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Will distortion from pedal hurt my speakers?

Discussion in 'Amps and Cabs [BG]' started by shmedly, Jun 14, 2002.


  1. I have a new Fulltone Bassdrive pedal and I'm wondering if it will hurt my speakers when I use it. My setup is: Aguilar DB 750, Aguilar 4-10, Epifani 2-12, Fender P-bass Deluxe.

    I love my setup but up until now, I've played only clean and punchy. I recently started playing in a harder edged band and want to introduce a grittier, more distorted tone but am worried that it will hurt my speakers. Obviously, my cabinets aren't cheap and I don't want to find myself reconing speakers.

    What does everyone think? Am I worried for no reason?
     
  2. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    Yes and no.

    It depends on how you set the pedal. The different sounds that come froma distorted signal put more stress on speakers taht a clean sound.

    Also be careful about how much the signal is boosted when the distortion is switched on.

    If you are careful and setup the pedal wisely, you will have no problems. I use 2 distortion pedals (plus chorus, flanger, and EQ), and my speakers are fine.

    Peace
    Nick
     
  3. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    The distortion itself won't hurt your speakers. Too much power into them will.
     
  4. jerry

    jerry Doesn't know BDO Gold Supporting Member

    Dec 13, 1999
    Hawaii
    You might want to turn your tweeters down a little,
    distortion can be a little harsh with tweeters.
     
  5. jokerjkny

    jokerjkny

    Jan 19, 2002
    NY / NJ / PA
    in other words, nope!

    if i'm not mistaken, and Bob can correct me, a distortion effect pumped thru your speakers is nowhere near as bad like "power amp clipping" distortion, so it shouldnt affect your speakers at all. just be sensible about the levels your pumping with it on, run thru the effects loop for good buffering, and you're golden.
     
  6. It depends on how much you're using. You can fry tweeters pretty badly if you're sending a square wave through them.

    I use the Drive control on my EBS Fafner fairly liberally, and some nastiness comes out the tweeter, but that helps knife through a dense mix. I can't wait to get into a loud rock situation with it.
     
  7. Sort of.

    If a power amp that's clipping isn't putting more power into your speaker than the speaker can dissipate, it will NOT damage the speaker. Blown speakers are caused by two main things: Damage to the spider/cone/surround due to low frequency over excursion (this is the most common damage done to cone type speakers), or damage due to overpowering. Clean or distorted. People keep saying that square waves damage speakers, but even a pure square wave that doesn't have average energy greater than what a speaker is rated to dissipate won't blow up a speaker. ANY power amp would self destruct long before it's output waveforms were even anywhere close to pure square waves. Only the very tops of the waves get chopped even under the most severe clipping. Another myth that really irritates me is the myth that clipping power amps put out DC voltage. This is utterly false. The purest square wave is still an AC signal because it alternates (by definition). If an amp is putting out any kind of DC, it is very sick and has probably shorted an output transistor or something. Most power amps have adequate protection circuits which prevent DC from getting to the outputs in the event of a failure in the amp.

    Long and short of it: Don't worry about the distortion effect, it won't damage your speakers, but it might sound crappy through tweeters;)
     
  8. jokerjkny

    jokerjkny

    Jan 19, 2002
    NY / NJ / PA
    Those bastiges and their DC voltages!! :D;)

    thx for the explanation goat-man. but can ya clear somethin' up for me.

    if i've got a power amp that's pushing all of its 250 watts @ 8 ohms, running into a 1x12 cab that's 300 watts @ 8 ohms, the clipping wont damage the speaker?

    also, lots of guys use EH Big Muffs which push out gobs of fuzz madness. are these then considered dangerous due to their fuzzy square wave nature??
     
  9. Joker,
    if you're driving the 250 watt amp well into clipping into a 300W max cab, it may certainly damage the speaker. This is because the amp will produce more than its rated power when driven into clipping. Clipping is a gradual thing and the point at which it can be called clipping vs clean isn't really well defined. Some manufacturers will have the clip lights come on at 1% Total Harmonic Distortion (THD) and others might come on a 3%. The output waveforms don't immediately go to severely squared off waves, either. It's entirely possible that a 250 W amp driven hard into clipping might produce 300 or more Watts, depending on its power supply. Also, clipped waveforms have more average energy than sine waves of the same amplitude. So it's possible for a 250W amp to blow a 300W speaker by virtue of the fact that the amp can produce more than 250W when it's being driven into clipping. Note, this isn't due to the clipped waveforms as such. It's all about how much power the speaker can dissipate before it overheats and the voice coil melts.....:D But lets take a more extreme example: Say you had a 50W amp into that same 300W cabinet. No matter how hard you clip that amp it isn't going to be able to produce more than 300W and you could clip it all day (supposing it didn't thermal out, which is what it would do in the real world) into that speaker and not worry about blowing it. But you could also easily blow that 300W cabinet with clean power from a 1000W amp. The physics of speaker failure and amp clipping are pretty complex but that's the jist of it. I hope this all makes sense, I have a tendency to go on and on about stuff :D...
    Nah, there's nothing to worry about using Big Muffs and such.
    Also, 90% of the cone speaker failures I've seen have been mechanical in nature. Voice coils off center in the gap, from overexcursion or handling abuse; surrounds ripped from the cone, from overexcursion; voice coil lead wires ripped out, from overexcursion..... You see what I'm getting at? Overexcursion is is by far the most common cause of speaker damage. So, just make sure that your cabs can produce the amount of low end that you need without excessive cone movement and you'll be OK.

