Using 2 amps with one 4x12 cab

Discussion in 'Amps and Cabs' started by Drown, Jun 19, 2008.

  1. Drown

    Drown Member

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    Hi there,
    I´d like to use my Rectifier and the Randall at the same time with one 4x12 cab. The cab has only one 16 ohms input jack and the amps are switchable between 4, 8 and 16 ohms. The amps should run at the same time. What do I need for that? Or isn´t it possible?
     
  2. dk123123dk

    dk123123dk Member

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    you need to rewire the cab. Google speaker impedance calculator to figure out how to wire it properly. Some cabs have a switch to got from a mono cab with two inputs in parallel, to a stereo cab with an input for R/L. Check for schematics for a similar cab.

    Good luck.

    dk
     
  3. SatelliteAmps

    SatelliteAmps Member

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    You can't run both amps at the same time into the same 4 speakers. You need to rewire the cabinet as two 2x12 cabinets, and run each one separately to each head. Or you can purchase a Radial Headbone and be able to switch between running either head into the cabinet.
     
  4. Gary

    Gary Member

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    Satellite is right. I ran a couple heads into one 4 x 12 cab back in the 80's. I had to add a jack to the back panel. Wire 2 speakers to each jack, and you're good to go. Add in an ABY switch and you can use the amps/cab any way you want. Very simple to do, good luck, Gary
     
  5. jerseydrew

    jerseydrew Member

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  6. Gary

    Gary Member

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    I hope I didn't confuse him!!! Like I said, I did this over 20 years ago, no radial switchbone was needed, or even made at that time. Just wire 2 speakers to one jack and 2 speakers to another jack, ( I had to add a jack on the back panel of my Marshall 4 x 12 ). I'm no expert, so I could be wrong though. I ran one head for rhythm and then just kicked on the ABY to activate the other amp for leads. Maybe I just got lucky that nothing ever went wrong?? It seemed very simple to me. If I'm passing on bad info, please correct me, no harm intended here. Take care.
     
  7. gtrnstuff

    gtrnstuff Member

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    You're fine, I think he was reading too fast and didn't catch where you separated the speakers into 2 2-12 groups. Doing that is no prob.
     
  8. Troubleman

    Troubleman Silver Supporting Member

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    Radial Headbone. Problem solved. Amazing company, very high-quality products

    jb
     
  9. FJTurner

    FJTurner Member

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    +1 !!!
     
  10. meterman

    meterman Member

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    Any load issues withe Headbone? The thought of running an amp flat out and then switching it to a dummy load makes me nervous....I like the idea of two separate 2x12 configs in one cab but I guess then you have to compromise on speakers/handling and never get the full effect of the 4x12....
     
  11. guitardr

    guitardr Silver Supporting Member

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  12. beej

    beej Supporting Member

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    Sounds like the OP wants to play through both amps simultaneously though and not switch. In that case he'll have to re-wire the cab to use each side separately.
     
  13. Drown

    Drown Member

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    Thanks for the many responses.
    So I guess rewiring the cab or buy a second one are my only choices if I want to play both at the same time.
     
  14. trey85stang

    trey85stang Member

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    the headbone isnt needed. Just rewire the cab into a stereo cab, parallel each two speakers for an 8ohm load.

    I dont know why the headbone keeps getting plugged in this thread... each amp will have a load if you rewire it to stereo and hook each amp up to the two inputs.
     
  15. JimH

    JimH Member

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    Yes this is correct, you can't have both amps on, both through the full 4x12.

    ...it's either rewired and then both on simultaneously becomes an option - because you just ABY the inputs and both amps are always on (and plugged into their 2x12 cabs) all the time. Or the head switcher switches the entire load of one amp to the cab and the other amp to a dummy load -all on the fly. But both can't remain attached to the speaker simultaneously.
     

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