SOUND SYSTEM AND METHOD OF OPERATION THEREFOR

• US 20110002468A1
• Filed: 03/05/2009
• Published: 01/06/2011
• Est. Priority Date: 03/14/2008
• Status: Active Grant

• Current Assignee: MMD Hong Kong Holding Limited
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Tanghe, Loic Bernard
• Granted Patent: US 8,559,661 B2
• Time in Patent Office: Days
• US Class Current: 381/17
• CPC Class Codes: H04R 2205/022 Plurality of transducers corresponding to a plurality of sound channels in each earpiece of headphones or in a single enclosure
• CPC Class Codes: H04R 5/02 Spatial or constructional arrangements of loudspeakers
• CPC Class Codes: H04S 2400/05 Generation or adaptation of centre channel in multi-channel audio systems
• CPC Class Codes: H04S 2420/07 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04S 5/00 Pseudo-stereo systems, e.g. in which additional channel signals are derived from monophonic signals by means of phase shifting, time delay or reverberation

Abstract

A sound system comprises at least three audio driver arrangements (101, 103, 105) for emitting audio signals. The audio driver arrangements (101, 103, 105) are angled relative to each other to emit sound signals in different directions angled at least 45° apart. A driving unit (201, 203, 205) is provided for each audio driver arrangement (101, 103, 105) to generate a drive signal. The audio driver arrangements (103, 105) angled most relative to each other are arranged to emit audio signals being between 90° and 270° out of phase. The driving arrangement (201) for the third audio driver arrangement (101) has a varying phase response with a variation resulting in the emitted audio signal varying between a first phase interval proximal the signal emitted from a first of the other audio driver arrangements (103) and a second phase interval proximal to the signal emitted from the second of the other audio driver arrangements (105). The invention may e.g. allow a reduced sensitivity to speaker and listening positions.

Claims

1. A sound system for producing sound comprising:

a first audio driver arrangement (101) for emitting a first audio signal and having a first on-axis direction (111);

a second audio driver arrangement (103) for emitting a second audio signal and having a second on-axis direction (113), an angle between the first on-axis direction (111) and the second on-axis direction (113) being higher than 90°

;

a third audio driver arrangement (105) for emitting a third audio signal and having a third on-axis direction (109);

an angle between the first on-axis direction (111) and the third on-axis direction (109) being higher than 45° and

an angle between the second on-axis direction (111) and the third on-axis direction (109) being higher than 45°

;

a first driving arrangement (201) for generating a first drive signal for the first audio driver arrangement (101) from a first signal, the first driving arrangement (201) and the first audio driver arrangement (101) together having a first phase response;

a second driving arrangement (203) for generating a second drive signal for the second audio driver arrangement (103) from a second signal, the second driving arrangement (203) and the second audio driver arrangement (103) together having a second phase response; and

a third driving arrangement (205) for generating a third drive signal for the third audio driver arrangement (105) from a second signal, the third driving arrangement (205) and the third audio driver arrangement (105) together having a third phase response and the first signal, the second signal and the third signal comprising at least one common signal component;

wherein the first phase response deviates from the second phase response by between 90° and

270°

in a frequency interval above a first frequency; and

the third phase response is a varying phase response with a variation between a first phase interval proximal to the first phase response and a second phase interval proximal to the second phase response.

2. The sound system of claim 1 wherein the phase variation comprises a frequency domain variation in the frequency interval.

3. The sound system of claim 2 wherein the third phase response is within the first phase interval in at least a first frequency subinterval of the frequency interval and within the second phase interval in at least a second frequency subinterval of the frequency interval.

4. The sound system of claim 2 wherein the third phase response has a minimum of two transitions between the first phase interval and the second phase interval within the frequency interval.

5. The sound system of claim 2 wherein the third phase response has a maximum of six transitions between the first phase interval and the second phase interval within the frequency interval.

6. The sound system of claim 2 wherein the third driving arrangement (205) comprises at least one all-pass filter having a frequency varying phase response.

7. The sound system of claim 1 wherein the phase variation comprises a time domain variation.

8. The sound system of claim 1 further comprising means for generating the first signal from only a first signal of a stereo signal, the second signal from only a second signal of the stereo signal, and the third signal from both the first and second signal of the stereo signal.

9. The sound system of claim 1 wherein the first phase response and the second phase response are such that common signal components of the first audio signal and the second audio signal are substantially out of phase.

10. The sound system of claim 1 wherein a difference between the first phase response and the second phase response is below 45°

for frequencies below a second frequency, the second frequency being lower than the first frequency.

11. The sound system of claim 10 wherein a difference between the first phase response and the third phase response is below 45°

for frequencies below the second frequency.

12. The sound system of claim 1 wherein a gain response of at least one of the first driving arrangement (201) and the second driving arrangement (203) comprises an increasing gain for increasing frequency in at least one frequency interval above a frequency of 2 kHz.

13. The sound system of claim 1 wherein at least one of the first audio driver arrangement (101) and the second audio driver arrangement (103) comprises a plurality of driver units.

14. The sound system of claim 1 wherein at the third audio driver arrangement (105) comprises a plurality of driver units.

15. A method of operation for sound system for producing sound, the method comprising:

a first audio driver arrangement (101) emitting a first audio signal and having a first on-axis direction (111);

a second audio driver arrangement (103) emitting a second audio signal and having a second on-axis direction (113), an angle between the first on-axis direction (111) and the second on-axis direction (113) being higher than 90°

;

a third audio driver arrangement (105) emitting a third audio signal and having a third on-axis direction (109);

an angle between the first on-axis direction (111) and the third on-axis direction (109) being higher than 45° and

an angle between the second on-axis direction (111) and the third on-axis direction (109) being higher than 45°

;

a first driving arrangement (201) generating a first drive signal for the first audio driver arrangement (101) from a first signal, the first driving arrangement (201) and the first audio driver arrangement (101) together having a first phase response;

a second driving arrangement (203) generating a second drive signal for the second audio driver arrangement (103) from a second signal, the second driving arrangement (203) and the second audio driver arrangement (103) together having a second phase response; and

a third driving arrangement (205) generating a third drive signal for the third audio driver arrangement (105) from a second signal, the third driving arrangement (205) and the third audio driver arrangement (105) together having a third phase response and the first signal, the second signal and the third signal comprising at least one common signal component;

wherein the first phase response deviates from the second phase response by between 90° and

270°

in a frequency interval above a first frequency; and

the third phase response is a varying phase response with a variation between a first phase interval proximal to the first phase response and a second phase interval proximal to the second phase response.