Patent ID: 7130441

Claim:
An acoustic signal output apparatus comprising: a speaker unit comprising: a main converter having a first movable portion capable of moving along a predetermined axial line, said main converter for converting an electrical signal into mechanical vibration; a vibration plate attached to said first movable portion, said vibration plate for emitting sound waves to a front side of said main converter; and a frame fixed to said main converter, said frame vibratably supporting said vibration plate from a rear side of said vibration plate; a compensation converter for converting an electrical signal into mechanical vibration, said compensation converter being fixed to a rear side of said main converter and having a second movable portion capable of moving along the predetermined axial line; a compensation mass body attached to said second movable portion, said compensation mass body for serving as a load of mechanical vibration of said compensation converter; a signal source for generating an output signal corresponding to an acoustic signal to be outputted; and a signal processing circuit for receiving the output signal of said signal source, at least one of amplifying and attenuating the output signal, and supplying said main converter and said compensation converter with the respective electrical signals such that the said first movable portion and said second movable portion move in opposite directions at the same time, wherein said compensation converter is smaller and lighter than said main converter.