MT-32 music with SB sound is working for me using DOSBox 0.74 with default config except midiconfig= to select MIDI I/O for the MT-32. I can hear Sheltem's intro speech and the in-game sfx like "kick door in" and cast magic actions.

Maybe the SB isn't detected, although I haven't seen any sensitivity to cycles, but try the default cycles just in case. Also, ensure that the Efx setting in the game's control panel is ON.

Now that you mention it I do get the Sheltem intro vocals but thats it. Once the actual game starts theres no more soundblaster support.

I just went back and played it and I don't think theres as much digitized sfx as I thought, I think its mostly instuments. I guess what I'm noticing is that the roland + SB combo doesn't have sfx for menu selections or for attack impacts, or even footsteps. Amongst other things this option just sounds a lot more barren than the pure SB.

Thanks for your help I guess it's working fine.

*EDIT : Seems like a really bad MT-32 implementation, the game specifies LAPC-I, is it perhaps that it doesn't work right with my Gen 1 MT-32?

The choice of midi module attached to the MPU401 interface has no impact on the Soundblaster. The game just sends data to the MPU401 interface; What's attached to it doesn't matter. You can have nothing plugged in, it wouldn't make a difference.

The issue must be elsewhere! Hope you find it...

Compared to an MT-32, the LAPC-I and CM-32L have additional patches that are mostly for sfx, so it's possible the game is using them. But typically you won't hear *nothing* when a game tries to use one of the sfx sounds on an MT-32, rather you hear some inappropriate instrument sound instead.

Do check the "force door" and casting magic actions, I hear SB audio for them.

I hear nothing when I cast magic and only 'Percusion Taiko' from the MT-32 when I kick a wall.

It seems like after the intro the SB is not used.

I heard a sound like wind blowing, but I guess it was the synth. Wikipedia has a list of MT-32 compatible games, and MM3 has a footnote that it uses the extra sfx of the CM models (LAPC-I is basically a CM-32L on a card).

So I guess when you pick Roland + Sound Blaster it only actually uses the Sound Blaster for Sheltem's intro speech and everything else is generated by the MT-32/LAPC-I/CM-32L.

Oh well, the music is fantastic on the MT-32 but the game is so devoid of life when missing all the sound effects that I guess I'll have to play it in pure sound blaster mode.

I don't suppose theres anyway to force it to use both all the time SB and MT-32?

Well you can play just with a Soundblaster? While the music won't be as nice, at least you will have sound effects.

It's similar to Monkey Island 2. Do you want great music but a somewhat "empty" game with little sound effects or can you live with worse music but at least you get all the effects.

Having a CM unit doesn't guarantee you that all effects will play. It's totally up to the game and in Monkey Island 2 even on a CM unit the game feels very empty at times.