In an electromagnetic induction type speaker apparatus, individual constants
are
set in such a manner that the following formula is satisfied
where R1 is the DC resistance of a primary coil 15: L1 is
the inductance of the primary coil 15; N is the number of turns of the primary
coil 15; R2 is the DC resistance of the secondary coil 18;
L2 is the inductance of the secondary coil 18; and k is the coupling
coefficient of the primary coil 15 and the secondary coil 18.
In addition, the constants L1 and L2 are selected in such a manner
that the ratio of the inductance L1 and the inductance L2 becomes
equal to in the ratio of the DC resistance R1 and the DC resistance R2.
