Low frequency feedback

  • Hi! Playing through Kemper power stage, seymour duncan powerstage 700 and two kabinets, there is a low "bass" frequency feedback rising up whenever I stop playing.

    I noticed if the volume is lowered then it doesn't happen so often. I don't play too loud, but more volume was necessary. The point is, it wasn't too loud and there should be no low frequencies feedback.

    The low cut output frequencies are already cut to 100Hz (though maybe it doesn't work for the monitor output and only works for the main output, now I'm not sure about it).

    Really don't understand why that low feedback happens, never before happened. Any help will be truly appreciated.


  • There's so many things it could be. I would start looking at cables. I've bought new ones that started picking up RF after 2 months of use. One thing I would do is step on and roll the cables under my foot to see if it the noise would come and go.

  • Is it strings that starts to vibrate ? Try to mute with hand.

    Is it "bad" pups ? Turn the volume down on guitar.

    Does the feedback appear in different locations or only

    in one specific room ? Acoustic treatment needed ???

    Any FX´s with extreme settings activated that start to self oscillate ?

    Just a few thoughts :/

    Cheers !

  • Thanks all of you for your kind suggestions, I've double checked everything you mentioned, I had already previously checked out some of those items, but I stil haven't got a clue why it happens.

    Guitar is a PRS custom 24 USA, cables are high class cables but just in case I also changed them, no extreme settings, noise gate on, "low" feedback appears in no specific location, with any performance, and so on. I noticed that maybe it happens when the volume in the Seymour Duncan powerstage 700 (SDPS) reaches 12am position, so I'll try to increase kemper stage monitor output (mostly around -18 or -20) and low SDPS volume below 12am.

    I'll keep on investigating, once again: let me thank all of you for your kind support! ;):thumbup:

  • can you make a short video of the issue to let us hear exactly what type of noise we are talking about?

    you need to figure out if it is a physical acoustic problem (guitar feedback, room resonance etc or an electrical problem.

    is it happening at home or is this an on stage issue?

    Do you have anything else in the signal chain? I used to get a problem has did many others) when running a delay in the Fx loop of a Mesa Dual rectifier. The cause was a little parallel signal bleeding through and sending the delay into self oscillation. Sometimes the cause can be found in the least expected places.