Method and system for dynamically maintaining audio balance in a stereo audio system

• US 6,118,880 A
• Filed: 05/18/1998
• Issued: 09/12/2000
• Est. Priority Date: 05/18/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kokkosoulis, George, Temple, Daniel Anthony
• Primary Examiner(s): Lee, Ping
• Application Number:
  US09/080,810
• Time in Patent Office: 848 Days
• Field of Search: 381/303, 381/103, 381/315, 381/101, 381/102, 381/104, 381/105, 381/1
• US Class Current: 381/303
• CPC Class Codes: H04S 7/302 Electronic adaptation of stereophonic sound system to listener position or orientation H04S7/301 takes precedence
• CPC Class Codes: H04S 7/303 Tracking of listener position or orientation

Abstract

A method and system for dynamically maintaining audio output balance in a stereo audio system are disclosed. The stereo audio system includes a small hand-held radio frequency remote control and a set of transmitter/receiver control units located at a close proximity to a respective speaker. For example, the stereo audio system may have six transmitter/receiver control units: one at a front-left speaker, one at a front-right speaker, one at a rear-left speaker, one at a rear-right speaker, a center speaker, and a sub-woofer. The stereo audio system is able to make audio balance adjustment for simulating a stereo headphone effect based on the physical position of the listener, throughout the entire listening area.

Claims

1. A method for dynamically maintaining audio output balance in a stereo audio system, wherein said stereo audio system includes a base unit and at least four speakers, said method comprising the steps of:

coupling a first control unit between a first of said at least four speakers and said base unit;

coupling a second control unit between a second of said at least four speakers and said base unit;

coupling a third control unit between a third of said at least four speakers and said base unit;

coupling a fourth control unit between a fourth of said at least four speakers and said base unit, wherein each of said control units is positioned in close proximity to each of said respective speakers;

indicating a physical position of a listener with respect to all of said control units via a remote control;

determining a relative distance of said remote control with respect to each of said control units; and

adjusting audio output of each of said plurality of speakers by adjusting a value of a variable resistor within each of said control units, wherein said value of said variable resistor within each of said control units, R_s, is adjusted as follows;

for said first control unit, ##EQU5## for said second control unit, ##EQU6## for said third control unit, ##EQU7## for said fourth control unit, ##EQU8## where t₁ is a cumulative flight time between said first control unit and said remote control, t₂ is a cumulative flight time between said second control unit and said remote control, t₃ is a cumulative flight time between said third control unit and said remote control, and t₄ is a cumulative flight time between said fourth control unit and said remote control, so that true stereo balance audio is obtained at said physical position.

2. The method according to claim 1, wherein said indicating step is performed by sending radio frequency signals.

3. The method according to claim 1, wherein said determining step is performing by measuring a time required for transmitting a signal back and forth between said remote control and each of said control units.

4. A stereo audio system capable of dynamically maintaining audio output balance, wherein said stereo audio system includes a base unit and at least four speakers, said stereo audio system comprising:

a first control unit coupled between a first of said at least four speakers and said base unit, a second control unit coupled between a second of said at least four speakers and said base unit, a third control unit coupled between a third of said at least four speakers and said base unit, and a fourth control unit coupled between a fourth of said at least four speakers and said base unit, wherein each of said control units is positioned in close proximity to each of said respective speakers;

a remote control for indicating a physical position of a listener with respect to all of said control units;

means for determining a relative distance of said remote control with respect to each of said control units; and

means for adjusting audio output of each of said plurality of speakers by adjusting a value of a variable resistor within each of said control units, wherein said value of said variable resistor within each of said control units, R_s, is adjusted as follows;

for said first control unit, ##EQU9## for said second control unit, ##EQU10## for said third control unit, ##EQU11## for said fourth control unit, ##EQU12## where t₁ is a cumulative flight time between said first control unit and said remote control, t₂ is a cumulative flight time between said second control unit and said remote control, t₃ is a cumulative flight time between said third control unit and said remote control, and t₄ is a cumulative flight time between said fourth control unit and said remote control, so that true stereo balance audio is obtained at said physical position.

5. The audio system according to claim 4, wherein said remote control utilizes radio frequency signals to indicate a physical position of a listener with respect to all of said control units.

6. The audio system according to claim 4, wherein said determining means measures a time required for transmitting a signal back and forth between said remote control and each of said control units.

7. The audio system according to claim 4, wherein said adjusting means is a variable voltage divider.