Abstract: A hearing normalization and correction system and process provides accurate correction for users with mild to moderate hearing loss by using actual measured hearing response at multiple sound pressure levels. User measured hearing data is collected at considerably higher resolution and accuracy at multiple sound pressure levels and is automatically converted to multiple accurate correction responses. Dynamic adaptive cross-fade response correction is used to deliver hearing normalization at varying sound pressure levels. Adaptive release response allows the hearing normalization system to accurately track the envelope of the incoming audio signal providing greatly enhanced accuracy and transparency. Adaptive headroom control is also applied to increase both input and output headroom providing professional dynamic range performance. The hearing normalization and correction system delivers audio fidelity and performance transcending that of normal hearing aid technology.

Abstract: An adaptive dynamic audio hum extractor eliminates line frequency hum components and associated higher harmonics from an audio signal. An audio signal containing line frequency hum can be processed by providing dynamically controlled notch filters at the fundamental line frequency and additional harmonic multiples of the fundamental frequency. The audio signal is detected to provide dynamic control of the depth of the notch filters. Alternatively, an audio signal containing hum can be processed by dividing the spectrum into at least two frequency bands, an unaltered high band combined with a dynamically processed low band. The adaptive dynamically controlled notch filters vary the depth of the notches in relation to the envelope or time averaged level of the bandwidth limited audio signal. This allows masking of the hum components with higher levels of audio, thereby providing transparency devoid of audio path notches.

Abstract: An adaptive dynamic audio hum extractor eliminates line frequency hum components and associated higher harmonics from an audio signal. An audio signal containing line frequency hum can be processed by providing dynamically controlled notch filters at the fundamental line frequency and additional harmonic multiples of the fundamental frequency. The audio signal is detected to provide dynamic control of the depth of the notch filters. Alternatively, an audio signal containing hum can be processed by dividing the spectrum into at least two frequency bands, an unaltered high band combined with a dynamically processed low band. The adaptive dynamically controlled notch filters vary the depth of the notches in relation to the envelope or time averaged level of the bandwidth limited audio signal. This allows masking of the hum components with higher levels of audio, thereby providing transparency devoid of audio path notches.

Abstract: For use in professional audio amplifier applications, high current charge pump circuits including charge circuits and dynamic release circuits are connected between respective storage capacitors and the audio power amplifier output. The charge circuits charge their storage capacitors when an output signal swing of the power amplifier is below a corresponding predetermined positive and negative threshold. The dynamic release circuits release power from their charged storage capacitors to dynamically vary the voltage levels of their positive and negative power supply rails in direct relation to the output signal swing of the power amplifier, preferably at unity gain. Multiple positive and negative power supply rails at different voltage levels can be used with cascaded multi-stage dynamic release circuits to maximize system efficiency. The charge and dynamic release circuits can be connected between their storage capacitors and a buffer amplifier which also receives the power amplifier audio input.

Abstract: For use in professional audio amplifier applications, high current charge pump circuits including charge circuits and dynamic release circuits are connected between respective storage capacitors and the audio power amplifier output. The charge circuits charge their storage capacitors when an output signal swing of the power amplifier is below a corresponding predetermined positive and negative threshold. The dynamic release circuits release power from their charged storage capacitors to dynamically vary the voltage levels of their positive and negative power supply rails in direct relation to the output signal swing of the power amplifier, preferably at unity gain. Multiple positive and negative power supply rails at different voltage levels can be used with cascaded multi-stage dynamic release circuits to maximize system efficiency. The charge and dynamic release circuits can be connected between their storage capacitors and a buffer amplifier which also receives the power amplifier audio input.

Abstract: For use in professional audio amplifier applications, high current charge pump circuits including charge circuits and dynamic release circuits are connected between respective storage capacitors and the audio power amplifier output. The charge circuits charge their storage capacitors when an output signal swing of the power amplifier is below a corresponding predetermined positive and negative threshold. The dynamic release circuits release power from their charged storage capacitors to dynamically vary the voltage levels of their positive and negative power supply rails in direct relation to the output signal swing of the power amplifier, preferably at unity gain. Multiple positive and negative power supply rails at different voltage levels can be used with cascaded multi-stage dynamic release circuits to maximize system efficiency. The charge and dynamic release circuits can be connected between their storage capacitors and a buffer amplifier which also receives the power amplifier audio input.

