Bass reproduction speaker apparatus

A bass reproduction speaker apparatus, comprising:

• a cabinet with an opening, having a division member inside thereof, the division member dividing the cabinet into a front cavity and a back cavity;
• a first speaker unit disposed at the division member, the first speaker unit being placed inside the back cavity;
• a second speaker unit disposed in the opening, the second speaker unit being placed within the front cavity, the second speaker unit acting passively in response to the first speaker unit;
• an amplifying means for driving the first speaker unit;
• a first detection means for detecting a vibration of the first speaker unit;
• a first feedback means for feeding back an output signal from the first detection means to the amplifying means;
• a second detection means for detecting a vibration of the second speaker unit;
• and
• a second feedback means for feeding back an output signal from the second detection means to the amplifying means,
• wherein the first feedback means conducts both a velocity-type motion feedback and an acceleration-type motion feedback simultaneously over the same frequency band such that the acceleration-type motion feedback substantially aligns a height of peaks in an output sound pressure level versus frequency response of the speaker apparatus at two resonance frequencies in a low frequency range with each other, and the velocity-type motion feedback suppresses the peaks to obtain a substantially flat output sound pressure level over a wide range of low frequencies.

A bass reproduction speaker apparatus, comprising:

• a cabinet with an opening, having a division member inside thereof, the division member forming a closed space inside the cabinet;
• a speaker unit disposed at the division member, the back face of the speaker unit being disposed in the closed space;
• a port provided in the opening;
• an amplifying means for driving the speaker unit;
• a detection means for detecting a vibration of a moving system of the speaker unit;
• and
• a feedback means for feeding back an output signal from the detection means to the amplifying means, the feedback means conducting both a velocity-type motion feedback and an acceleration-type motion feedback simultaneously over the same frequency band such that the acceleration-type motion feedback substantially aligns a height of peaks in an output sound pressure level versus frequency response of the speaker apparatus at two resonance frequencies in a low frequency range with each other, and the velocity-type motion feedback suppresses the peaks to obtain a substantially flat output sound pressure level over a wide range of low frequencies.

A bass reproduction speaker apparatus, comprising:

• a speaker unit driven by an amplifier, the amplifier for driving the speaker unit as a function of a feedback signal;
• a detection means for detecting movement of the speaker unit as a result of the amplifier, and for producing the feedback signal as a function of the movement, wherein the detection means comprises a detector selected from a group consisting of a microphone, a piezoelectric sensor, a moving coil sensor, a light quantity detection sensor, a laser Doppler sensor, and an electrostatic sensor;
• and
• a feedback means for feeding back the feedback signal from the detection means to the amplifying means, the feedback means conducting both a velocity-type motion feedback and an acceleration-type motion feedback simultaneously over the same frequency band such that the acceleration-type motion feedback substantially aligns a height of peaks in an output sound pressure level versus frequency response of the speaker apparatus at two resonance frequencies in a low frequency range with each other, and the velocity-type motion feedback suppresses the peaks to obtain a substantially flat output sound pressure level over a wide range of low frequencies.

A bass reproduction speaker apparatus, comprising:

• a cabinet which has openings on respective opposing sides thereof and has division members inside thereof;
• passive radiators provided in the respective openings;
• a speaker unit disposed between the division members, the main axis of radiation of the speaker unit being perpendicular to the axes of radiation of the passive radiators;
• an amplifying means for driving the speaker unit;
• a detection means for detecting a vibration of a moving system of the speaker unit;
• and
• a feedback means for feeding back an output signal from the detection means to the amplifying means.