Matt and Greg, welcome to Axiom. The M3 and M80 are each rated by Axiom with a sensitivity of 88dB for 1 watt at 1 meter. Don't think that bigger speaker means bigger amplifier, because enclosure size is related to tuning for low bass extension, but has no direct relation to sensitivity and power requirements.
At a typical listening distance of about 10' those speakers use 1 watt for a comfortably loud average listening level of about 83dB. Brief split second peaks on some dynamic source material require much more of course, and the 30 watts for which the 3020 is rated would allow for about a 98dB sound level. As always, the power requirement depends on speaker sensitivity, listening distance and how loud a level you use.
