High fidelity sound reproducing system

A high fidelity sound reproducing system comprising:

• a dynamic speaker having a given operating frequency range and including a voice coil operatively driving a diaphragm;
• a differential power amplifier having an output coupled to the voice coil of said dynamic speaker and a noninverting input connected to an audio signal source for driving said speaker in accordance with an input audio signal;
• a measuring transducer associated with said dynamic speaker for generating a first feedback signal proportional to velocity of said dynamic speaker diaphragm;
• and
• an active differentiating signal amplifier having an input coupled to said measuring transducer for differentiating the first feedback signal over at least the operating frequency range into a second feedback signal proportional to acceleration of said dynamic speaker diaphragm, said active differential signal amplifier further having an output coupled to an inverting input of said differential power amplifier for feeding the second feedback signal thereto, thereby driving said speaker in accordance with the input audio signal and the second feedback signal,
• wherein said active differentiating signal amplifier exhibits a gain versus frequency characteristic which is substantially linear and proportional to frequency over a frequency range from about 10 Hz. to about 40,000 Hz.

A high fidelity sound reproducing system comprising:

• a dynamic speaker having a given operating frequency range and including a voice coil operatively driving a diaphragm;
• a differential power amplifier having an output coupled to the voice coil of said dynamic speaker and a noninverting input connected to an audio signal source for driving said speaker in accordance with an input audio signal;
• a measuring transducer associated with said dynamic speaker for generating a first feedback signal proportional to velocity of said dynamic speaker diaphragm;
• and
• an active differentiating signal amplifier having an input coupled to said measuring transducer for differentiating the first feedback signal over at least the operating frequency range into a second feedback signal proportional to acceleration of said dynamic speaker diaphragm, said active differential signal amplifier further having an output coupled to an inverting input of said differential power amplifier for feeding the second feedback signal thereto, thereby driving said speaker in accordance with the input audio signal and the second feedback signal, wherein said active differentiating signal amplifier imparts a phase shift of substantially 90.degree. to the second feedback signal with respect to the first feedback signal.

A high fidelity sound reproducing system comprising:

• a dynamic speaker having a given operating frequency range and including a voice coil operatively driving a diaphragm;
• a differential power amplifier having an output coupled to the voice coil of said dynamic speaker and a noninverting input connected to an audio signal source for driving said speaker in accordance with an input audio signal;
• a measuring transducer associated with said dynamic speaker for generating a first feedback signal proportional to velocity of said dynamic speaker diaphragm;
• and
• an active differentiating signal amplifier having an input coupled to said measuring transducer for differentiating the first feedback signal over at least the operating frequency range into a second feedback signal proportional to acceleration of said dynamic speaker diaphragm, said active differential signal amplifier further having an output coupled to an inverting input of said differential power amplifier for feeding the second feedback signal thereto, thereby driving said speaker in accordance with the input audio signal and the second feedback signal, wherein attenuation of the second feedback signal with respect to said differential power amplifier output signal is substantially constant over a frequency range from about 10 Hz. to about 40,000 Hz.

A high fidelity sound reproducing system comprising:

• a dynamic speaker having a given operating frequency range and including a voice coil operatively driving a diaphragm;
• a differential power amplifier having an output coupled to the voice coil of said dynamic speaker and a noninverting input connected to an audio signal source for driving said speaker in accordance with an input audio signal;
• a measuring transducer associated with said dynamic speaker for generating a first feedback signal proportional to velocity of said dynamic speaker diaphragm;
• and
• an active differentiating signal amplifier having an input coupled to said measuring transducer for differentiating the first feedback signal over at least the operating frequency range into a second feedback signal proportional to acceleration of said dynamic speaker diaphragm, said active differential signal amplifier further having an output coupled to an inverting input of said differential power amplifier for feeding the second feedback signal thereto, thereby driving said speaker in accordance with the input audio signal and the second feedback signal, including a voltage divider connected at the output of said active differentiating signal amplifier to attenuate the second feedback signal so that the level of the second feedback signal applied at the inverting input of said differential power amplifier is substantially the same as the level for the input audio signal applied at the noninverting input of said differential power amplifier over a frequency range from about 10 Hz. to about 40,000 Hz.

