Running 4 cabs???

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by lookslikemeband, Dec 26, 2004.

  1. lookslikemeband

    lookslikemeband Member

    Messages:
    576
    Joined:
    Dec 23, 2004
    Location:
    CO
    Hey gang -

    With my current rig, I run two amps (and A/B between them). I've got two Mesa 2X12's that I'd like to try to run on top of my Marshall 4X12's for a little extra "ummph".

    The Mesa's are wired for 8ohms, and my Marshalls can do 4/8/16.

    Can I run into the Marshalls on 4ohms, then parellel out to the Mesas??

    Any ideas??

    Thanks!

    Lance
     
  2. John Phillips

    John Phillips Member

    Messages:
    13,049
    Joined:
    Mar 17, 2002
    Location:
    Scotland
    Probably better to run the Marshalls at 16 ohms.

    You can't actually use them at 8 ohms unless you only want to run two speakers, which will defeat the point of wanting more 'ummph'.

    The sockets on the Marshalls aren't usable as in/outs - but the ones on the Mesas might be, I can't remember. So you need to go amp > Mesa > Marshall. Or, if the amps have two output sockets, simply run each to one of the cabs.

    Set the amps to 4 ohms if they have that option, or 8 if they don't. The true total impedance with a 16-ohm and an 8-ohm cab is 5.33 ohms, which is a safe mismatch from either 4 or 8 (if they're tube amps).

    2/3 of the power will go to the 8-ohm Mesa cabs.

    If you're absolutely sure the amp will take it, you could run the Marshalls at 4 ohms, then 2/3 of the power will go to them and 1/3 to the Mesas - it's still a safe mismatch from a 4-ohm output since it gives 2.66 ohms. You MUST set the amps to 4 ohms if you're going to do that. Don't try it with a solid-state amp.
     
  3. lookslikemeband

    lookslikemeband Member

    Messages:
    576
    Joined:
    Dec 23, 2004
    Location:
    CO
    Man... That is awesome! Thanks!

    For my current rig....

    I do have several outputs on my heads (they're Mesa/Boogie Dual Rectos. One is a Trem-O-Verb, for clean, and one is a Solo, for dirty). Do you know if it's safe to run cables out of the heads from different outputs??

    For example: Could I safely run a 4ohm output to the Marshall cabs AND an 8ohm out to the Mesa cabs??

    And yes, the Mesas are wired to be input/output jacks.

    Thanks again for all of your help!

    Lance
     
  4. John Phillips

    John Phillips Member

    Messages:
    13,049
    Joined:
    Mar 17, 2002
    Location:
    Scotland
    If they have two sockets and a selector (I think the T-Verb is like this, if I remember right?) it's safe to run two cables out of the amp. Set the amp to 4 ohms, whichever way you run the Marshall cab.

    If they're like the Solo and have two 4-ohm and one 8-ohm sockets, you can use the two 4-ohm sockets together, but NOT a 4 and the 8 at the same time... with one complicated exception:

    If you're with me so far ;) - you can run a 16-ohm cab from the 8-ohm socket and an 8-ohm cab from one 4-ohm socket at the same time. Since this is the combination you have, you may want to try it - you'll get slightly better power distribution between the two cabs.

    I think this may all be in the owner's manual for the amps... it is with mine (DC-5).
     
  5. lookslikemeband

    lookslikemeband Member

    Messages:
    576
    Joined:
    Dec 23, 2004
    Location:
    CO
    WOW! Thanks man!

    You guys here are AWESOME!!!

    I'm gonna try it.... If I blow up, it's been nice chattin!

    :D

    Lance
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice