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
When I bought my 702 s2, about 2 years ago now, I listened to a few different amps because I came across the same issue when researching the speaker before I bought it. Even though Rotel, I believe, is the same parent company as B&W, they do t seem to go well together. I use Anthem with the MCA class amp. It not nearly as “harsh” sounding. It is bit pricier but I like the company so far. That said I have some acoustic treatments as well. You may be getting a lot of high frequency echoing. Just an amateur audiophile my self but I like to research things 😬
I think Rotel, although good for the money, has a reputation to be bright.
Nope. I've never heard a bright Rotel through decent speakers.

The 705 series is a WTF as the B&W 80x series are superb.
My experience of Rotel with B&W was very positive. I have 805 D3s now and am happy with the highs. "watch me explode" is not particularly high. just to test, I played Renee Fleming, The Art of Renee Fleming, and the speakers handled the highs well. 
850cc

As a past owner of the 700 series the sibilants (s-sounds) are due to the midrange/crossover they use. There is a peak somewhere from 3-5k. I am sure the measurements show it. Not only is there a peak but it seems like cone break up as well. No electronics will fix it and if it really bothers you I would move to a different brand. 
I found the same issue with the 804d3. Only when moving to the 805s did it go away. Not sure about the 803d3 as I have not spend a lot of time with them, just demos. 
I own both Rotel and Macintosh amps. I can say the Rotel is brighter as a house sound. Is the Rotel bright or McIntosh dark? I don’t know but the McIntosh does soften the edges a bit and is more enjoyable. A change in amp will NOT fix the mids on the B&Ws though. 
 I'll throw in my two cents. I think everyone here would agree that trying to grade out a system at 50 hours is foolish. All new components, speakers, cables... need 2,3 or 4 times that much time to effectively burn in to produce their true sound. I run McIntosh gear with 805d3's and have zero brightness issues. As an example of my above statement, I just received a new Black Dragon USB cable yesterday (for another system) and just started burning it in today on my two channel system. This is the same USB cable I've been running for a couple of years and I love the sound. Well, immediately upon turning on the system with the new cable everything sounded thin (not bright) with no depth. It even affects the sound quality of the REL T7x subwoofer. If I didn't know (from past experience) things were going to drastically improve over the next 200 hours I'd be in panic mode myself. I'd recommend running in your system for a week or so 24/7 and then see where you are at. I'm sure it will be drastically better than where you are today. Good luck.