Directional tone color loudspeaker

• US 6,263,083 B1
• Filed: 04/11/1997
• Issued: 07/17/2001
• Est. Priority Date: 04/11/1997
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Weinreich, Gabriel
• Primary Examiner(s): Harvey, Minsun Oh
• Application Number:
  US08/837,297
• Time in Patent Office: 1,558 Days
• Field of Search: 381/300, 381/303, 381/304, 381/98, 381/99, 381/97, 381/160, 381/63
• US Class Current: 381/97
• CPC Class Codes: G10H 1/0091 Means for obtaining special acoustic effects combined with modulation G10H1/043
• CPC Class Codes: G10H 2210/301 Soundscape or sound field simulation, reproduction or control for musical purposes, e.g. surround or 3D sound; Granular synthesis
• CPC Class Codes: H04R 1/345 for loudspeakers

Abstract

The present invention simulates complex radiation patterns or directivity patterns of musical instruments, resulting in a surprising realism. The invention employs a plurality of sound sources disposed in close proximity to one another. The individual sound sources each provide a different signal delay resulting in constructive and destructive interference of the sound waves generated.

Claims

1. A Directional Tonal Color Loudspeaker for simulating a complex audio radiation pattern, comprising:

a plurality of electroacoustic transducers disposed in proximity to one another; and

a plurality of signal modification devices receiving an audio signal and producing a plurality of modified signals having varying phase delays, said plurality of modified signals provided to said plurality of electroacoustic transducers which generate a plurality of sound waves that constructively and destructively interact to simulate the angular radiation pattern of instruments;

wherein said signal modification devices produce said varying phase delays by delaying said sound waves relative to said audio signal by a plurality of different delay amounts, at least one of which delay amounts is less than twenty milliseconds.

2. The Directional Tone Color Loudspeaker of claim 1 further comprising attenuated feedback of said plurality of modified signals such that decaying reverberant signals are provided to said plurality of electroacoustic transducers which introduces additional complexity to said complex audio radiation pattern.

3. The Directional Tone Color Loudspeaker of claim 1 further comprising a low frequency transducer that is supplied said audio signal without delay.

4. The Directional Tone Color Loudspeaker of claim 3 wherein said audio signal is provided to a low pass filter for filtering prior to being supplied to said low frequency transducer.

5. The Directional Tone Color Loudspeaker of claim 1 wherein said audio signal is provided to a high pass filter for filtering prior to being modified by said plurality of modification devices.

6. The Directional Tone Color Loudspeaker of claim 1 wherein four electroacoustic transducers are disposed in close proximity to one another.

7. The Directional Tone Color Loudspeaker of claim 1 wherein five electroacoustic transducers are disposed in close proximity to one another.

8. The Directional Tone Color Loudspeaker of claim 1 wherein said complex audio radiation pattern is simulating sound originally produced by a single source.

9. The Directional Tone Color Loudspeaker of claim 1 wherein said complex audio radiation pattern is simulating sound originally produced by a sound source which generates different notes at different locations.

10. A method for simulating a complex audio radiation pattern, comprising the step of:

(a) receiving an audio signal;

(b) dividing said audio signal into a plurality of audio frequency bands;

(c) altering the phase of each of said plurality of audio frequency bands by delaying said audio frequency bands by a plurality of different delay amounts, at least one of which delay amounts is less than twenty milliseconds in order to produce a plurality of modified audio frequency bands; and

(d) generating a plurality of sound waves with said plurality of modified audio frequency bands using a plurality of audio sources disposed in close proximity to one another such that constructive and destructive interaction of said sound waves simulate the angular radiation pattern of instruments.

11. The method for simulating a complex audio radiation pattern of claim 10, further comprising the step attenuating said plurality of modified audio signals.

12. The method of simulating a complex audio radiation pattern of claim 10, further comprising the step of generating low frequency sounds with a low frequency transducer.

13. The method of simulating a complex audio radiation pattern of claim 10, further comprising the step of filtering the high frequency components of said audio signal.

14. The method of simulating a complex audio radiation pattern of claim 10, further comprising the step of filtering the low frequency components of said audio signal.

15. The method of simulating a complex audio radiation pattern of claim 10 wherein four audio sources are disposed in close proximity to one another.

16. The method of simulating a complex audio radiation pattern of claim 10 wherein five audio sources are disposed in close proximity to one another.

17. The method of simulating a complex audio radiation pattern of claim 10 wherein said complex audio radiation pattern is simulating sound originally produced by a single source.

18. The method of simulating a complex audio radiation pattern of claim 10 wherein said complex audio radiation pattern is simulating sound originally produced by a sound source which generates different notes at different locations.