Abstract: Adaptive rail power amplifier technology processes an audio signal by feeding the audio signal to the power amplifier to produce an output signal, applying positive and negative power supply voltages centered with respect to the audio signal to the positive and negative power supply rails of the power amplifier, comparing the output signal with the positive and negative power supply rail voltages to produce dynamically varying positive and negative control signals, feeding the positive and negative control signals to positive and negative high current charge pumps and adding supplemental positive and negative voltages from the positive and negative charge pumps to the positive and negative power supply rails to produce a linear adaptive rail voltage which tracks the output signal.

Abstract: A multi-channel noise reduction system provides improved noise reduction with direct instrument tracking of all channels. In a two channel noise reduction system, both channels detect and track the input level and dynamic range of the guitar directly with one channel of dynamic noise reduction between the guitar and the input of a guitar amplifier to eliminate the noise of the instrument and another channel of noise reduction connected in the effects loop of the guitar amplifier. Multiple channels of noise reduction can be implemented with separated threshold controls and with low level expansion and dynamic filtering being combined so as to detect and track the input level and dynamic range of the guitar directly. A buffer amplifier can be used to feed the direct guitar signal to the detectors of the noise reduction system and the input of a stereo guitar system.

Abstract: A high definition distributed sound system has a master control hub with multiple serially linkable zones each capable of handling multiple serial arrays of powered speakers and a Cat5 cable. Each zone has an audio input, an internal master level controller and multiple powered-speaker outputs. Each of the serial arrays of powered speakers are connected to a corresponding powered-speaker output by the Cat5 cable. All of the zones can be used and controlled independently of the others or any number of them can be serially linked and controlled by their preceding zones. Additional master control hubs can be serially linked in a single system. The system interconnections can be done with Cat5 cable using RJ45 connectors. A low idle current power amplifier circuit offers extremely low levels of quiescent current, allowing a large number of speakers to be connected in one system.

Abstract: Adaptive rail power amplifier technology processes an audio signal by feeding the audio signal to the power amplifier to produce an output signal, applying positive and negative power supply voltages centered with respect to the audio signal to the positive and negative power supply rails of the power amplifier, comparing the output signal with the positive and negative power supply rail voltages to produce dynamically varying positive and negative control signals, feeding the positive and negative control signals to positive and negative high current charge pumps and adding supplemental positive and negative voltages from the positive and negative charge pumps to the positive and negative power supply rails to produce a linear adaptive rail voltage which tracks the output signal.

Abstract: Adaptive rail power amplifier technology processes an audio signal by feeding the audio signal to the power amplifier to produce an output signal, applying positive and negative power supply voltages centered with respect to the audio signal to the positive and negative power supply rails of the power amplifier, comparing the output signal with the positive and negative power supply rail voltages to produce dynamically varying positive and negative control signals, feeding the positive and negative control signals to positive and negative high current charge pumps and adding supplemental positive and negative voltages from the positive and negative charge pumps to the positive and negative power supply rails to produce a linear adaptive rail voltage which tracks the output signal.

Abstract: A multi-dimensional audio processor receives as an input either a single channel signal or a two channel signal from an audio signal source; for example a musical instrument or an audio mixer. The processor is programmable to divide the input among at least 3 output channels in a user-defined manner. The processor is also user programmable to provide a variety of effect and mixing functions for the output channel signals.

Abstract: A multi-channel noise reduction system provides improved noise reduction with direct instrument tracking of all channels. In a two channel noise reduction system, both channels detect and track the input level and dynamic range of the guitar directly with one channel of dynamic noise reduction between the guitar and the input of a guitar amplifier to eliminate the noise of the instrument and another channel of noise reduction connected in the effects loop of the guitar amplifier. Multiple channels of noise reduction can be implemented with separated threshold controls and with low level expansion and dynamic filtering being combined so as to detect and track the input level and dynamic range of the guitar directly. A buffer amplifier can be used to feed the direct guitar signal to the detectors of the noise reduction system and the input of a stereo guitar system.

Abstract: An input audio signal is detected to provide a fast time constant control signal which is clamped for immediate response when the input signal drops below a threshold level and filtered to provide a modified control signal with a slow time constant. As the modified control signal level decreases toward the control signal level, a time constant differential control signal decreases and slows the rate of change of the decreasing modified control signal which, as it nears the control signal level, reverts to a slow response. The resulting control signal has an exponential release response which can be applied to an audio dynamics processor. The time constant differential control signal may also be detected to provide an inverted output when it is significantly less than the modified control signal so as to result in the control signal also having an exponential attack response to be applied to the processor.

