Josh,
The harshness you are detecting is due to the fact that you're sitting so close to the speakers. When I put my ear close to my M22's tweeter, for example, it sounds pretty harsh. The setup as it is now is less than ideal, as it seems you're beginning to realize.
Wall mounting the M2tis in oyur situation is a very good idea. In addition to being able to place them further apart, you'll be able to sit further away from them when listening. When you mount them, there are few things to take into consideration:
- The ideal height to mount them is with the tweeters at the same level as your ears when you're in your favorite listening position. If this is not possible or aesthetically pleasing, angle the speakers downward so the tweeters are firing downward toward your ears.
- Since the M2ti is a rear-ported speaker, you want to maintain a distance of a few inches from the wall.
Those are the basic guidelines and should yield good results. As far as how loud it is safe to go, your amp is rated at 75 watts/channel. It should be capable of driving your M2tis to painful levels in your room without damaging them.
