blown speakers - i think...

[Chickenwings]

Hey all - just bought an old music man 2x10. NO sound. Plugged one of the speaker outs into one of my pa bins and i get sound. So - it must be the music man speakers right? If i plug the music man speaker lead in, then i get no sound at all whether I have the pa bin plugged in or not. Okay - it could be the wiring, but how do I check if it is only one or two dead speakers, or just old, broken wiring? Should I get a resistance reading across the +/- terminals on the speakers? Any other checks I can do before buying new speakers? I have a multimeter and no clue, but a good sense of adventure.

 

[The Golden Boy]

Re: blown speakers - i think...

Yes, you should get resistance across the terminals.

 

[mediumpimpin]

Re: blown speakers - i think...

Also, just inspect the speakers for any tears. Does the spider or voice coil look burned or torn? If the cones won't move, you can test them by VERY carefully pressing on them, then the speakers are done. If it's both speakers not producing any sound whatsoever, I'd bet the wiring is bad. Even if the speakers are blown, I'd expect some sound to come out of them, just a bad one.

 

[The Golden Boy]

Re: blown speakers - i think...

Even a torn speaker will make noise.

Look for a crease in the cone, it'll look like you had folded the paper and straightened it out. If that's the case, the speaker is blown like a mofo.

As far as testing for a blown voice coil, push down on the cone evenly, if you get a rasping sound, that's bad.

 

[WhammyBar Allstar]

Re: blown speakers - i think...

Disconnect the leads from the speakers to the amp and from eachother. You can use your meter first to check for an open connection on each voice coil. If it reads open, then it's gone. Use a "working" 9v battery across the terminals to confirm for an open voice coil.

If you get a resistance, this doesn't always mean that it's good, the voice coil could have warped from over heating and is melted to, or shorted to the gap inside of the driver/magnet structure. In this case, you can test the voice coil's pos or neg terminal for resistance to the magnet or frame of the speaker.