Patent ID: 7346315

Claim:
A handheld device loudspeaker system comprising: a first loudspeaker that emits a first acoustic wave that is substantially omnidirectional, said first loudspeaker being described by a first electric-to-acoustic signal transfer function for acoustic signals radiated in a first direction; a second loudspeaker that emits a second acoustic wave in the first direction and emits, in a second direction that is opposite the first direction, a third acoustic wave that is opposite in phase relative to the second acoustic wave, said second loudspeaker being described by a second electric-to-acoustic signal transfer function for acoustic signals radiated in the first direction; and one or more drive circuits coupled to the first loudspeaker, and the second loudspeaker, said one or more drive circuits comprising: a first signal processing circuit for performing one or more filter functions, wherein the one or more filter functions compensate for a difference between the first electric-to-acoustic signal transfer function, and the second electric-to-acoustic signal transfer function.