I heard Borreson speakers at an audio show that were playing at ear splitting levels. I loved the sound and went back to the room a few times. On the afternoon of the last day when it was slow they played a hard core cut at concert volume which was fun to hear (I used to record hard core bands). My point is that there is no way that your speakers should be making any sort of snap at something like 90 dB. I would suggest contacting Borreson and ask if they have any experience with this. It will also be interesting to see if their customer service is commensurate with the price of their speakers.
Loud Snap at High Volume
I like to listen to orchestral music at fairly high volume. I have Borresen Z2 speakers driven by a D'Agostino Progression Integrated in a fairly small room: 13x16x12. At the peak of a crescendo, as you get in say the last movement of Mahler's 8th Symphony, the speakers will emit a loud snap, almost like the crack of a whip. I haven't measured, but I doubt I have the level much over 90db. I don't hear any distortion or break up before the snap. so it doesn't seem to be clipping. Which I can't imagine happening with the power of the DAG (200w into 8ohms/400w into 4 ohm) into a relatively benign 89db sensitive speaker that doesn't dip much below 4 ohms. I have read it could be loose speaker wire connections, and in fact the Shunyata Alpha V2 cable's banana connectors are not super tight at the back of the speakers. Or could it be the Z2's ribbon tweeter breaking up? Any insights would be welcome.