No clipping but with high volume i hear aggressive acute
It is also possible that the Tweeters get overloaded, then they start to glare (a kind of your aggressive acute). It isn't so uncommon, Tweeters aren't so robust than other chassis, that's one reason why some Manufacturers replace them with electrostatic (or similar) panels (see Verity Audio, Wilson Alexandria ...) when high volume is demanded.
Regular tweeters work very well until they reach their technical limit and then it is done, from one second to the next. You don't see them so often, because their price is higher for the manufacturer compared to conventional chassis (most are mass market units, a little bit modified for each manufacturer) :-)