3 8 ohm cabs = How many ohms?

Discussion in 'Amps and Cabs [BG]' started by Ty McNeely, Mar 9, 2002.

  1. Ty McNeely

    Ty McNeely

    Mar 27, 2000
    What would the impedence of 3 8 ohm cabs be (1 cab out of one input, then another cab out of the other daisychained to a 3rd).
  2. I'm not quite sure what your question means.

    Nevertheless, you can work out the vaue of any number of resistances parallel connected by the formula:-

    1 / (1 / R1 + 1 / R2 + 1 / R3)

    The answer to 3 x 8 Ohm cabs in parallel = 2.66 Ohms.

  3. Ty McNeely

    Ty McNeely

    Mar 27, 2000
    See the attachment to see what I meant. I was tired when I wrote that:p

    So in other words I can run 3 cabs as long as I don't mind running my head at 2 ohms?
  4. The three 8 Ohm boxes in that configuration will give 2.67 Ohms if the two output jacks are from the same amplifier (ie a mono amplifier). If it's a stereo amp (like the Eden 800) the two outputs could be from different amp channels. This would create a different impedence situation. For mono amps, if there are two speaker outs they're just paralleled internally.
    Go for it if your amplifier is rated to drive 2 ohm loads. If it doesn't specifically say it can drive 2 ohms don't do it.....
  5. leftybassdog

    leftybassdog Senior Supporting Member

    spacegoat is right, look at the the back of your amp and it should be marked with the mimimun ohms the amp can handle,3 8ohm=2.66 or 2.5 most amps are set for a mimimun of 4 ohms but eden,swr,ampeg,and some others can drop down to 2 ohms, example swr 350, two ohms is the lowest,but the swr 750 will only drop to 2.5 or 2.66, be sure to check if you dont it can burn up your amp,
  6. Ty McNeely

    Ty McNeely

    Mar 27, 2000
    Its a Sunn and it does go down to 2 ohms.
  7. All tube?
    Anyway, you should be all set then! Have fun....
  8. Primary

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    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

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