As several have mentioned, I'm running five M80s, two QS8s, and two EP600s. The Halos are capable of 400 watts at 4 ohms, so all speakers have at least the 400 watts available, and have been told the Halos are capable of more than the rated 400. I do run the system at what most consider loud, usually the level is at 100 db with peaks at 105 -110 bd. I have maxed out the amps a few times by mistake, and did not do a SPL level, but the sound still remained clear.
From my expieraince with the Outlaw 950/770 you will have no problem running as many as five M80s and two QS8s with the volume level set at -15 on the 950, which in my enviroment produced a 90 - 95 db level. How ever, I had problems when I started to run above the -15 level for more than 20 minutes, those levels caused the 770 into a thermal protector level, and the imboard amp(s) would shut down, and would take 20 to 30 minutes to reset.
In my opinion and expierance with the M80s, you should not need speakers larger than them, just give the M80s the power, and you should have the sound level you desire, They do produce a lot of base, but in my opinion a sub(s) is still needed. I have found with the twin 600s and the BFD, I now have a higher db listneing area with the Halos running at a lower volume, still to soon to tell, but I may not be running the system at the 0 volume level on the processor from now on. lol
