thank you, Aadams. I had them connected to my NAD receiver - so when one channel died, after buzzing sounds, I assumed speaker.
Eventually, swapping everything, I found that my NAD somehow, for some reason, lost the right channel.
I swapped in a Jolida, and viola - it's working. More or less - the buzz is still there. Sounds like the voice coil on the woofer is dragging.
No, I found these at a church sale; they had not been opened up before - I had a heck of a time getting the woofer unsealed to look inside.
But anyway, I need a replacement woofer now. What's the best source, this side of ebay? Or - I can start a new thread. Either way, thanks