Is it highly possible the shop made some type of mistake and if so what kind of mistake would have blown speak

Question

I had 2-12"jlw6v2 hooked to a 760 watt amp the problem i was having is as long as i kept my volume under 22 the would play fine if i turned it up any louder than 22 the bass would go out and pop back in when i turned it back down to 22 or less.So i took it to a shop still working and playing.After the shop took the woofers out of the box and did whatever and put them back in they weren't working at all and the told me the voice coil was bad, When different shops told me it didn't sound like a speaker problem but like a power problem and that if they were working when i got their and before the took them out of the should have been working when they put them back in.Also the speakers were blown and if that's the case they had to have blown them because they were working when i got their and before they took them out of the box. So can anyone tell me what could have possibly happen while my speakers were out of the box or any type of useful info that might help in my small claims suit.

Answer 1

well if the sub is blown there isn't anything you can really do except replace them but those speakers are really expensive so probably why your trying to fix it. but i probably the reason your speakers blown was from the improper way your speakers were wired. jl's are specific to how its supposed to be wired and they also have a special type of wiring were you have to series or parallel the speakers through a different  terminal and when they took it out and adjusted it they probably didn't connect then properly and it was only running a single voice coil crippling the second one causing your speaker coil to be destroyed.

Answer 2

It does sound like the original problem was with the amplifier, not the speakers, so I don't know why the installers removed them from the box.  It's possible that you had them wired at too low an impedance, and they re-wired the voice coils in series to reduce the strain on the amp.  If, for example, you had one damaged voice coil on the sub, it might work when wired in parallel (through the one remaining voice coil) but it wouldn't work when wired in series.  This seems like an unlikely scenario, but it's possible.  

I can't imagine what damage could have been done to the speakers when they were removed from the box.  They couldn't have blown a voice coil just from removing and remounting the subs, but they might have damaged the speaker terminal or tinsel leads.  Have you removed the subs from the box and checked for physical damage (or checked that they're connected properly?)