How do I know if speakers are blown?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by ChazMania, Dec 15, 2005.

  1. ChazMania

    ChazMania Silver Supporting Member

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    I sold an older 2x12 cab last night that has 85w Celestians. I have used this cab off and on for about 12 years. So, guy comes over and plays through it, sounds as it always has to me, he buys it. He emailed me this morning saying:

    "both speakers are slightly blown on the cab.so its basically worth nothing to me unfortunately. theyre still playable obviously but they make this really crappy distortion for the first second after you play a power chord on clean or overdriven, then after the first second or two, it disapears. it sounds exactly like my other blown speakers i use at work"

    So, I feel bad and will buy the cab back from him for sure, I'd never want to give anyone a bunk deal. How do I know for sure if the speakers are blown? I guess there is no way to tell "they were fine here, then he blew them last night"...right?

    I searched a few other "blown speaker" threads and didn't clearly come up with a way to know if they are toast or not. I appreciate any help guys....
     
  2. axolotls

    axolotls Guest

    take the grill off, push on the speaker, and if it makes a "shhh shhh" noise then you have a voice coil going out, this also causes the distortion that he described.

    i just blew a voice coil, damned octave pedals. looks like im going to have to get a couple of webers.
     
  3. bob-i

    bob-i Member

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    That's actually a bad idea. If you push unevenly you can damage a good speaker.

    "Slightly Blown" usually means that the voice coil has dropped some of the windings. This can happen over time with no abuse, just age and the glue drys up. If the guy listened and was happy, then it's his loss, not yours.
     
  4. bob-i

    bob-i Member

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    Oh... I forgot...

    The best way to determine if a speaker is damaged is to connect a sine wave generator. Sweep the sine wave through the frequency range of the speaker and listen for any buzzes or rattles.
     
  5. 1guitarslinger

    1guitarslinger Member

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    Be careful YOU don't get a bunk deal. If the guy tried the cab before he bought it, it's his. You don't know what he did to the speakers after he got it home.

    Just my 2 cents...
     

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