Hi all. I've just purchased some B&W 686's (from superfi) and used them for about 10 hours now and loving them. However i've just been listening to some classical guitar and occasionally when a particular frequency catches one of the tweeters buzzes - only past a particular volume though. I assume that this is definately not part of the playing in process (!) and that it needs to go back for a replacement!? I've not noticed it with any other music. Should I just take them straight back!? Cheers, Matt