Method and apparatus for creating a virtual third channel in a two-channel apmlifier

• US 20040086128A1
• Filed: 11/01/2002
• Published: 05/06/2004
• Est. Priority Date: 11/01/2002
• Status: Active Grant

• Current Assignee: Peavey Electronics Corporation
• Original Assignee: Peavey Electronics Corporation
• Inventors: Risch, Jon M., Heath, Emmett E.
• Granted Patent: US 7,251,333 B2
• Time in Patent Office: Days
• US Class Current: 381/1
• CPC Class Codes: H04R 3/14 Cross-over networks
• CPC Class Codes: H04S 1/00 Two-channel systems H04S5/00, H04S7/00 take precedence

Abstract

A method and apparatus for creating a third signal channel from an input signal received in each of a first and second channel involves inverting a predetermined frequency range of signals in the first channel out of phase with a corresponding frequency range of signals in the second channel. Thereafter, the inverted signal in the first channel and the corresponding frequency signal in the second channel may be communicated to a speaker, which is bridged across the first and second channels, as the third signal channel. This speaker produces sound corresponding to the difference (i.e., the frequency range determined by the predetermined bandwidth of the inverted signal) between the inverted signal in the first channel and the corresponding frequency signal in the second channel.

Claims

1. A method for creating a third signal channel from an input signal received in each of a first and second channel, comprising the steps of:

shifting a predetermined frequency range of signals in the first channel out of phase with the input signal in the first channel;

inverting the shifted signal in the first channel to produce an inverted signal, wherein the predetermined frequency range of signals in the inverted signal in the first channel is out of phase with a corresponding frequency range of signals in the second channel; and

communicating the inverted signal in the first channel and the signal in the second channel to a third channel speaker as the third signal channel.

2. The method of claim 1, wherein the predetermined frequency range of signals include low frequency signals.

3. The method of claim 2, comprising the steps of:

communicating the inverted signal in the first channel to a first speaker and to a first input of the third channel speaker;

communicating the signal in the second channel to a second speaker and to a second input of the third channel speaker; and

wherein the differential signal of the inverted signal and the signal in the second channel are reproduced by the third channel speaker as low frequency sound.

4. The method of claim 1, wherein:

modifying the amplitude of the inverted signal for communication to a first speaker and to a first input of the third channel speaker; and

modifying the amplitude of the signal in the second channel for communication to a second speaker and to a second input of the third channel speaker.

5. The method of claim 1, wherein the third channel speaker is a subwoofer speaker.

6. An apparatus for creating a third channel signal from an input signal received in each of a first and second channel, comprising:

a filter configured to shift a predetermined frequency range of signals in the first channel out of phase with the input signal in the first channel;

an inverter configured to invert the shifted signal in the first channel to produce an inverted signal, wherein the predetermined frequency range of signals in the inverted signal in the first channel is out of phase with a corresponding frequency range of signals in the second channel; and

wherein the differential of the predetermined frequency range of signals in the inverted signal in the first channel and the corresponding frequency range of signals in the second channel comprise the third channel signal.

7. The apparatus of claim 6, further comprising:

a third channel speaker coupled to the third channel signal for producing sounds corresponding to differential of the predetermined frequency range of signals in the inverted signal in the first channel and the corresponding frequency range of signals in the second channel.

8. The apparatus of claim 6, wherein the predetermined frequency range of signals corresponds to low frequencies.

9. The apparatus of claim 6, further comprising:

a first amplifier configured to communicate the inverted signal to a first speaker and to a first input of a third channel speaker; and

a second amplifier configured to communicate the signal in the second to a second speaker and to a second input of the third channel speaker.

10. A method for creating a third channel from an input signal received in each of a first and second channel, comprising the steps of:

receiving an input signal in each of a first and second channel;

passing high frequency signals in each of the first and second channels;

summing the input signal in the first channel with the input signal in the second channel to produce a summed signal;

amplifying the summed signal in accordance with a predetermined gain;

passing low frequency signals in the summed signal;

combining the passed high frequencies in the first channel with the summed signal; and

inverting the summed signal in the second channel, wherein the low frequency signals in the second channel are out of phase with the low frequency signals in the first channel.

11. The method of claim 10, further comprising the steps of:

amplifying the combined signal in the first channel to produce a first channel output signal; and

amplifying the high frequencies in the second channel and the inverted summed signal to produce a second channel output signal.

12. The method of claim 11, further comprising the steps of:

communicating the first channel output signal to a first speaker and a first input on a third speaker; and

communicating the second channel output signal to a second speaker and to a second input on the third speaker, wherein the third speaker produces low frequency sounds in accordance with a differential between the first and second channel output signals communicated to the third speaker.

13. The method of claim 10, wherein the predetermined level of gain controls the amplitude of the low frequency signals communicated in the third channel.

14. The method of claim 10, further comprising the step of:

combining the passed high frequencies in the second channel with the inverted summed signal to produced a combined second channel signal.

15. The method of claim 14, further comprising the steps of:

amplifying the combined second channel signal to produce a first channel output signal; and

communicating the amplified combined second channel signal to a second speaker and to an input on the third speaker.

16. An apparatus for creating a third channel from an input signal received in each of a first and second channel, comprising:

a high pass filter to pass high frequency signals in each of the first and second channels;

a summing circuit configured to sum the input signal in the first channel with the input signal in the second channel, wherein the summing circuit produces summed signal;

a low pass filter configured to pass low frequency signals in the summed signal, wherein the low pass filter outputs a low frequency summed signal;

a first channel combining circuit configured to combine the high frequency signals in the first channel with the low frequency summed signal to produce a first channel output signal; and

a second channel combining circuit configured to combine the high frequency signals in the second channel with the low frequency summed signal to produce a second channel output signal, wherein the low frequency signals in the second channel output signal are out of phase with the low frequency signals in the first channel output signal.

17. The apparatus for claim 16, wherein the second channel combining circuit inverts the low frequency summed signal to produce the second channel output signal.

18. The apparatus for claim 16, further comprising:

an amplifier configured to modify the amplitude of the summed signal in accordance with a predetermined gain.

19. The apparatus for claim 16, further comprising:

a first channel amplifier configured to modify the amplitude of the first channel output signal, wherein the amplified first channel output signal is communicated to a first speaker and to the first input of a third speaker;

wherein the second channel combining circuit modifies the amplitude of the second channel output signal; and

wherein the second channel output signal is communicated to a second speaker and the second input of the third speaker.

20. The apparatus for claim 16, wherein the high pass filter, summing circuit, low pass filter, first and second channel combining circuits are contained in a first enclosure coupled to a first and second amplifiers configured to amplify the first and second channels, the first and second amplifiers contained in a second enclosure.