Luc, my thought would also be that QS4s would significantly increase your enjoyment. The 650 should have plenty of power for that room and there wouldn't appear to be a good reason to consider a separate pre-amp and amp.

As to speaker placement, if you don't have them with the M22 tweeters at ear level, or at least pointing to ear level, that's one suggestion. Separating them about as much as your distance from them, if possible, is another point.

-----------------------------------

Enjoy the music, not the equipment.