Basically you can assign each midi channel to the RM1x's tone generator, or an external midi device (i.e another synth, a sampler or anything that makes a noise really).
*You can also assign it to both at the same time which is a neat trick to enable you to get 32 midi channels instead of 16...

The reason why i sample the sounds, is because to create a decent sound on the RM1x you have to really cain the effects, filters... so the polyphony of the tone generator can be quickly used up on 2 or 3 tracks.
It is possible to do whole songs using just the RM1x which sound half decent, don't get me wrong !!!

If i sample the RM1x's sound then the tone generator on the RM1x is no longer being used as the sampler is then providing the sound. I have an A4K sampler which has much higher polyphony than the RM1x.

The sampler is simply controlled by midi note on/off messages in the RM1x's sequencer.
If you have a sound in the sampler you can assign it to the RM1x's keyboard (or your controller, i prefer) and then record in a pattern as normal.

The RM1x can also control effects,filters etc on any external equipment simply by assigning the correct controller change command.

I can't praise the thing enough, fairly simple to use and very very effective.

If you want to know anymore let me know, i'll not be back on this board till tomorrow.

Rich.