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.

    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 (June 16, 2023 at 8:58 PM).

    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.

    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"