Steinberg MR CSX review. A Cubase-friendly audio interface that comes with its own DSP. £; $ By Computer Music October Find great deals for Steinberg MR CSX Digital Recording Interface. Shop with Steinberg MR X, DSP StudioDigital Recording Innovative Cubase Integration Plus DSP Reverb! The Steinberg MR X is an innovative in/out FireWire interface, though it delivers much more than just.