Why there are 4 connecting wires?

The Manger® sound transducer works with two voice coils which are electrically connected in parallel. These 2 coils lie adjacent to one another on a supporting frame. When one moves out of the air gap, an undesirable opposing force appears as a result of counter induction. This impairs the actual coil movement. However, as the second voice coil simultaneously moves into the magnetic field, the energy forces are neutralised and the opposing force is cancelled out. The voice coil is only moved time correctly by the music signal.
Using the patented twin voice coil principle, the Manger sound transducer achieves an extrememly fast rise time of 13µs. For lower frequencies i.e. with slower movements, these two adjacent coils act as one long voice coil and achieve a maximum excursion of +/-3.5mm.