Can a huge jump in amp volume blow your speakers?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by 3Sides, Feb 26, 2005.

  1. 3Sides

    3Sides Member

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    Might be a dumb question, but yesterday I had a 4 channel 100 watt amp hooked up to my THD 2x12 cab. I normally keep the volume level at about 3 on all the channels. I guess when I was moving the amp I hit the volume knob on the dirty channel.
    Anyway, I am playing in the clean channel and then I switch to the dirty channel and BAM. The loudest, crushing sound I ever heard come out of the amp. I backed off the volume on the guitar immediately and looked at the amp. It turns out the volume on the dirty channel was at 8! When I switched channels the sound was so loud and abrupt it knocked an empty can off a table 15 feet away!

    The cab still sounds OK, but I was just wondering if something like this could hurt it? The speakers are rated at 80 watts so they can handle the power, but what about the abruptness of the volume change?
     
  2. John Phillips

    John Phillips Member

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    Don't worry about it. If the speakers can handle the power, they can handle the power, period. They are subjected to the same violent cone movement within a very loud sound anyway.

    The only thing that might be an extra hazard is excessive bass.


    I'd have loved to see the look on your face when that happened ;). I saw someone do the same thing with a 160W Fender Stage 2x12" combo once... it was like that bit in Back To The Future...
     
  3. 3Sides

    3Sides Member

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    It was like Back to the Future! I simultaneously hit an open E power chord and kicked in the overdrive channel and it sounded like a bomb went off. Having the pop can fall off the table from the sound just added to the shock of the whole situation
     
  4. Andy H.

    Andy H. Member

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    If the cab still sounds okay it probably is.

    You don't say if the amp is a valve or solid state model. If it's a valve amp then basically no problem. But with solid state amps if you distort the output section then you get pretty much a square wave signal, ('hard clipping'), which is very unkind to speakers and can quickly damage the voice coils of drivers, even those of a much higher power rating then the amp.

    Basically when fed a square wave signal the speaker cone will spend most of the time either fully in or fully out, and very little time travelling between. It will overheat and can be damaged quite quickly. Overdriven valve output sections overdrive or clip 'softly' though, tending not to produce these harmful square waves.

    Hopefully your speakers are fine. Ditto your ears!

    Andy.
     
  5. 3Sides

    3Sides Member

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    Yes it was a 100 watt valve amp. It appears to still sound good. I just posted the incident here in case there might have been a test or some type of evaluation to check if the speakers received any damage that might be inaudible.

    Lucky I was standing off to the side of the amp. I can't imagine how loud a direct hit would have been.
     
  6. Jon Silberman

    Jon Silberman 10Q Jerry & Dickey Gold Supporting Member

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    If you're not sure whether the speaker survived, I say, do it again as a test. ;)
     
  7. 3Sides

    3Sides Member

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    :D :D

    I was thinking of doing it again just to see how many cans I could knock over @ 15ft.:dude
     
  8. rockon1

    rockon1 Member

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    I think a hugh jump in volume COULd damage your speakers. However if they are still working such is not the case.
     

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