Overpowering cabs

Discussion in 'Amps and Cabs [BG]' started by Insomniac, Jul 30, 2002.

  1. Hey all,

    i was wondering if it is possible to overpower cabs and harm them by using heads that are maybe 50 watts louder than the cab. I heard Ampeg wires resistive bulbs to prevent this. But say i had an SVT 3 pro(450 watts) going through a 4X10 with a 400 watt max. If the amp was not played at full power, would the cab break?...Any suggestions would be great
  2. Just don't crank up the gain and volume on your head and you'll be fine. Cabs don't care how much power goes through them. :D
  3. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany

    First of all, your amp will never put out the full 450W over an extended period of time.
    Also, the cab's power rating is derived from feeding a certain signal into it. The signal is never the same in real life, so it can usually handle more power.

    I remember reading on some company website that they think it's totally ok to hook up an amp with twice the power rating (of the cab) to their cabs.
  4. Not likely. In fact, it is recommended by speaker (JBL) and amp manufacturers (Yorkville) that you over power your cabs by a factor of 2 to 1 to help prevent clipping the amp and hosing the drivers.
  5. Matthias


    May 30, 2000
    Vienna, Austria
    I agree with JMX and Mudbass.
    One manufacturer (I don't remember which) puts it the best way IMHO: the amp should be rated 50%-200% of the cab's RMS power rating.
    As long as you respect the limits of the amp (=avoid clipping) and the cab (avoid excessive cone movement) you will be fine.
    And even if the amp and the cab have exactly the same power rating, this does NOT mean that you couldn't damage either the head or the cab!

    My bottom line:
    If you want to get the most out of a given head get a loud cab - the power rating of the cab can be much higher in this case (e.g. 350W head through an 8x10)
    If you want to get the most out of a given cab get a head with about twice the rated power - this way you will have lots of headroom and you can drive the cab to it's full potential. (e.g. 800W head into a 2x10 with 400W).

  6. ohmanohjeeze


    May 6, 2001
    tucson, az
    no! your amp will break into pieces and explode!!
  7. jokerjkny


    Jan 19, 2002
    NY / NJ / PA
    uh.. uh... ohmanohjeeze!!!!
  8. Golem II

    Golem II

    Jan 4, 2002
    Macon, GA, USA
    I still have shrapnel wounds and 2nd degree burns from the time I powered a 300w cab with a 301w amp.
    But I was downright lucky then, compared to the time I drove a 200w speaker with a 100w amp... the speaker shot right out of the cab, killing my drummer. You'll be missed, Alex.

    If you plan on drastically overpowering a cab, you may want to check the cab's sensitivity specs. While Acme (known around here as the kings of inefficiency) pretty much acknowledge that you need double the rated power to get some decent volume out of them, you may not want to pump that much power into a more efficient speaker.