Abstract: An instrument amplification system provides improved low frequency enhancement. A powered subwoofer system enhances the low frequency components of a standard instrument amplifier by incorporating a speaker level high-pass filter crossover network 5 prior to connection to a standard instrument speaker. The speaker level instrument amplifier output is also attenuated, low-pass filtered and re-amplified to drive a dedicated low frequency subwoofer speaker. In one embodiment, a single speaker cabinet connects via a single speaker cable and includes both typical instrument speakers and an active powered subwoofer system. In another embodiment, a stand alone active powered 10 subwoofer connects to a standard instrument amplifier and includes a speaker level high-pass crossover output for connection to a standard instrument speaker cabinet. The instrument amplifier speaker output is attenuated, low-pass filtered, re-amplified and connected to a low frequency subwoofer speaker.

Abstract: An instrument amplification system provides improved low frequency enhancement. A powered subwoofer system enhances the low frequency components of a standard instrument amplifier by incorporating a speaker level high-pass filter crossover network prior to connection to a standard instrument speaker. The speaker level instrument amplifier output is also attenuated, low-pass filtered and re-amplified to drive a dedicated low frequency subwoofer speaker. In one embodiment, a single speaker cabinet connects via a single speaker cable and includes both typical instrument speakers and an active powered subwoofer system. In another embodiment, a stand alone active powered subwoofer connects to a standard instrument amplifier and includes a speaker level high-pass crossover output for connection to a standard instrument speaker cabinet. The instrument amplifier speaker output is attenuated, low-pass filtered, re-amplified and connected to a low frequency subwoofer speaker.

Abstract: Adaptive rail power amplifier technology processes an audio signal by feeding the audio signal to the power amplifier to produce an output signal, applying positive and negative power supply voltages centered with respect to the audio signal to the positive and negative power supply rails of the power amplifier, comparing the output signal with the positive and negative power supply rail voltages to produce dynamically varying positive and negative control signals, feeding the positive and negative control signals to positive and negative high current charge pumps and adding supplemental positive and negative voltages from the positive and negative charge pumps to the positive and negative power supply rails to produce a linear adaptive rail voltage which tracks the output signal.

Abstract: A multi-channel noise reduction system provides improved noise reduction with direct instrument tracking of all channels. In a two channel noise reduction system, both channels detect and track the input level and dynamic range of the guitar directly with one channel of dynamic noise reduction between the guitar and the input of a guitar amplifier to eliminate the noise of the instrument and another channel of noise reduction connected in the effects loop of the guitar amplifier. Multiple channels of noise reduction can be implemented with separated threshold controls and with low level expansion and dynamic filtering being combined so as to detect and track the input level and dynamic range of the guitar directly. A buffer amplifier can be used to feed the direct guitar signal to the detectors of the noise reduction system and the input of a stereo guitar system.

Abstract: A high definition distributed sound system has a master control hub with multiple serially linkable zones each capable of handling multiple serial arrays of powered speakers and a Cat5 cable. Each zone has an audio input, an internal master level controller and multiple powered-speaker outputs. Each of the serial arrays of powered speakers are connected to a corresponding powered-speaker output by the Cat5 cable. All of the zones can be used and controlled independently of the others or any number of them can be serially linked and controlled by their preceding zones. Additional master control hubs can be serially linked in a single system. The system interconnections can be done with Cat5 cable using RJ45 connectors. A low idle current power amplifier circuit offers extremely low levels of quiescent current, allowing a large number of speakers to be connected in one system.

Abstract: A multi-channel noise reduction system provides improved noise reduction with direct instrument tracking of all channels. In a two channel noise reduction system, both channels detect and track the input level and dynamic range of the guitar directly with one channel of dynamic noise reduction between the guitar and the input of a guitar amplifier to eliminate the noise of the instrument and another channel of noise reduction connected in the effects loop of the guitar amplifier. Multiple channels of noise reduction can be implemented with separated threshold controls and with low level expansion and dynamic filtering being combined so as to detect and track the input level and dynamic range of the guitar directly. A buffer amplifier can be used to feed the direct guitar signal to the detectors of the noise reduction system and the input of a stereo guitar system.