Speaker Impedance Question

  • When the last beta version of the Kemper OS and Rig Manager I made my first attempt at profiling one of my amps. I wasn't very satisfied with the resulting profile and got to looking into my amp controls. I found that somehow the speaker impedance switch was set to 4ohms but the amp (Fender Machete) manual indicates it should be 16. I have no idea how it got switched to 4 but I changed it to 16 per the manual.


    My questions are these;

    Could leaving it at 4ohms damage the amp?

    How might this affect the profile?


    Thanks for what ever advice you may share.

    "Faith don't need no second opinion"

  • It is totally ok to run a 4ohm amp into a 16 ohm cab. The rule is that you can mismatch ohms as long as you mismatch with the speaker being a higher rating.


    If it’s reversed with the amp expecting 16ohms but getting 4…..that’s very bad. Like….smoke, flames….kablooey bad.


    You’ve done no damage.

    “Without music, life would be a mistake.” - Friedrich Nietzsche

  • Thanks, that's good to know.


    I'm a little embarrassed that I have been playing for 60 years and never learned about speaker impedance. I guess I just never needed to know. Another question I have is, if the amp says @4 ohms min total 50 watts and the speaker is 16 ohms, is it still 50 watts?




    "Faith don't need no second opinion"

    Edited 3 times, last by Edward Dixon ().

  • The amp will still put out 50watts - but the speaker will provide more resistance.


    My memory is a bit foggy on this next point - but I believe the only thing you'll notice is a bit of a volume loss when running the mismatch.

    “Without music, life would be a mistake.” - Friedrich Nietzsche

  • It seems like setting the speaker impedance switch back to 16 ohms allows me to turn the gain and volume knobs up a little bit without getting too loud. I just got a Kemper D.I. box and got a pretty decent profile with a fuller tone with no artifacts. I'm pretty sure the D.I. box made all the difference. I suspect the artifacts I got on the first profile was due to the impedance mismatch.


    I have eight more amps to profile but all should go smoothly from here on.

    "Faith don't need no second opinion"