Help boomy passive FRFR

  • Hello gents first post! Just took ownership of a powerhead specifically to use with a Matrix FR212 I have so I wouldn't have to get a separate power amp. The frequency range is 55-20khz so it has some extended lows and highs making profiles sound boomy and scratchy. It's also ported adding to the boominess.


    With my old fractal I was able to adjust the high/low filter and the cab resonance to dial it in nicely but how do I do this with the kemper? I've added a studio eq and adjusted the high/low pass filter to 100/8k which had helped some but I was wondering if there's anything else I can tweak similar to the cab resonance in the fractal or something else I can try to tweak?

  • do you have the profile speaker turned off in the monitor output

    why That ?

    that its an FRFR Cabinet which should be used with studio Profiles including Speaker Section,

    only when you play thru a Guitar Cab , Speaker Part should be turned off

  • Welcome to the forum :)

    Try this : press and hold the "Cabinet" button, turn "High Shift" and "Low Shift"

    and see ( hear ) if anything changes to the better :/

    The adjective for metal is metallic. But not so for iron ... which is ironic.

  • Thanks for the tips and warm welcome!


    So the main and monitor output eq had the bass bumped up to +5 so I set everything to 0 which seemed to help some.


    Raising the low shift in the cab section made a significant difference in tightening things up! Anybody know exactly what these shifts are doing? Will they have a negative impact on profiles?


    Should I turn off the studio eq now or use these settings in conjunction with? Any other tips?

  • From the manual:


     High Shift, Low Shift

    Both parameters influence the characteristic formants of a Cabinet PROFILE, thereby simulating a change in size. “High Shift” will make the higher formants more prominent, whereas “Low Shift” does the same for the lower frequencies


    There's a great tutorial from tonejunkie about low/high shift controls on YT. I'd suggest watching that (+ a few others on definition etc). Very handy videos!



    Yup read it/watched it. I guess I was looking for more of an actual frequency spec or range of shift. But I get what it's doing now.

  • Thanks again for all the helpful responses, much appreciated!


    However, I made a new discovery... I switched to an outboard analog power amp (effects return), through the main out of course, and the sound was much better. I'm thinking maybe I just don't like the built in power amp of the kemper with my cab?

  • I agree... I'll have to do some experimenting. I'm thinking it's still good to have the power amp version just in case I want to plug into a real cab at some point.


    Thanks again for all the help guys!

  • A ported speaker is gonna boom, it's what they do. Set up a Studio EQ stomp, the factory one called "No Boomy E A" would be a great place to start. Work with the EQ to find the offending frequencies and dial them down. Then set Hi and Lo cut to preference, think mine are set at around 80hz and 10k but not sure, Hope this helps.

  • A ported speaker is gonna boom, it's what they do. Set up a Studio EQ stomp, the factory one called "No Boomy E A" would be a great place to start. Work with the EQ to find the offending frequencies and dial them down. Then set Hi and Lo cut to preference, think mine are set at around 80hz and 10k but not sure, Hope this helps.


    That makes sense. I think Matrix's idea was to make it have the bottom end of a 4x12. I did set up a studio eq but just went with the first one that came up in the list and only adjusted the hi/low pass so I probably still have some frequencies set incorrectly. I will try out the No Boomy one and see if it helps.