B&W speakers sounding very harsh?


Hey guys, brand new here.

So I recently got a new sound system for my game room. Keep in mind as I'm explaining everything that I'm brand new to the world of sound systems and how they work.

Here's what I'm using: I have a Marantz SR7015, a pair of B&W 702 S2's that are being powered from a Rotel amp (can't remember the model) , 700 series center channel, 600 series rears (the anniversary edition) and the 1000w sub. I also have 4 overhead speakers that are no B&W's.

The system sounds amazing! .....except for one thing. The highs sound very harsh on certain songs. It's almost like I hear a crackling if that makes sense but even putting my ears up to the speakers I can't pinpoint it. A good example is T.N.T. by AC/DC, when I listen to this song it's almost like I can hear a buzzing or crackling coming from somewhere (watch me explooooooooooode!) and the highs of the song sound very grating. Again, I'm having difficulty pinpointing what it could be and I listen to some songs and they sound just fine.

Keep a few things in mind. A. The sound system is relatively new and the sound system has probably 60 total hours of play time. I've read that these systems do require break in time. I also started from scratch learning how to configure everything (it took me 2 days before I figured out how to get sound of the speakers turned on) so it's possible I may have the tweeters turned up too high.

Based on the limited info I was able to give, does anyone have any advice? TY!
vgundam21
Have your run the Room correction?  Audyssey often will help with those hard edges.  If you haven't run it, try that and see if it helps.  
To answer both questions, I ran the Marantz Audyssey setup which was a good start and I went from there. I did a little bit of tweaking after it was done (it turned my bass waaaaaaaaay down for example, with a 1000w sub I should be able to at least feel it a little bit) and have been trying to get it adjusted to my liking. It's set up as a 5.1.4 system, I realize doing both is not really efficient and my primary focus for it is movies but I do like to play my Spotify through it and listen to my music.