Dead Woofer in Opera Active PA Speaker

The other day I got my two Opera Live 210 active PA speakers out and I noticed that in one of them only the tweeter was working. Oh no! So I decided to take it apart since it is way too old to be eligible for warranty. I was really surprised how well designed they are! Everything is neat and clean and almost as if they are made to be taken apart. What I found though was’nt that cool: I measured resistance of the speaker coil in the woofer with my multimeter and got an incredibly low .6Ω. Well I guess that means that it is practically shortened, probably in an overload situation. That’s very strange since these speakers are active and have a built-in overload-protection-circuit. I guess it didn’t work so well. ;-( To see if the part of the active amplifier that drives this speaker still works I hooked up my multimeter to its outputs without the woofer being connected. Turning the volume up or down didn’t change the displayed 0V. My guess is that this means that the short in the woofer also killed the amp in the process. That’s really too bad, because I really liked these speakers. They are no longer manufactured.

One funny thing I also found is that some screws had come loose over the years. They are used to mount the OpAmps to a cooling brick. One of those three screws had vanished so I looked around inside the case and I found it: it was clinging to the speaker’s magnet!

Listen to the awful sound of only a tweeter. I recorded the speaker before taking it apart: