| 摘要 |
PROBLEM TO BE SOLVED: To flatten frequency characteristics while eliminating a low-order resonance mode and eliminating the disturbance of frequency by providing a driving circuit for changing the arrival time of signals to be inputted to respective voice coils so as to have differences at the respective coils. SOLUTION: A delay circuit 6 is inserted on the preceding step of 2nd voice coil 4-2 among three voice coils 4-1 to 4-3 at a speaker unit S. Then, an output from an amplifier 5 is radiated from the speaker unit S while putting together signals timewisely delayed by this delay circuit 6 and output signals kept as it is. Thus, since the delay circuit 6 is arranged at one or all the voice coils among the plural voice coils of multipoint driven speaker or a phase circuit is arranged at one or all the voice coils among the plural voice coils 4, the low-order resonance mode is eliminated, the disturbance of frequency is eliminated and a reciprocating area is widened so that flat frequency characteristics can be provided. |
