I cant move it much, I did move it out a bit and also put a small blanket double wrapped along the back of speaker didn't help enough..
I guess using a total different brand center is a no?
Some people have luck using different brand centers. I think it all depends on which brands you mix and match and how sensitive you are to tonal differences. If you already have another center laying around it wouldn’t hurt to try, but I wouldn’t go out and buy another brand center w/o the option to return it if it doesn’t work.
Is it going to be impossible for you to use a M22 speaker as a center? The reason I ask is when crossed over with a subwoofer it is a very close match for the M80s. As close as your going to get w/o using another M80. To get an idea of how this will sound set your center speaker to “none” in the receiver allowing you to use a “phantom” center with the 2 M80 mains. If you like the sound of this I think you’ll like the sound of the M22 as a center speaker. Fredk even uses two M2 speakers one above and one below his screen to good effect.
Also, as I mentioned the VP100 shouldn’t from what I’ve read (don’t have one myself) exhibit the effect your hearing.
I’m pretty sure that if you trade in a speaker within the 30 day demo period for another speaker Axiom foots the shipping for the return. I’m not 100% sure if that applies to trading in for a lesser price speaker but someone else can probably confirm it or not.