Slight buzz on Quad ESL-63..

Well, UPS brought me one of the 2 speakers...tomorrow I hope the 2nd one..

But, I have noticed on a Brian Bromberg CD called WOOD, that the speaker buzzes a bit at the lower registers of the acoustic bass notes...

I am wondering if some of it is normal, or is it a problem ? If feels to happen on the top side..

Thanks in advance!
Hi. Nice speakers. If this issue continues, it could indicate a panel problem. If you are in USA and need repairs, there are 2 companies that provide exceptional service. On the east coast, check out QS&D @ 540/372-3711. The other company is in California. If you need that info, let me know; I need to look up the contact info.
My quads sort of rattled when you over drove them with highly percussive bass notes, and on high frequencies I got a low level buzz from piano notes in a narrow frequency band. Don't know if its the same cause of both problems, but a Quad garu told me to retension the dust cover. This can be a DIY project if you are ambitious and VERY careful. I'm sure someone can give you specific instructions. I'm not sure this is the cure, as I recall reading a review of the Quads a long time ago in which the reviewer referred to a tizziness - I didn't relate to what he was saying at the time.