Mundorf Zero Ohm Coil (ZOC) chokes are transformer-format coils. These are made of Feron, a high quality material that minimizes induced distortions.

In these Zero Ohm Coil, the central space is calibrated and adjusted between the two laminar nuclei: one in the shape of an L and the other in the shape of an E. The volume of the central space determines the inductance of the coil and requires great care in the manufacturing process. It should not be too small, in which case saturation effects could occur at high load.

These coils are recommended for filtering bass speakers. Their low impedance improves impulse response for a loudspeaker with better handling.