I happened to stumble upon a pair of 7C's today and got it for $60.
It sounded okay but had one tweeter dome pushed in.
When I set them up at home, I noticed that tweeter is not sounding right.
Treble is there but it's not smooth and little off compared to the other good one.
I looked closer and saw whatever pushed the dome, it caused a small portion of that copper vc to come up slightly out.
I tried to push it in the gap but it's no use.
I guess time to replace?
I don't want to spend $100 for RDO on these so hunting time in the epay for single SL-2000.