4 x 12 Cabinet Question

Discussion in 'Amps & Cabs' started by DaveInSoCal, Sep 10, 2018.

  1. DaveInSoCal

    DaveInSoCal Member

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    Hey!

    I just bought an old Genz Benz GB412SL on Craigslist.
    I'm not real experienced with heads / cabinets so I need a little help here.

    The cabinet has a small sticker that is marked 8 ohms and 2 unmarked Jack's.
    I ohmed them out and each one is 4 ohms. So I'm guessing this is stereo? Each jack drives 2 speakers I assume. There is no mono input as far as I can tell.
    This being the case why is it marked 8 ohms??

    Can I safely drive the amp with the two 4 ohm outputs from my head?

    I dont want to damage my head, any advice is much appreciated!!
     
  2. Clifdawg

    Clifdawg Well-Known Member

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    It depends. What kind of head do you have? If you have 2x4 ohm outputs, I suspect it's a parallel output where the total load must equal 4 ohms. In other words, you can connect one 4-ohm cab to it or two 8-ohm cabs to it.

    I couldn't find the SL on the Genz Benz website, but under discontinued products, I found a "GB412G-Flex," which states that it has a handling on 300 watts at 8 ohms mono or 150watts per side at 4 ohms stereo. I am assuming your inputs are similar, but if you only have 2 jacks, maybe it only works to stereo... Which means you might have to do some wiring yourself or just run two of the speakers through one output.
     
  3. Paul G.

    Paul G. Well-Known Member

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    The cabinet is has four 8-ohm speakers wired in series parallel. The 8 ohm jack runs all 4 speakers in mono. The other 2 jacks drive 2 speakers each @4 ohms (parallel). So, if your amp is an actual stereo amp with discrete outputs, you use those with your 4 ohm output. Alternatively, you can use the cab with 2 heads.

    Of course this is ridiculous, most guitar heads have one output transformer so, plug into the 8 ohm using either the 8-ohm jack, or setting the switch to 8 ohms. There is no reason in the world to complicate things by running multiple wires for a single signal.
     

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