the first plurality of individual audio signals and via the second plurality of individual audio signals.

12. The calculation unit according to claim 1, wherein all transducers of the array are controlled via the first plurality of individual audio signals and wherein a subset of transducers of the sound system is controlled via the second plurality of individual audio signals.

13. The calculation unit according to claim 1, wherein the processor is configured to calculate a third plurality of individual audio signals for the transducers of the sound system such that dipoling is performed by the sound system and wherein the processor is configured to filter the third plurality of individual audio signals using a third passband characteristic comprising a third portion of the frequency range of the audio stream, wherein the third portion differs from the first portion and the second portion.

14. The calculation unit according to claim 1, wherein the processor is configured to calculate a third plurality of individual audio signals for the transducers of the sound system comprising a stereophonic reproduction,

wherein the processor is configured to filter the third plurality of individual audio signals using a third passband characteristic comprising a third portion of the frequency range of the audio stream, wherein the third portion of the frequency range differs from the first and second portion of the frequency range.

15. The calculation unit according to claim 1, wherein transducers of the sound system which are arranged furthest of each other are controlled via the second plurality of individual audio signals or wherein transducers of the sound system which are arranged furthest of each other are controlled via the third plurality of individual audio signals.

16. The calculation unit according to claim 1, wherein the processor calculates the first plurality of individual audio signals x_i based on the formula

x_i(t)=HPF{s(t+τ

_i)},

wherein HPF complies with the first passband characteristic and τ

_i with a steering delay of transducers of the array, and

wherein the processor calculates the second plurality of individual audio signals x₁ and x_n based on the formula

x₁(t)=LPF{s(t)}

x_N(t)=−

LPF{s(t)},

wherein LPF complies with the second passband characteristic.

17. A sound system comprising:

the processor according to claim 1 and an array including the plurality of transducers.

18. The system according to claim 17, further comprising at least two additional separated loudspeaker elements.

19. The system according to claim 18, wherein each of the two separated loudspeaker elements comprises an array including at least three transducers being arranged on a flexed line.

20. A method for calculating a sound reproduction for a sound system comprising an array including a plurality of transducers, the method comprising:

receiving an audio stream to be reproduced using the array and including a frequency range;

calculating a first plurality of individual audio signals for the transducers of the array such that beamforming is performed via the array, wherein the first plurality of individual audio signals comprises a frequency range corresponding to a first portion of the frequency range of the audio stream;

calculating a second plurality of individual audio signals for the transducers of the sound system to perform, using the sound system, direct sound suppression such that sound is canceled towards a listening direction;

filtering the second plurality of individual audio signals using a second passband characteristic comprising a second portion of the frequency range of the audio stream, wherein the second portion differs from the first portion;

outputting the individual audio signals of the first and second plurality in order to control the sound system; and

adding the first plurality of audio signals and the second plurality of audio signals using the mixer to be output to the one array comprising the transducers of the sound system which are controlled by the first and the second plurality of individual audio signals.

21. A non-transitory digital storage medium having a computer program stored thereon to perform the method for calculating a sound reproduction for a sound system comprising an array including a plurality of transducers, said method comprising:

receiving an audio stream to be reproduced using the array and including a frequency range;

calculating a first plurality of individual audio signals for the transducers of the array such that beamforming is performed via the array, wherein the first plurality of individual audio signals comprises a frequency range corresponding to a first portion of the frequency range of the audio stream;

calculating a second plurality of individual audio signals for the transducers of the sound system to perform, using the sound system, direct sound suppression such that sound is canceled towards a listening direction;

filtering the second plurality of individual audio signals using a second passband characteristic comprising a second portion of the frequency range of the audio stream, wherein the second portion differs from the first portion;

outputting the individual audio signals of the first and second plurality in order to control the sound system; and

adding the first plurality of audio signals and the second plurality of audio signals using the mixer to be output to the one array comprising the transducers of the sound system which are controlled by the first and the second plurality of individual audio signals;

when said computer program is run by a computer.

22. A calculation unit for a sound system comprising an array including a plurality of transducers, the calculation unit comprising:

an input terminal for receiving an audio stream to be reproduced using the sound system and including a frequency range;

a processor; and

an output terminal for controlling the sound system,

wherein the processor is configured to calculate a first plurality of individual audio signals for the transducers of the array such that beamforming is performed by the array, wherein the first plurality of individual audio signals comprises a frequency range corresponding to a first portion of the frequency range of the audio stream,

wherein the processor is configured to calculate a second plurality of individual audio signals for the transducers of the sound system to perform, using the sound system, direct sound suppression such that sound is canceled towards a listening direction,

wherein the processor is configured to filter the second plurality of individual audio signals using a second passband characteristic comprising a second portion of the frequency range of the audio stream, wherein the second portion differs from the first portion;

wherein the direct sound suppression is performed using sound cancelation, wherein the sound cancelation corrects second plurality of individual audio signals within the second portion of the frequency range using beamforming performed via the first plurality of individual audio signals;

wherein the first plurality of audio signals and the second plurality of audio signals are added using the mixer to be output to the one array comprising the transducers of the sound system which are controlled by the first and the second plurality of individual audio signals.

23. A calculation unit for a sound system comprising an array including a plurality of transducers, the calculation unit comprising:

an input terminal for receiving an audio stream to be reproduced using the sound system and including a frequency range;

a processor; and

an output terminal for controlling the sound system,

wherein the processor is configured to calculate a first plurality of individual audio signals for the transducers of the array such that beamforming is performed by the array, wherein the first plurality of individual audio signals comprises a frequency range corresponding to a first portion of the frequency range of the audio stream,

wherein the processor is configured to calculate a second plurality of individual audio signals for the transducers of the sound system to perform, using the sound system, direct sound suppression such that sound is canceled towards a listening direction,

wherein the processor is configured to filter the second plurality of individual audio signals using a second passband characteristic comprising a second portion of the frequency range of the audio stream, wherein the second portion differs from the first portion;

wherein the beamforming performed via the first plurality of individual audio signals is performed by using at least three audio signals such that at least three transducers are controlled,

wherein second portion is a subset of the first portion;

wherein the first plurality of audio signals and the second plurality of audio signals are added using the mixer to be output to the one array comprising the transducers of the sound system which are controlled by the first and the second plurality of individual audio signals.