NIDA Mk1 is supplied with a dedicated active crossover model X24. The crossover utilizes a filter with 24 dB/octave slopes and balanced inputs and outputs. Filter circuits utilize high precision resistors and polypropylene capacitors manually selected to the tolerance of +/- 0.2% in order to maintain symmetry of the channels and phase coherence.

Listeners who prefer to avoid using a preamplifier and who have only one source of sound signal, can order crossover X24A with built-in volume control.

Crossover X24 has a built-in sub-sonic filter which rejects sub-sonic signals originating from vinyl turntables. These filters can be disabled by an internal jumper, if so desired.