Siahwayne,
Perhaps the problem are the Peavey speakers. My opinion of Peavey speakers is that most are made for guitars and as such are loud, but are stringy sounding with little or no bass.
Last month I used a large Peavey set up that was already in place at a gig and it was a mistake. I couldn't believe that I was playing my same keyboard -- thought for a while that the keyboard had gone sour.
Just my opinion.
Regards,
Walt