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Is it safe playing a small guitar amp distorted through a bass cabinet?

Discussion in 'Amps and Cabs [BG]' started by a e i o u, Jun 8, 2004.

  1. I was hoping this would be safe but I want to check here first. I have a 30 watt guitar amp that I want to play guitar through. It has a speaker out. If i hook up the amp to my avatar 4x10 bass cab, will I be good to go playing my guitar through it distorted? I want to use it to be loud enough to play lead in my friend's band.
  2. This is perfectly safe for the 10s but not for the horn. I would turn down the horn all the way and rock out!
  3. tmu


    Mar 14, 2004
    I disagree. I if you have a solidstate power section on the amp, playing it distorted through the cab cranked (thus disorting the powersection) can cause DC current to run through the speaker, and burn out the voice coils! Be careful!
  4. Saetia


    Mar 27, 2003
    I thought distortion on solid state amps is just a circut making artificial distortion? Not distortion from the amp actually clipping. I can see how it would be bad for the cab if the power section on the solid state amp was cliping, but on a solid state guitar amp I don't believe the lead channel distortion to be from clipping but from a circut (kind of like a stomp box). Tube clipping gives you a great overdriven sound which isn't bad for your cabs, you clip a solid state and it can do damage.

    I've played guitar through my cabs with both a crate solid state head with distortion and a peavey 5150 II head (6 power amp tubes, 4 pre amp tubes) with overdrive without running into any problems. Bass amps make great guitar cabs, very smooth, tight, and have great low end.

    Do as suggested and turn the tweeter completely off, it will sound like crap and will blow your tweeter.

    I'm tired, please forgive any spelling errors or general discombobulation in my post.

  5. tmu


    Mar 14, 2004
    the problem with a 30 watt amp is that it may be clipping in the power section even if you do not realize it.
  6. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    If you turn the horn down you'll probably burn out the attenuator. Safest to disconnect it completely.

    Rubbish. No correctly functioning 30W amp, regardless of how heavily it is overdriven will either put out DC or sufficient power to damage a 1400W rated cab. I really wish this myth about DC and 'underpowering' would die!

  7. All distortion is something being clipped. Pedals/distortion circuits either used diode clippers or they overdrive transistor circuits. It's exactly the same mechanism as power amp clipping except using lower signal level devices.
  8. Oh yea I didn't think of that. I agree completely
  9. geshel


    Oct 2, 2001
    Well - the attenuator should be rated at at least 50w. It's wires are probably a pretty good deal thicker than the voice coil wires in the horn. I'm not sure how hot one of these gets if you put 50w into it continuously, but the amount of power above 2kHz in even a distorted 30w guitar signal is probably not more than a couple watts.

  10. tmu


    Mar 14, 2004
    Exerpt from Eden Speakers Manual:

    Too small an amplifier, when pushed to its limit, can generate clipping – a signal with enough high frequency distortion to burn up a voice coil.

    Exerpt from SWR Speakers Manual:

    Continuous clipping is very harmful to speakers, especially in a bass system: the lower the note, the
    longer the duration of DC content in the clipped signal. To understand what happens under this condition,
    remember the example of what speakers do when a 9 volt battery is applied to them. Now
    imagine what 20 or even 50 volts would do at the rate of 40 times per second! The results can be
    overheating, disfiguring of the voice coil, overall fatigue, and—eventually—complete failure.

  11. geshel


    Oct 2, 2001
    A bit misleading. It's not the "DC component" (which there is none of) that can cause problems. It's the sharp edges and spikes (transients). A large woofer cone can't respond to these signals very well. What happens is that most of the power, instead of being translated into sound and dissipated in the air, gets converted into heat by the voice coil or the cone (through internal friction as the cone flexes, instead of moving as a whole). This is what can cause problems.

    Anyway, a 4x10 should be able to handle a 30w guitar head - if old Fender bassman cabs could, a new Avatar should do just fine.