Is 4 ohms louder than 16 ohms?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by TheGuildedAge, Jan 29, 2008.


  1. TheGuildedAge

    TheGuildedAge Supporting Member

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    I am sure this has been covered, but I can't find an answer. If I rewire my 4 ohm cab to 16 ohms, will there be a volume change?
     
  2. JubileeMan 2555

    JubileeMan 2555 Member

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    There would be no volume change IF the amp you are using is switchable from 4ohms to 16ohms. if you had a fixed 4ohm out from your OT then your volume would obviously decrease because it would be feeding into a much higher resistance.
     
  3. TheGuildedAge

    TheGuildedAge Supporting Member

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    Thanks. The amp has 4, 8, and 16 ohm jacks.
     
  4. JubileeMan 2555

    JubileeMan 2555 Member

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    Then it should be the same dB.

    Some do argue that certain amps sound better at different ohm settings, but I think that has to do with the output transformer's reaction in the circuit. Not to mention I haven't heard any clips or proof it makes a difference.

    T.
     
  5. rooster

    rooster Member

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    This is not as easy of a question as you might think. The optimal power transfer will occur at point "x", where point "x" is the optimum impedance for that power section at that voltage. Any deviation from this point, whether an increase or a decrease will decrease efficiency. Most output trannies/output sections can handle a bit of a mismatch, and the rule of thumb is to not go beyond 50% either way. That is, if you plug a 4 ohm speaker load into an 8 ohm output tap, you probably won't blow up your amp, nor will a 16 ohm load. It will, however, change the tone of the amp. In some cases, it WILL blow up your amp, depending on how close to the edge the amp is designed, and how hard you're driving it.

    This is NOT a question with solid state amps, in most cases they can take any load with a higher impedance than their lower limit. However, tube amps don't work that way, they have a matching transformer as well as the actual tubes pulling the current through it. Your safest bet is always to use the recommended tap with the speaker load you're running. Cheaper that way, with what repair costs are running.

    rooster.
     
  6. TheGuildedAge

    TheGuildedAge Supporting Member

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    I currently run the amp at 4 ohms into a 4 ohm cab. I was going to rewire it to be a 16 ohm cab.
     
  7. cameron

    cameron Member

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    You probably wouldn't get a noticeable volume difference, but there might be some change in sound.

    A similar question was asked a while back in this thread: http://www.thegearpage.net/board/showthread.php?t=334351

    As usual there's a mix of good and bad info in there. Skip to the end where John Phillips weighs in on how and why one wiring config might sound different from another.
     
  8. TheGuildedAge

    TheGuildedAge Supporting Member

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    Thanks, I was looking for that and just got tired of searching.
     
  9. donnyjaguar

    donnyjaguar Member

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    All else being equal, 16Ω will be slightly louder. Reason being there are simply more turns on the 16Ω secondary so its reasonable to expect the coupling efficiency to be better.
     

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