Dynamic Power Sharing in a Multi-Channel Sound System

A signal processing system for use with an audio system having a plurality of audio channels, each channel having at least one amplifier and at least one electro-acoustic transducer, said electro-acoustic transducer of each channel being positionable relative to at least one other such transducer of the plurality of audio channels so as to enable perception, on the part of a listener positioned relative to said transducers, of a sonic presentation creatable by audio signals carried by said plurality of channels and reproducible in audible form by said transducers, including:

• at least one signal level threshold associated with at least one of said plurality of audio channels;
• a processor enabling manipulation of the audio signals in the channels, responsive to said at least one threshold, such that upon a signal in at least one channel reaching the said at least one threshold associated therewith, at least a portion of the audio signal in said at least one channel is routed to at least one other channel, and the signal in said at least one channel reaching the threshold is limited in conjunction with such routing so that said at least one channel does not overload and thereby introduce distortion due to overload;
• wherein in such manipulation a priority of preserving the fidelity of reproduction of the sonic presentation is first to the tonal distortion aspects and second to the spatial distortion aspects, and wherein first both tonal distortion and spatial distortion are minimized in said routing, but when signal power rises above a level where both tonal distortion and spatial distortion can be minimized staying within the total power handling of the system, spatial aspect distortion due to said manipulation is allowed in preference to allowing an increase in tonal aspect distortion due to overload, so that the sonic presentation perceived by a typical listener is preserved insofar as possible in such routing for the audio system within the power capability of the audio system.

A signal processing method for use with an audio system, comprising the steps of:

• increasing the apparent audio output of the audio system having a plurality of channels, each channel having at least one amplifier and at least one electro-acoustic transducer, said electro-acoustic transducer of each channel being positionable relative to at least one other such transducer of the plurality of audio channels so as to enable perception, on the part of a listener positioned relative to said transducers, of a sonic presentation creatable by audio signals carried by said plurality of channels and reproducible in audible form by said transducers, the sonic presentation having tonal aspects, and spatial aspects including sonic image and directional aspects, the audio system having a power capability of each channel of the system, and a total power handling capability of said plurality of channels combined;
• providing at least one signal level threshold associated with at least one of said plurality of audio channels;
• providing a processor enabling manipulating the audio signals in the channels, responsive to said at least one threshold,
• manipulating audio signals in a plurality of channels such that upon a signal in at least one channel exceeding the said at least one threshold associated therewith, at least a portion of the audio signal in said at least one channel is routed to at least one other channel;
• limiting the level of the signal remaining in, and reproduced in, said channel having a signal exceeding the threshold after said routing, so that tonal distortion of the signal reproduced in said channel due to overload is mitigated;
• mitigating distortion of the audio presentation in said manipulation by
• firstly preserving the tonal aspects of the audio image by minimizing tonal distortion, and
• subject to said firstly preserving the tonal aspects, secondly, preserving the spatial aspects of the audio presentation,
• configuring the processor so that in such manipulation preservation of the fidelity of reproduction of the sonic presentation is a priority while also enabling better utilization of the power capacity of at least one of:
• a) each channel of the plurality of channels, and b) the total power handling capability of the system.

A signal processing system configured for dynamic power sharing in a sound reproduction system having at least a first channel, a second channel and a third channel, each channel connectable to an audio transducer, and the system configured to enable creation of a sonic presentation including a) tonal aspects, and b) spatial aspects further including sound image and directional cue aspects, the third channel being a more robust channel over at least a portion of the frequency range of the audio signal in said third channel, said signal processing system including:

• signal processing, comprising at least one of circuitry and a microprocessor, the signal processing further including
• a signal path for the first channel and a threshold level associated therewith,
• a signal path for the second channel and a threshold level associated therewith, and
• a signal path for the third channel;
• said processing being configured to sense when an audio signal in one of the first and second channels exceeds a threshold level, and is configured to enable routing of at least a portion of said signal in excess of the threshold from at least said one of the said first and second channels of the system to the more robust third channel,
• at least one of tonal distortion and spatial distortion in the sonic presentation being reduced by said routing.

