JBLs are probably a lot more sensitive than M80s (which are pretty sensitive), but you may need to get an external amp if you want a lot more volume.

Remember that receiver volume displays are completely arbitrary--your might top out at +15dB, his at 0dB or something completely different.

I'll let someone else answer the Audyssy question; I have a Harman/Kardon.

Also, what actual decibel level are you reaching? Do you have a sound meter?

I am the Doctor, and THIS... is my SPOON!