Thanks for all the info. I noticed that the vp-150 is 6 ohms and the qs-8 is 8 ohms. Since I'm considering getting those with the m80s, does it matter to the receiver that they are all different? I assume not since I haven't read about any real issues regarding this. I also assume that lots of people with axiom HT systems have receivers like mine and have no issues. Thanks again.
The different impedance rating of 4, 6 or 8 ohms doesn't mean much. Despite each speakers rated impedance rating, if you look at the impedance graph of any speaker the impedance varies which each frequency. Impedance is not constant. So different impedance ratings will not harm anything.
The only harm impedance can cause is when a speakers impedance minimum is very low in the 2-4 ohm range in a limited range of frequencies (usually below 400hz) and where the phase angle is drawing current above what the impedance is at that frequency. At loud volumes and dynamic content, this might cause current limiting and overheating with some receivers.
That's not the case for the QS8's and VP150.
