I dont know the whole story to the config (I dont look at the z1r thread or anything), but the z1r does have great treble extension, perhaps a little too peaky which is what's causing the splashiness. Something has to be done to the mids as well - it's arguably the biggest flaw of the Z1R. Z2R soon?
Funny driver config never the less, one would assume the BA would be for mid, since thats how most hybrids are set up. It's more like a DD iem than a hybrid compare to other hybrid iems, and Its tuned kind of like a better sounding CE5. I'm not too mad about the mid, but I thought it would have better resolution.