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Matching speaker Ohms and amp Ohms

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  • Matching speaker Ohms and amp Ohms

    Hello there!
    I will be the owner of a mesa mk iii 100 watt head in a couple of days. My problem is that my 1x12 cab has an 16 Ohm speaker and the amp has outs for 8 and 4 Ohms.
    Is it safe , for a temporary solution, to connect a 16 Ohm resistor of some kind parallel to the speaker and then connect it to the 8 Ohm out? If so, what kind of resistor would you propose?
    Also, the speaker says it can handle 60 watts; could I run the amp through it at low volume or should I just flip down the half power switch and keep it there?
    Thanks in advance.

  • #2
    If you run the amp on half power and connect the speaker to the 8 ohm jack you should be fine.

    you may get a few different answers on this


    • #3
      this is verbatum from their Mk III user manual:

      One 8-ohm and two 4-ohm jacks are provided. The Boogie is not very sensitive to speaker mismatches and will not be damaged by
      them except that very low ohmage loads will cause the power tubes to wear out faster.
      A single twelve-inch 8-ohm, speaker should
      generally be connected to the 8-ohm output on the amp. When using two 8-ohm speakers, connect them both to the 4-ohm outputs
      provided (because the total load is 4 ohms in that case).
      4x12 cabinets may be 4, 8, or 16 ohms; if you are not sure of the impedance of your cabinet, you may need to remove the rear panel to
      see what ohmage the individual speakers are. Most Marshall 4x12 cabinets are 16 ohms. By wiring all four speakers in parallel, you
      can reduce the cabinet impedance to 4 ohms (assuming the speakers are 16 ohms each). A MESA/Boogie 4x12 cabinet comes
      standard at 8 ohms. It has four 8-ohm speakers wired in series-parallel. No matter how unusual your speaker setup, it's always
      possible to get good performance. If you need two 8-ohm speaker jacks (in order to run two 16-ohm cabinets at the same time), you
      can either use a Y-box, or daisy-chain the cabinets, or even rewire the speaker lacks inside the amp so there are two 8's and one 4.
      (You should then re-label the rear panel to avoid confusion later.)



      • #4
        No Resistor

        Ohms for speaker Impedence and Ohms for resistance are 2 different things. Do not add a resistor to it The fact that you have a 16 ohm speaker means that it will take more power to drive it than a 8 or 4 ohm speaker. You could drive that 16 ohm with the 100 watts if you wanted to, you won't hurt the amp ( as long it is a tube amp and I think that model is) , the only thing that will be at risk is the speaker itself and I think that won't be an issue either.