by wigworld » Thu Aug 02, 2007 8:10 pm
I think you would need to merge the two banks into one (page 52 in manual), then set up that merged bank to autoload on boot up (further down page 52). I can't confirm this works as I only have the esynth ROM by itself, but it should do the trick.
I've never come across any custom sound ROMs, but I understand the ROMs for the Emu Proteus synths will work to a limited degree in the EOS Ultra samplers - I believe they'll import sounds and keymaps, but not filter settings or modulation routings.