Well I used a small amount of moretite around the speaker baskets (made the mistake of sealing the entire baskets before and it sounded terrible) and used 1/4" thick acoustic felt around the tweeters and it's made a huge difference in sound. IMO these little M3's sound much more balanced this way, particularly in fast metal/rock music. I felt they were too boomy and loose with bass and the treble was a bit too bright compared to the mids (which were rather sterile sounding) I'm happy with the changes that these small modifications have made. These speakers are vibrant and sound organic and lively with folk/classical music but they sort of muddle rock music a bit.
