I just found out that I can change the impedence on my receiver from 8 ohms to 6 ohms. However, it only does one or the other, and I have a mix of speakers that have different impedences (the m60s and the qs8s). What is the difference between the output with 6 or 8 ohms, and is either way not good for the speakers?

Also, it has 120 watts per channel. Is it even possible for me to damage a set of m60s with that kind of rating?