I took the task of trying to mimick the YM2612 specs on my Yamaha DX7, and programmed patches that, within the spec of the 2612, make the E1M1 sound awesome...
Now I have no idea how I'd go about the percussions, so that was just software drumsets.. I used a total of THREE FM channels, 4 operators each..
(I'm fairly sure you can do tremolo on YM2612, so I did that for the right channel lead, just for effect)..
SO much better than what the Doom 32X shipped with, and I probably used less FM channels than they did too..
I'd be happy to share the FM matrix I used for the leads and bass if anyones interested.
Give me a map in Doom and I'll reproduce it in FM properly with 2612 limits..