Patent ID: 8428284

Claim:
A loudspeaker with passive directional control at low frequencies comprising an enclosure having a front, a back and sidewalls, a transducer mounted to the front of said enclosure, said transducer having a diaphragm for producing acoustic energy from an electrical audio signal, said acoustic energy being produced as front-waves and back-waves, an acoustic chamber in said enclosure behind said transducer for receiving back-waves produced by said transducer, at least one port opening in said enclosure through which acoustic energy in said acoustic chamber produced by said transducer can exit said enclosure, and an acoustic fill material that substantially fills the entirety of the internal acoustic chamber of said enclosure between the sidewalls thereof and that extends from about said transducer for a distance that substantially covers said at least one port opening, said acoustic fill material having a low pass, low loss transfer function, wherein back-waves introduced into said acoustic chamber by said transducer experience delay at low frequencies with minimal attenuation before they exit said enclosure through said at least one port opening.