Yeah SRP i am a pretty straight to the point person
In all honestly ,you should not need a sub with 2 channel music using he M80's unless you like organ music maybe. I mostly listen to classic rock and 80's an 90's music, my main speakers have 12in bass drivers and i recently added a sub just becasue i had an extra one. Honestly i am underwhelmed using the sub in a 2 channel system. For all intents and purposes, a sub is more suited to HT use for LFE effects. I understand most people have room constraints but the best method is the subcrawl. Put the sub where you usually sit and then crawl around the room until you hear the best response. This is where the sub should go if at all possible, at the very least put it there temporarily so you can see what is possible. Depending on the size of your room, you may not have a large enough sub to pressurize it properly. Bass waves are very long and they tend to come back on themselves causing a both boosts and drops in varying frequencies , this where some type of room correction software can come in handy if you dont want to add bass traps. Honestly you cant just buy a sub, dump it in the corner and expect a great result, for truly great results some effort and testing is required.
