# Can synth or fuzz pedals blow a speaker?



## hardasmum (Apr 23, 2008)

I was playing my EQD Bit Commander last night at rehearsal. I was really getting into the square wave distorted synth goodness when it occurred to me, can this damage the speaker? 

The effect makes it "sound" like it's ripping the speaker to shreds, but at high volume can it actually blow it?


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## LowWatt (Jun 27, 2007)

The question is more about your speakers than the pedal. I have a bit commander and love it and use it with guitar and bass rigs all the time. I'm especially all about the 1 and 2 octave down sound. It used to scare the shit out of me with an AC30 with 2x15w Webers in it because I know bass notes are harder on guitar speakers than midrange, but on anything where the speakers were rated for about double the rating of the amp, it's no worry whatsoever. I've hit them all hard and not seen the slightest thing to worry about.


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## loudtubeamps (Feb 2, 2012)

Yeah...._prolonged_ *square waves* at "DEFCON 1"are :2guns:death to most speakers.


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## mhammer (Nov 30, 2007)

There are two things to be concerned about: excessive transients that produce more instantaneous power going into the speaker than the voice coil was built to withstand, and sustained high-frequency energy going into the voice coil that exceeds the rate at which the speaker can dissipate heat buildup.

We've all heard about, or seen, the boy scout trick of rubbing sticks together to produce sparks that start a fire with the right tinder. It can do so because if you rub fast enough, the heat generated by the friction builds up faster than the sticks can get rid of the heat. So it accumulates until...poof!

Voice coils also build up heat when they move fast over sustained period. Most quality speakers are designed to dissipate heat efficiently so as to increase their power handling. Some will even have fins on them to dump the heat, and some will use ferrofluid to help the coil stay cooler. Feeding the speaker a sustained wide-bandwidth signal that is low in amplitude will not generate as much heat build-up as the same signal run at higher volumes. So, if one is feeding a speaker a steady-state wide bandwidth signal that requires the speaker to move a LOT and very fast, the potential for heat build-up is increased. If the speaker is well-designed and able to dump the heat, fine. But unless you know the speaker is able to handle that sort of bandwidth and steady volume for a prolonged period, best to ease back a bit, just to be safe.


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## loudtubeamps (Feb 2, 2012)

Agreed: Also: A typical speaker and voice coil were not designed to reproduce squarewaves efficiently.
A low wattage rated speaker will handle a wack of wattage far exceeding its rating if the signal applied is a smooth complex sine wave.
I've seen low wattage square and sawtooth complex signals destroy speakers that had a higher R.M.S rating than they were being fed.
Why Too Little Power will NOT blow Your Speakers


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## hardasmum (Apr 23, 2008)

Thanks for your replies. I'll have to dig a bit deeper online, but so far I haven't found anyone complaining about a POG, Bit Commander etc blowing a speaker, but maybe I need to change my search terms.


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## loudtubeamps (Feb 2, 2012)

guess it boils down to speaker wattage capacity V.S. amp output x position of volume knob over:
 time spent (cubed) grooving on one note divided by what yer' smokin'


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## hardasmum (Apr 23, 2008)

loudtubeamps said:


> guess it boils down to speaker wattage capacity V.S. amp output x position of volume knob over:
> time spent (cubed) grooving on one note divided by what yer' smokin'


 I am probably okay. 30 watt amp, 50 watt speaker.


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## hardasmum (Apr 23, 2008)

Double post


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## loudtubeamps (Feb 2, 2012)

hardasmum said:


> I am probably okay. 30 watt amp, 50 watt speaker.


Yup, you're probably right, should be fine.
If you smell something like insulation or varnish, time to back off.
Cheers, d


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## mhammer (Nov 30, 2007)

Just keep in mind that the manner in which speakers are rated can vary, and not necessarily represent what you believe they do. Certainly nobody rates their speakers in terms of how much power it can tolerate at high frequencies for prolonged periods. Taking a momentary 200hz thump at 40% over the RMS power rating is one thing. Reproducing a 30% duty cycle 10khz signal at that power for 30 minutes quite another.

Again, think in terms of the rubbing sticks analogy, and the risk of fatal heat build-up, given speed and duration of rubbing.


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