Spatial enhancement speaker systems and methods for spatially enhanced sound reproduction

• US 5,784,468 A
• Filed: 10/07/1996
• Issued: 07/21/1998
• Est. Priority Date: 10/07/1996
• Status: Expired due to Term

• Current Assignee: DTS LLC (Xperi Inc.)
• Original Assignee: SRS Labs Incorporated (Xperi Inc.)
• Inventors: Klayman, Arnold I.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): CHIN, VIVIAN C
• Application Number:
  US08/726,555
• Time in Patent Office: 652 Days
• Field of Search: 381/24, 381/17, 381/18, 381/63, 381/1
• US Class Current: 381/300
• 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 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

Abstract

Spatially enhanced sound is produced by vertically radiating a first sound from a left speaker by a first transducer. The first sound includes a sum component and a left difference component. A left difference sound is horizontally radiated from the left speaker by a second transducer. The left difference sound from the first transducer and the left component sound from the second transducer acoustically combine. A second sound is vertically radiated from a right speaker by a third transducer. The second sound includes a sum component and a right difference component. A right difference sound is horizontally radiated from the right speaker by a fourth transducer. The right difference sound from the third transducer and the right component sound from the fourth transducer acoustically combine and the sum component from the right speaker and the sum component from the left speaker acoustically combine.

Claims

1. A method for spatially enhanced sound reproduction in which audio speakers are located substantially at two locations whereas the sound experienced by a listener is perceived to emanate over a wide field and not from discrete locations, said method comprising the steps of:

radiating first sound waves having a sum component and a difference component so that said first sound waves are emanated from a generally vertical axis at a left-hand location;

radiating left difference sound waves so that said left difference sound waves are emanated from a generally horizontal axis at said left-hand location to acoustically combine with said first sound waves emanated from said vertical axis;

radiating second sound waves having a sum component and a difference component so that said second sound waves are emanated from a generally vertical axis at a right-hand location;

radiating right difference sound waves so that said right difference sound waves are emanated from a generally horizontal axis at said right-hand location to acoustically combine with said second sound waves emanated from said vertical axis.

2. The method for spatially enhanced sound reproduction as defined in claim 1, further comprising the steps:

receiving a stereo signal;

applying frequency compensation to an ambient component of said stereo signal; and

connecting said ambient component to at least one of said audio speakers.

3. The method for spatially enhanced sound reproduction as defined in claim 1, further comprising the steps of:

orienting said acoustically combined first sound waves and left difference sound waves towards a first ear of a listener; and

orienting said acoustically combined second sound waves and right difference sound waves towards a second ear of a listener.

4. A speaker system for reproducing spatially enhanced sound in which audio transducers are located substantially at a left-hand location and a right-hand location whereas the sound experienced by a listener is perceived to emanate over a wide field and not from discrete locations, said speaker system comprising:

a first transducer having a first sum plus difference input, said first transducer positioned at said left-hand location in a substantially vertical axis;

a second transducer having a left difference input, said second transducer positioned at said left-hand location in a substantially horizontal axis, so that sound emitted from said first transducer will acoustically combine with sound emitted from said second transducer when said first and second transducers are energized;

a third transducer having a second sum plus difference input, said first transducer positioned at said right-hand location in a substantially vertical axis; and

a fourth transducer having a right difference input, said fourth transducer positioned at said right-hand location in a substantially horizontal axis so that sound emitted from said third transducer will acoustically combine with sound emitted from said fourth transducer when said third and fourth transducers are energized.

5. The speaker system as defined in claim 4, wherein said first transducer is positioned above said second transducer and said third transducer is positioned above said fourth transducer.

6. The speaker system as defined in claim 4, said speaker system further comprising:

a first speaker housing, said first transducer and said second transducer mounted therein; and

a second speaker housing, said third transducer and said fourth transducer mounted therein.

7. The speaker system as defined in claim 4, further comprising:

a first chamber having a first volume, said first transducer mounted therein; and

a second chamber having a second volume, said second transducer mounted therein, wherein said first volume substantially equals said second volume.

8. The speaker system as defined in claim 4 further comprising a stereo source, said stereo source having a first output and a second output, said first output connected to at least said first transducer, and said second output connected to at least said third transducer.

9. The speaker system as defined in claim 4, said speaker system further comprising:

an audio signal source, said audio signal source having at least a first channel output and a second channel output; and

an audio processing system having at least a first processed output and a second processed output, said audio processing system configured to apply frequency correction to at least said first channel output and said second channel output, said first processed output connected to at least said first transducer, and said second processed output connected to at least said third transducer.

10. A method for spatially enhanced sound reproduction, comprising the steps of:

radiating a first sound from a left speaker in a horizontal direction from a first transducer, said first sound having a sum component and a left difference component;

radiating a left difference sound from said left speaker in a vertical direction from a second transducer, so that said left difference sound from said first transducer and said left component sound from said second transducer acoustically combine;

radiating a second sound from a right speaker, said second sound having a sum component and a right difference component, in a horizontal direction from a third transducer; and

radiating a right difference sound from said right speaker in a vertical direction from a fourth transducer so that said right difference sound from said third transducer and said right component sound from said fourth transducer acoustically combine and said sum component from said right speaker and said sum component from said left speaker acoustically combine.

11. The method for spatially enhanced sound reproduction as defined in claim 10, further comprising the steps of:

producing a first channel signal;

connecting said first channel signal to at least said first transducer;

deriving a first component of said first channel signal;

connecting said first component of said first channel signal to at least said second transducer;

producing a second channel signal;

connecting said second channel signal to at least said third transducer;

deriving a first component of said second channel signal; and

connecting said first component of said second channel signal to at least said fourth transducer.

12. A method of creating an improved acoustic sound field from a pair of speakers positioned about a listener, wherein said speakers reproduce sound derived from stereo audio signals, and wherein said stereo audio signals each comprise a monophonic component representing monaural sounds and a stereo component representing ambient sounds, said method comprising the following steps:

reproducing a first stereo signal through a first acoustic transducer of a first speaker, said first acoustic transducer of said first speaker having a central axis defining a general direction along which sound is projected by said first transducer;

reproducing a stereo component of said first stereo signal through a second acoustic transducer of said first speaker, said second acoustic transducer of said first speaker having a central axis defining a general direction along which sound is projected by said second transducer, wherein said central axis of said first transducer of said first speaker is substantially perpendicular to said second transducer;

reproducing a second stereo signal through a first acoustic transducer of a second speaker, said first acoustic transducer of said second speaker having a central axis defining a general direction along which sound is projected by said first transducer; and

reproducing a stereo component of said second stereo signal through a second acoustic transducer of said second speaker, said second acoustic transducer of said second speaker having a central axis defining a general direction along which sound is projected by said second transducer, wherein said central axis of said first transducer of said second speaker is substantially perpendicular to said second transducer.

13. The method of claim 12, wherein said first acoustic transducer and said second acoustic transducer are identical.

14. The method of claim 12, wherein said speakers are placed in a rear left-hand position and a rear right-hand position with respect to a listener.

15. The method of claim 12, wherein said first acoustic transducers of said first and second speakers are oriented towards a listener such that the corresponding central axes are substantially parallel with a floor of a room, and wherein said second acoustic transducers of said first and second speakers are horizontally oriented towards such that the corresponding central axes are substantially perpendicular to said floor of said room.