This will not work (or at least, it is not worth the effort). The DSP amplifier is a very high-end, complex design and integrates through computer communications with multiple components in the car (MID, radio, phone, etc.). The amp is totally different from any aftermarket radio architecture. When the BMW radio detects a DSP amplifier, it completely changes its behavior. The radio actually becomes a "dumb" device and sends a two-channel, full volume line level signal to the DSP amp. The DSP amp is the thing that does all of the volume, balance, fader, equalization, etc. changes. These are a few of the major barriers that you would encounter.
- The DSP amp requires balanced audio inputs
- The DSP amp expects full-signal, line level inputs (with no volume, balance, fader, etc. modifications)
- The DSP amp must communicate with the head unit controlling it through the I-Bus