First Stack....

Discussion in 'Amps and Cabs [BG]' started by flaghard, Oct 30, 2004.

  1. flaghard


    Oct 17, 2004
    Ottawa, Canada
    I hate asking stupid questions, but i have been dealing with combos for my entire bass career and not being one with a nack for eomputer/electronic engineering, what kind of head can i plug into a 300 w, 4 ohm cabinet. if the head i want is 400 w, does that have negative affect on the cab??....a 2 ohm head hooked up to a 4 ohm cab is bad right?

    any help would me MUCH appreciated

  2. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    The Republic of Texas
    I'll start with the most important point first.

    A specific amp is designed to work into a certain range of impedence (some tube amps have specific outputs for specific impedences: 8ohm, 4ohm, whatever).
    The most important thing to know is the minimum impedence for which the amp is designed to work.
    Attempting to drive a cab or cabs whose combined impedence is less than the recommended minimum impedence of the amp can cause damage to the amplifier (& possibly to the cab(s) as well).
    Driving higher impedence with a solid state amp is no problem (usually results in less output power).
    I'm not sure how tube amps handle higher impedences; someone who knows, please chime in.

    As far as how powerful an amp to use with given speakers, it is good to have at least as much as the cab(s) is rated at (though depending on the cab's efficiency -- how efficiently it converts power into sound output -- it is sometimes possible to get decent output with less amp power, esp. if it is a tube amp -- just be careful not to drive the amp into harmful distortion, esp. solid state amps).
    A good rule for solid state amps, if you can afford, it is to have two to three times as much amplifier power as the cab(s) is rated for -- just make sure you listen to the cab(s) for signs of distress. This headroom means the amp is not being overworked and handles the brief peaks in music in a freely dynamic way, imparting a effortless, lively character to the sound.