Speaker system

Claim 1

A speaker system, comprising: a closed type cabinet in which a rear space relative to a speaker disposed face is closed; a plurality of double-voice-coil speaker units, each having a first voice coil and a second voice coil and being fixed to said closed type cabinet, each said first voice coil and second voice coil having a connection of a first polarity and a connection of a second polarity; and an impedance compensating circuit that makes the impedance of said speaker system constant; wherein the first voice coils of said plurality of double-voice-coil speaker units are connected in parallel to each other so that the respective same polarities are connected to each other, the second voice coils of said plurality of double-voice-coil speaker units are connected in parallel to each other so that the respective same polarities are connected to each other, an input signal is directly applied to said first voice coils of said plurality of double-voice-coil speaker units, and the input signal is applied to said second voice coils of said plurality of double-voice-coil speaker units through said impedance compensating circuit, said impedance compensating circuit is made up of a series circuit that includes an inductor and a capacitor, and said double-voice-coil speaker units are designed so that a resistance R v2 of said second voice coils and element constants L, C of said impedance compensating circuit satisfy the following expressions, under the condition that said second voice coils are opened, assuming that a resonance angular frequency is ω o , an equivalent mass is m o , a mechanical sharpness is Q m , a ratio of the force factor of said second voice coil to said first voice coil is α, an air compliance due to a volume within said closed type cabinet viewed from a single unit as disposed is C b , a mechanical resistance is r b , an inductance of said impedance compensating circuit is L, a capacitance of said impedance compensating circuit is C, the resistances of said first and second voice coils are R v1 and R v2 , respectively, and the number of said plurality double-voice-coil speaker units is n: R V2 = R V1  ( Q 0  Q m Q m - Q 0 )  { ( 1 Q 0 + n Q b ) - 2  α  ( Q m - Q 0 Q m  Q 0 ) } ; L = R V1 ω 0  ( Q 0  Q m Q m - Q 0 ) ; and C = 1 R V1  ω 0  ( Q m - Q 0 Q 0  Q m )  γ b n + γ b , where γ b = C b C 0   Q b = ω 0  m 0 r b .