Ohm math question

Discussion in 'Amps and Cabs [BG]' started by Sidecar666, Apr 3, 2005.

  1. Sidecar666


    Mar 27, 2004
    Anyone know which speaker jacks I should plug into for a 3.2 ohm load? My Mesa 400+ has an 2-8's, 2-4's, and 2-2 ohm jacks. I have a 4 ohm cab and a 16 ohm cab. Togehter, in parallel (that's how the Mesa does multiple cabs), they make 3.2 ohms. Which jacks would I plug the cabs into? the 4 or 2 ohms?
  2. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    my guess is the 2 ohm jack

    unlike ss amps, tube amps don't like impedances above what they're expecting as it raises the plate voltage.

    overall, most tube amps are somewhat safe with a 100% mismatch either way, and you're kind of smack in the middle.

    more to the point, i doubt you're going to get much of a volume increase by adding the 16 ohm cab, it's only going to get 1/4 of what the 4 ohm cab will be getting. do you really think it'll be worth using it?
  3. Daytona955i


    Feb 17, 2005
    Albany, NY
    Put it in the 4ohm. Real impedence, and rating are very different. 2 Ohm's is too much current to give to a 3.2 ohm load, go a higher number of ohms, or a lower current.
  4. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    Wait a tick. What 16 Ohm cab do you have? And what is the 4 Ohm one? Perhaps we can rewire the cabs to have a more even impedance.