Clipping question

Discussion in 'Amps and Cabs [BG]' started by Pthump, Aug 12, 2005.

  1. Pthump


    Nov 18, 2004
    If im running a 400 watt head into a 500 watt RMS cab, clipping can not hurt it, correct?
  2. Mcrelly


    Jun 16, 2003
    Minnesota, USA
    clipping doesn't automatically occur when your amp is rated lower than you cab. clipping occurs when you ask the amp to play louder than its designed (turning your volume knob past the point at which the amp can reproduce a sound cleanly)

    if you play past the point where the sound "changes" from a note to noise or distortion, if it sound like its "farting" or "scratchy" sounding then you should turn it down.
  3. el_Kabong


    Jul 11, 2005
    Nope, not correct. An amp that's clipping can put out more than it's rated output. I'm not an expert (I'm sure they'll be along shortly) but I think when an amp clips severely its putting out a square wave which will heat the voice coils. Also spells a very early death for tweeters.
  4. Yeah, that's about right. You'll hear distortion when clipping's happening, and the 400W RMS amp puts out quite a bit more when clipping. So you are correct, you are not safe from clipping your amp. My guess is it would be harder to blow the woofer, you're not getting that much over 500W out of the amp clipping to melt the voice coil quickly. The horn isn't designed to take that much extra high end from the distortion's harmonics though, it would be the first to go. If you have a limiter or compressor on the amp it should help keep you out of trouble somewhat.

    But you shouldn't have to worry about it unless you can't hear the amp clipping. If everyone's so loud you can't tell your amp is clipping, you won't hear the warning signs to avoid it. So I wouldn't worry about it too much otherwise.

  5. Can I ask a question? I went from a 9v Ibanez to a Stambaugh with an 18v and a 9v preamp in it. The 9 is for a piezo. Now when I turn up the mid boost or the bass to 8 or so (only one knob is needed) I get distortion. Is this the same thing? I have a Hartke 5000 biamped into a 4X10 and a 1X15. It's all running through a furman SPB-8 first. I assume that this is a different issue?

    Sorry for the derail!
  6. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    It is a different question. You're overloading the input stage of the amp. The supply voltage of the pre doesn't matter per se, but one with an 18 v supply in theory could pump out more than one with a 9 v supply. You'll have to play around with the gain structures all around to find what works best.
  7. That's what I was thinking. Thanks for the input! I've got to figure out how to bump it down. I'm going in through the active input. I've got some playing around to do!

    .... and now back to your regularly scheduled thread.