    EDIT: typos
     
  10. jokerjkny

    jokerjkny

    Jan 19, 2002
    NY / NJ / PA
    goat-ee,

    you da man... :cool:
     
  11. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    Spacegoat, thanks for the explanation.

    If distortion in and of itself were the problem, there would not be an unblown Celestion guitar speaker in the world. Guitarists routinely send distorted signals--reflecting pedal distortion, preamp distortion, and power amp distortion--into their speakers. If distortion were so terrible for speakers, they would blow their speakers every single time, or near enough. But they don't. You're right--you can send a heavily distorted 5 W signal into a 200 W cab all day, and nothing will happen.
     
  12. What about horn tweeters, though?
     
  13. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    Check this out:
    http://www.rane.com/pdf/note128.pdf

    As I read it, the issue is not that the mere presence of a clipped wave is inherently harmful. It isn't. The problem comes when the clipping occurs in a setting whereby the amplitude compression associated with clipping results in an abnormally high level of power being delivered to a component that can't handle it. In other words, it's not a "funny wave shape" problem, exactly, it's still a "too much power" problem. If you're brutally overdriving a 200 W amp into a system with a tweeter rated at 25 W, a situation could arise in which more than 25 W hits the tweeter and the tweeter could be damaged. But if you're overdriving the daylights out of a .5 W amp into a system with a tweeter rated at 100 W, you're basically not going to hurt anything.
     
  14. Fuzzbass

    Fuzzbass P5 with overdrive Supporting Member

    My understanding has been that un-musical square-wave distortion produced by transistor amps (as opposed to the musical rounded-off distortion produced by tubes and tube emulators) *can* harm speakers even when the power level is less than the rated level of the speakers. This is because with a square wave, there is no transition... the speaker attempts to travel from full forward (and hold) immediately to full backward (and hold), which is not a natural motion.

    I once blew a friend's bass speaker by running a minimoog through it at a relatively low volume, so it makes sense to me... :oops:

    ...but if my understanding is incorrect, would someone please explain? Thanks!
     
  15. This is not actually the case. It would hold some water if amps produced true square waves when clipping. The truth is that they don't. Even under the most severe clipping only the very tops of the output waveforms are squared off. So during a cycle the speaker moves normally for most of the waveform even under severe clipping. It is true that clipped waveforms have more average energy than sinusoidal ones, but if this energy is less than what the speaker can dissipate, you won't blow the speaker. Also, solid state distortion doesn't have any more or less square wave content than tube amp distortion, and is not any more harmful than tube amp distortion. The so-called softer clipping of tube amps is a myth. Tube amp distortion sounds better because it has different harmonic content. Overdriven transistors tend to produce more odd order harmonics, which sound harsh to our ears, while overdriven tubes produce more even order harmonics, which are more musical. I've had both tube amps and SS amps on a scope, being driven well into clipping with a test tone. The resultant waveforms look exactly the same when the harmonics are filtered out. There are people who will disagree with me on this, but I've yet to hear a scientifically sound argument as to why.
     
  16. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Spacegoat / Mark, you da man! Excellent explanations … you've sure done your homework! Thanks.
     
  17. Fuzzbass

    Fuzzbass P5 with overdrive Supporting Member

    Awesome! Thanks very much, Spacegoat.

    Just goes to show: you can learn something new every day.... and you can unlearn something old, too.
     
  18. Thanks guys. Applying the stuff I'm learning in school to the stuff I've seen in ten years of pro audio experience has been enlightening at the least. I'm glad to be of service and I hope my posts make some sense to the less technical people around here. Please tell me if they don't! Thanks for your kind words, Bob.
     
  19. Damn, I just finished my final physics exam and now I feel like i am back in the class again. :p

    Anyway, wow that's a lot of information to know. You know your stuff spacegoat. I think my brain would explode if i knew all that stuff.

    (This reply had no meaning what so ever so disregard this and please move on with your talkbass exploring.)