Yup, sure have to agree with you guys: had to walk away for a bit also with my M50s. I was actually paying attention due to having the same thing happen when I replaced an M3 I was using as center with a new M3 I had purchased to be the dedicated center.(I used one of the M3s I had as mains as a center for a while to see if I liked it-I did)The new M3 sounded a bit rough for a few minutes.

When I received the M50s and plunked them down where the M3s had been, they sounded decidedly "Worse" than the M3s! I don't believe it was all "Ears" as I was intentionally making a little test out of it due to it happening with the M3s.

The overall harshness left after about 20-24 minutes, and the bass came in all the way in about a week.(giving an honest appraisal on the bass is difficult due to the way the speakers are situated in(yuck!)cabinets, but they were disapointingly defecient in bass for quite a while)

I eventually did have to add some bass in the receiver to bring the bass to the level of my sub(which is kept at "is there a sub in the house?" levels) I cross them at 60hz.

But after a bit they went from "worse than" the M3s to actually "better" than the M3s in many respects!

Yup; they are sweet, aren't they!
Rich.