Here is my problem. I know the out put values on the amp @ 2ohm(115wrms) and 4ohm(75wrms),what I don't know is the output @ 3ohm which is waht my comps are.

Should I assume a midpoint? And effectivly gain down to say 85w(100wrms 3ways and 90wrms 2ways)meaning figure voltage for 85w @ 3ohms and set accordingly.

Or do I just need to get an o-scope and do it on a bench?

does the output voltage actually shift that much when going from 4 to 2ohms?

I doubt it but if it does.. that amp may not last too long.

And that will affect your ear how? No need to get every last drop out of any amp, in fact it is pretty much a bad idea and useless anyways as you won't hear it. Don't chase tenths when dB's allude you.

Yeah......found the formula I was looking for after I made the post. Looks like I pick up 1.7wats from 4 to 3ohms any way.

2V is a huge swing from 2ohm to 4ohm? I ask because I don't know. 15V@2ohm and 17V@4ohm.

Anyway backward calcs only show 76.7w @ 3ohm. So I'll just set it up for a 4ohm load.

Just don't want to over drive anythhing.