Abstract: The invention provides a speaker unit for low frequency reproduction wherein distortion is reduced and the orientation of a sound image of the lower side frequency region is augmented. To that end, the phase characteristic in an actually used frequency band is made substantially flat. The speaker unit includes a speaker enclosure, a duct formed in the speaker enclosure and having a port thereon, and a speaker mounted in the speaker enclosure. The speaker is formed such that it has a first resonance frequency set higher than a higher side frequency of the actually used frequency band (about 20 Hz to 100 Hz), while the port is formed such that it has a second resonance frequency set lower than a lower side frequency of the actually used frequency band.

Abstract: The invention provides a speaker unit for low frequency reproduction wherein distortion is reduced and the orientation of a sound image of the lower side frequency region is augmented. To that end, the phase characteristic in an actually used frequency band is made substantially flat. The speaker unit includes a speaker enclosure, a duct formed in the speaker enclosure and having a port thereon, and a speaker mounted in the speaker enclosure. The speaker is formed such that it has a first resonance frequency set higher than a higher side frequency of the actually used frequency band (about 20 Hz to 100 Hz), while the port is formed such that it has a second resonance frequency set lower than a lower side frequency of the actually used frequency band.

Abstract: The invention provides a speaker unit for low frequency reproduction wherein distortion is reduced and the orientation of a sound image of the lower side frequency region is augmented. To that end, the phase characteristic in an actually used frequency band is made substantially flat. The speaker unit includes a speaker enclosure, a duct formed in the speaker enclosure and having a port thereon, and a speaker mounted in the speaker enclosure. The speaker is formed such that it has a first resonance frequency set higher than a higher side frequency of the actually used frequency band (about 20 Hz to 100 Hz), while the port is formed such that it has a second resonance frequency set lower than a lower side frequency of the used frequency band.

Abstract: A sub-woofer system with a flat horn for use in a vehicle which is capable of achieving an improved sound reproducing performance as well as an excellent space factor by mounting the horn on the floor of the vehicle. The sub-woofer system includes a flat horn having a proximal end and a distal end where the proximal end is connected to a drive unit. The flat horn has a rectangular cross-section and is substantially uniform in thickness throughout while gradually increases in width toward the distal end. The drive unit is positioned under a front seat of the vehicle and the flat horn is placed on a floor of the vehicle, and wherein an end opening of the flat horn at the distal end thereof is positioned close to an inner front wall of the vehicle so that at least a part of the distal end contacts with the front wall.

Abstract: A sub-woofer system with a flat horn for use in a vehicle which is capable of achieving an improved sound reproducing performance as well as an excellent space factor by mounting the horn on the floor of the vehicle. The sub-woofer system includes a flat horn having a proximal end and a distal end where the proximal end is connected to the drive unit for guiding the sound produced by the drive unit. The flat horn is substantially uniform in thickness throughout while gradually increases in width toward the distal end. The drive unit is positioned under a front seat of the vehicle and the flat horn is placed on a floor of the vehicle, and wherein an end opening of the flat horn at the distal end thereof is positioned at a fire wall of the vehicle to exhaust the sound from the drive unit.