Power amp settings ("to bridge or not to bridge, that is the question")

Discussion in 'Amps and Cabs [BG]' started by JohnL, Oct 6, 2000.

  1. JohnL


    Sep 20, 2000
    Grayson, GA
    Twofold question:

    First, I have a preamp & Crest power amp driving a Hartke 4x10XL cabinet. The amp is 250w/side, 500w bridged mono. The cabinet is rated at 400w. It is a stereo amp, but since I only have one cabinet, am I better off using only one side of the amp, or using the bridged output? (I have been using the bridged output)

    Second, the amp has only an on/off switch on the front panel, with small pots on the back panel to adjust the output. Should I max the output on the amp and use my preamp gain to adjust volume, or should I back off the output of the amp and adjust the preamp gain higher? It has been working fine up to now, I just dont want to blow the speakers due to long term damage. Thanks!
  2. Rockinjc


    Dec 17, 1999
    Please read the whole message before you blow something up!

    I think you will be happier if you bridge your output and raise the volume on the power amp to about full. Hopefully you have peak lights on your amp and an automatic limiter that can be set to on. Your amp may also offer a low cut filter that could be set to remove frequencies that are below what your cabinet can produce. But in general it is more hazardious to the cabinet to drive a lower power amp to distortion that to use more watts than you need.

    If you had another cabinet and wanted to biamp your rig, it might make sense to use stereo mode, but that usually is done with more powerful amps and requires a crossover.

    These are generalizations as there are a few details that might help.

    Is the Cab 8 or 4 ohms? - This is important. Some amps will not handle 4 ohm bridged

    What amp do you have? - Is this a CA 2? It won't do 4 ohms in bridge mode!

    The Crest site shows that the CA series amps as adequate for your application. Just make sure NOT to bridge if your amp say's it cant handle the ohms on the cab in that mode.

    If their amps are as good as their toothpaste, you are all set.

  3. I second what Rockinjc said.

  4. JohnL


    Sep 20, 2000
    Grayson, GA
    I will check the ohm rating, but I wouldn't have thought Hartke would have an 8-ohm rating as a stand alone, since so many of these are stacked together. Thanks for the info!
  5. JohnL


    Sep 20, 2000
    Grayson, GA
    whoops! I meant to say I would have thought it would be an 8 ohm rating as a stand alone!