A signal processing system for use in a multi-channel audio system having a plurality of power amplifier channels connected to a plurality of loudspeakers and power amplifiers, configured to receive and reproduce audio signals through the loudspeakers, and at least a first channel of the plurality of power amplifier channels amplifying a first audio signal, comprising:

• a processor responsive to a signal level threshold applicable to at least said first channel, such that at and above the signal level threshold, the first audio signal in the first channel is amplitude limited and a portion of at least the first audio signal is mixed into at least a second channel,
• the amplitude limiting and signal mixing being configured so as to reduce introduction of at least one of:
• a) audible tonal distortion;
• and,
• b) perceivable spatial distortion,
• of a sonic presentation due to said limiting and signal mixing.

A method for increasing the perceived output of an audio system having a plurality of audio channels, including the steps of:

• providing a signal processor enabling manipulation of audio signals in said audio channels, each channel having at least one amplifier and at least one electro-acoustic transducer, said electro-acoustic transducer of each channel being positionable relative to at least one other such transducer of another channel of the plurality of audio channels so as to enable perception, on the part of a listener positioned relative to said transducers, of a sonic presentation creatable by audio signals which are carried by said plurality of channels and reproducible using said transducers, the sonic presentation having tonal distortion aspects, and spatial distortion aspects, including sonic image and directional aspects, the audio system having a power capability of each channel without introduction of audible distortion arising due to overload, and a total power capability of all the channels combined;
• setting at least one signal level threshold associated with at least one of said plurality of audio channels, the signal level threshold being just below that which would give rise to introduction of audible tonal distortion of an audio signal in said at least one channel due to overload;
• manipulating the audio signals in the channels, responsive to said at least one threshold, such that upon a signal in at least one channel reaching the said at least one threshold associated therewith, at least a portion of the audio signal in said at least one channel can be routed to at least one other channel, this step further comprising:
• limiting the signal in said at least one channel reaching the said at least one threshold associated therewith in such a way that audible tonal distortion due to overload in said at least one channel is mitigated;
• routing at least a portion of the audio signal in said at least one channel as needed to at least one other channel so that an unused portion of the total power capability of the system can be used to help reproduce said signal in said at least one channel when the power capability of said at least one channel is not enough to reproduce said signal therein without introduction of audible tonal distortion due to overload.

A method for increasing the perceived output of an audio system having a plurality of audio channels, including the steps of:

• providing a signal processor enabling manipulation of audio signals in said audio channels, each channel having at least one amplifier and at least one electro-acoustic transducer, said electro-acoustic transducer of each channel being positionable relative to at least one other such transducer of another channel of the plurality of audio channels so as to enable perception, on the part of a listener positioned relative to said transducers, of a sonic presentation creatable by audio signals which are carried by said plurality of channels and reproducible using said transducers, the sonic presentation having a) tonal aspects, including frequency and amplitude aspects, and b) spatial aspects, including sonic image and directional aspects, the audio system having a power capability of each channel without introduction of audible distortion due to overload and a total power capability of all the channels combined;
• setting at least one signal level threshold associated with at least one of said plurality of audio channels;
• enabling manipulating the audio signals in the channels, responsive to said at least one threshold, such that upon a signal in at least one channel reaching the said at least one threshold associated therewith, at least a portion of the audio signal in said at least one channel can be routed to at least one other channel, this step further comprising:
• limiting the signal in said at least one channel reaching the said at least one threshold associated therewith in such a way that audible tonal distortion due to overload in said at least one channel is mitigated;
• routing at least a portion of the audio signal in said at least one channel as needed to at least one other channel so that an unused portion of the total power capability of the system can be used to help reproduce said signal in said at least one channel when the power capability of said at least one channel is not enough to reproduce said signal therein without inducing audible tonal distortion due to overload;
• and,
• configuring the processor so that in such manipulation the preservation of the fidelity of reproduction of the sonic presentation perceivable by the listener is a priority.