N802 possible tweeter buzz

What is the best way to check out a pair of N802's I have just recieved. My wife and I are hearing a buzz in the tweeters at a certain frequency. Just purchased from an audiogoner.What is the cost to repair? does anyone know, and is this something a handy person could do? Thanks for input.
If you hear a buzz from a dome tweeter, it is most likely produced by a voice-coil misalignment which causes it to scrape against the motor assembly (instead of remaining evenly within the magnetic gap) when driven, although it's not impossible that something like a bad solder joint at the driver or in the crossover could also produce similar symptoms. The first thing to do is make sure that the sound actually does emminate from the speaker and not from the signal being fed to it, so if you haven't already, swap your speaker cables at the amp end so that the other channel signal is now being fed to the affected side - if the problem resides in the speaker, the symptom shouldn't switch sides along with the channels. Conventional dome tweeter asssemblies (either the whole driver, or sometimes just the voice-coil/dome part, although in your case you can't really be sure the problem might not reside in the motor alignment itself, which could be negatively affected during shipping, although that's less likely than a problem with the former) are often not that hard to replace yourself, and usually not terribly expensive. But the B&W's tweeter is not all that conventional, so I'll defer to anyone with direct personal experience. And you can always contact the manufacturer or distributor. In any case though, you should enlist the aid of the member you bought it from, and see whether shipping insurance reimbursement can be claimed (but that's tough if the outer carton was undamaged).
I know with the N802, there is a cap thing that holds the tweeter in place during shipment. It is behind the midrange and tweeter. This might be the cause of the noise. If you already know what I am talking about and took care of it, no problem. If you arent sure, please feel free to email me and I can try to help you out.
If you really think that it is the tweeter hook your amp up to only the tweeter terminals and play music, very quietly though, you certainly don't want to overdrive it. If you do not hear the buzz then the high frequency buzzing is something else on the cabinet or room sympathetically resonating in response to the greater excitation caused by the midrange or, more likely, the woofer. Often, these resonances can sound like a tweeter problem. If the tweeter is bad just call B&W in the US. They were really helpful to me in the past.