A high fidelity sound reproducing system comprising:

• a dynamic speaker having a given operating frequency range and including a voice coil operatively driving a diaphragm;
• a differential power amplifier having an output coupled to the voice coil of said dynamic speaker and a noninverting input connected to an audio signal source for driving said speaker in accordance with an input audio signal;
• a measuring transducer associated with said dynamic speaker for generating a first feedback signal proportional to velocity of said dynamic speaker diaphragm;
• and
• an active differentiating signal amplifier having an input coupled to said measuring transducer for differentiating the first feedback signal over at least the operating frequency range into a second feedback signal proportion to acceleration of said dynamic speaker diaphragm, said active differential signal amplifier further having an output coupled to an inverting input of said differential power amplifier for feeding the second feedback signal thereto, thereby driving said speaker in accordance with the input audio signal and the second feedback signal, including a high value resistor connected from the output of said differential power amplifier to its inverting input to provide stability for said differential power amplifier.

A high fidelity sound reproducing system comprising:

• a dynamic speaker having a given operating frequency range and including a voice coil operatively driving a diaphragm;
• a differential power amplifier having an output coupled to the voice coil of said dynamic speaker and a noninverting input connected to an audio signal source for driving said speaker in accordance with an input audio signal;
• a measuring transducer associated with said dynamic speaker for generating a first feedback signal proportional to velocity of said dynamic speaker diaphragm;
• and
• an active differentiating signal amplifier having an input coupled to said measuring transducer for differentiating the first feedback signal over at least the operating frequency range into a second feedback signal proportional to acceleration of said dynamic speaker diaphragm, said active differential signal amplifier further having an output coupled to an inverting input of said differential power amplifier for feeding the second feedback signal thereto, thereby driving said speaker in accordance with the input audio signal and the second feedback signal, wherein closed loop voltage gain of said differential power amplifier measured form the noninverting input to output is substantially constant over a frequency range from about 10 Hz. to about 40,000 Hz.

A high fidelity sound reproducing system comprising:

• a dynamic speaker having a given operating frequency range and including a voice coil operatively driving a diaphragm;
• a differential power amplifier having an output coupled to the voice coil of said dynamic speaker and a noninverting input connected to an audio signal source for driving said speaker in accordance with an input audio signal;
• a measuring transducer associated with said dynamic speaker for generating a first feedback signal proportional to velocity of said dynamic speaker diaphragm;
• and
• an active differentiating signal amplifier having an input coupled to said measuring transducer for differentiating the first feedback signal over at least the operating frequency range into a second feedback signal proportional to acceleration of said dynamic speaker diaphragm, said active differential signal amplifier further having an output coupled to an inverting input of said differential power amplifier for feeding the second feedback signal thereto, thereby driving said speaker in accordance with the input audio signal and the second feedback signal, wherein said measuring transducer is positioned in front of said diaphragm.

A high fidelity sound reproducing system comprising:

• a dynamic speaker having a given operating frequency range and including a voice coil operatively driving a diaphragm;
• a differential power amplifier having an output coupled to the voice coil of said dynamic speaker and a noninverting input connected to an audio signal source for driving said speaker in accordance with an input audio signal;
• a measuring transducer associated with said dynamic speaker for generating a first feedback signal proportional to velocity of said dynamic speaker diaphragm;
• and
• active signal processing means, having an input coupled to said measuring transducer, for phase shifting the first feedback signal by substantially 90.degree. over the operating frequency range and providing a frequency response proportional to frequency to provide a processed feedback signal, said active signal processing means having an output coupled to an inverting input of said differential power amplifier for feeding the processed feedback signal thereto thereby establishing the output signal driving said speaker in accordance with the input audio signal and the processed feedback signal from said active signal processing means.

A high fidelity stereo sound reproducing system having two channels, each of said channels including:

• a respective dynamic speaker having a given operating frequency range and including a respective voice coil operatively driving a respective diaphragm;
• a respective differential power amplifier having an output coupled to said respective voice coil of said respective dynamic speaker and a respective noninverting input connected to a respective audio signal source in a respective one of said channels for driving said respective speaker in accordance with a respective input audio signal;
• a respective measuring transducer associated with said respective dynamic speaker for generating a respective first feedback signal proportional to velocity of said respective dynamic speaker diaphragm;
• and
• a respective active signal processing means, having an input coupled to said respective measuring transducer, for phase shifting the respective first feedback signal by substantially 90.degree. over the operating frequency range and providing a frequency response proportional to frequency to provide a respective processed feedback signal, said respective active signal processing means further having a respective output coupled to an inverting input of said respective differential power amplifier for feeding the respective processed feedback signal thereto thereby establishing the output signal driving said respective speaker in accordance with the respective input audio signal and the respective processed feedback signal from said respective active signal processing means.