I'm pretty sure they've replaced the mid/bass driver in both speakers! Obviously one driver looks pretty much the same as another, but (call me sad), these both look different! The grain on the keraform (?) looks different!

When I bought these s/h they'd been getting little use for a while. The guy had his replacements up and running. He warmed them up before I got there, but they still seemed to wake up MOre after a few days of continuous use back at mine. Sounds pretty good ok, even less bass than before  but I guess it'll all kick in again soon....