You will really need to get an editor for the XP-80 to do this, or actually do it for the instrument itself.
It may be possible to do it using non resistered parameter continous controller numbers, but it will driver you mad - I know I did it with a old Boss DS-330 GM module.

I would edit the synth directly (if you have no editting software) and get a balance your happy with. I tend to have the kick and snare sounds as high as they can go, and back off the cymbols (hi-hats included).
I would also adjust the reverb send levels while I'm at it, bring the levels right down on the kick drum, and cymbols, nothing worsh than reverb on kick - turns it into mush, unless you like that sort of thing.

Once your happy with you ideal rhythm kit SAVE IT.

You can use TeeJay's suggestion too, however you will not be able to use MIDI controller messages on each track as all will effect MIDI channel 10, but what you can do (and what I think he ment) because each drum part is on a seperate track you can add velocity or decrease to adjust the releative level.

Hope this helps.




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