Does distortion effect increase risk of blown speakers?

[Ryan.]

Bass player considering a distortion peddle. Sometimes I run it through the mains and subs. Other than an obvious increase in gain from the peddle itself does the actual effect increase the odds of blowing something?

[Mogwix]

Nope.

[Ryan.]

Excellent.

[RoadRanger]

Not really.

[agedhorse]

Yes, it most certainly increases the average power delivered to the speaker PLUS if your cabinet has a tweeter it will increase greatly the proportion of signal (harmonics from the distortion effect) to the tweeter. Per the old JBL tech notes, I would derate the speaker's capacity by 1/2 to compensate for this effect.

[Ryan.]

Lol, and Aged comes in with the rebuttle!

 

So okay... let me get this straight...

 

1) I have clean bass running into the mixer. I PFL and set the average level at -3.

 

2) I have the distortion bass running into the mixer. I reset the gain so the average level is back to -3.

 

So with both levels averaging at -3 the distortion still has a higher chance of blown speaker?

[RoadRanger]

#2 will be a lot louder than #1. You'd want to turn it down to the same loudness which might have the VU meter lights 3 or even 6db less. A mic'd guitar amp running with distortion is worse.

[Ryan.]

 

#2 will be a lot louder than #1. You'd want to turn it down to the same loudness which might have the VU meter lights 3 or even 6db less.

 

 

So wait, if you have the PFL on two different sources playing at the same level, one can still be louder than the other?!

[RoadRanger]

So wait, if you have the PFL on two different sources playing at the same level, one can still be louder than the other?!

Yes, especially if the VU meters are peak reading as opposed to RMS reading. I believe most on low end consoles are peak reading these days? The old fashioned "needle" VU meters were usually RMS reading.

[Ryan.]

Okay I looked that up. Root Mean Squared. No clue what that means.

 

So I'm guessing we're now getting in to sound physics (side note: when I took a physics class in high school this was the one section they didn't teach to the students from the book) so I know nothing about it.

 

So even though my reading on my meters is equal for two different inputs at the same fader level, one can be louder. That is good to know.

 

Sound is weird stuff.

[Mogwix]

 

Okay I looked that up. Root Mean Squared. No clue what that means.

 

You understand the difference between AC and DC right?

 

An AC signal passing through a given resistor will create the same amount of heat as a DC signal that matches the RMS value of the AC signal. This basically describes the relative "power" of an AC wave.

 

Different waveforms of equal peak-to-peak voltage will have more or less power depending on their shape. Due to their nature, clipped (distorted) AC waves have more RMS power than sine waves.

 

The basis of my original answer is essentially based on a few things: one, the change shows up on the meters, and two, for your application it won't increase the chance of damaging speakers unless you're already running them on the edge of safe operation regardless. The distortion effect isn't necessarily the same as the clipped waveform that comes out of the output of a mixer that's distorting. Doesn't necessarily have the same characteristics.

[agedhorse]

For a given peak voltage, a heavily distorted signal will have 2x the average power but the same peak power.

[Mutha Goose]

 

For a given peak voltage, a heavily distorted signal will have 2x the average power but the same peak power.

 

 

depending on crest factor

[agedhorse]

 

depending on crest factor

 

 

For a sine wave (my assumption as a reference) the crest factor is defined by the example. Sine wave crest factor is 3dB, square wave is 0dB. With the same peak voltage, the square wave will have 2x the "RMS" power.

[Mutha Goose]

 

For a sine wave (my assumption as a reference) the crest factor is defined by the example. Sine wave crest factor is 3dB, square wave is 0dB. With the same peak voltage, the square wave will have 2x the "RMS" power.

 

 

Agreed. My point was simply that the distorted signal will be somewhere between the sine wave and the square wave. Therefore, the true RMS level will also be somewhere in between the 1x and 2x.

[Mutha Goose]

And I guess, now that I am thinking about this more relative to the OP...

 

Let's assume you have a 100W amp feeding an 8-ohm load. In this scenario, the gain of the amp will be ~60dB. And, as just discussed, the use of a distortion peddle, will increase your effective input level by something less than 3dB (which BTW, is less than the difference between some passive and active pickups).

 

So to bring this back to the original question, will this extra 3dB increase the chances of blowing a speaker? I would think that the system would be horribly designed if the driver had less than 5% of margin, so my guess is not in the practical world.

[Craig Vecchione]

For those who may be struggling to understand the differences in power, draw a sine-shaped wave, and superimpose a square-shaped 'wave' with the same peak. Note that the square wave have more volume inside the lines than the sine. That volume represents power. If you get that, next try the same thing, only this time draw a sine, and then draw a clipped sine with the same peak. You'll notice that the clipped sine has more volume than the clean sine.

[The Chinese]

i wonder how confused the op is now?

[Ryan.]

 

i wonder how confused the op is now?

 

 

Very.

 

But I got the answer. I'll work on the knowledge behind it.

[agedhorse]

 

And I guess, now that I am thinking about this more relative to the OP... Let's assume you have a 100W amp feeding an 8-ohm load. In this scenario, the gain of the amp will be ~60dB. And, as just discussed, the use of a distortion peddle, will increase your effective input level by something less than 3dB (which BTW, is less than the difference between some passive and active pickups). So to bring this back to the original question, will this extra 3dB increase the chances of blowing a speaker? I would think that the system would be horribly designed if the driver had less than 5% of margin, so my guess is not in the practical world.

 

 

Has nothingto do with the extra 3dB of gain, it has to do with (in this case) the thermal energy being delivered to a speaker and if you are operating it at rated power, adding more power without realizing it, can lead to speaker failure.

 

When sending a distorted signal to the speaker, the real power must be acknowledged, and an amp can deliver ~2x it's rated power to a speaker with heavily distorted signal so the speaker selection should reflect this potential if distorted tone is your goal.

[dboomer]

Distortion itself doesn't damage a speaker. A clean signal at level X and a distorted signal at level X will have the same mechanical impact (given the same freq bandwidth). What Andy is pointing out is that if you simply add distortion to a signal you will be delivering more power to the speaker. As long as you observe the speaker's power handling and mechanical limits you will be fine. Once you exceed them you've got trouble ... but it doesn't matter what the signal looks like, only that you exceed the limits.

[agedhorse]

 

Distortion itself doesn't damage a speaker. A clean signal at level X and a distorted signal at level X will have the same mechanical impact (given the same freq bandwidth). What Andy is pointing out is that if you simply add distortion to a signal you will be delivering more power to the speaker. As long as you observe the speaker's power handling and mechanical limits you will be fine. Once you exceed them you've got trouble ... but it doesn't matter what the signal looks like, only that you exceed the limits.

 

 

Exactly, and many folks don't realize that a power amp can deliver more than their rated power under such conditions, damaging speakers is then a surprise.