High/Low Pass Filter either in Studio EQ or single FX block

  • I've read the previous threads on it and know that ckemper himself has said he sees no use for it and that he doesn't think steep curves are the way to go about shaping a guitar tone, but I 100% disagree.


    I have yet to mix a record where the guitar sounds better without a HPF around 80hz and LPF at around 13khz, usually around 24db/oct steepness. I know tons of live engineers who default to even greater extremes like 120hz/5khz on the desk. Granted I'm speaking primarily in regards to high-gain rhythm guitars in a metal/hardcore setting, but this is something I do regularly and something I have really tried to replicate via the wah hpf (takes two FX blocks just for filters) and the eq low/high shelves turned way down, but when either blind or viewing a frequency analyzer I cannot replicate the same dramatic cutoff on each end that results in what I find to always be a more natural sounding, better fit for the mix, less battling with the vocals guitar tone, despite the unnaturalness of the processing.


    That's just one use case - now that you can blend a DI in with the amp feed for a common DI + amp bass rig, why wouldn't you want to be able to hpf the crap out of the amp signal? I very, very frequently run bass tracks through a guitar amp to get a really nasty sounding grit on it, but then filter out below 800hz or so to keep it from muddying up the low end; to be able to do this right in the KPA would be amazing!


    There seems to be this kind of "I can't see a legitimate use-case and/or it wasn't designed that way, so your feature request is invalid" mentality around some of requests on here (dly/verb fx before amp block comes to mind) that can be really frustrating as a user. That said, I have 2 very legitimate use-cases outlined here that are both 100% possible in nearly ever other amp simulator at/near/below the KPA's level (AxeFx+Axe2, Eleven, PODxt), and I sincerely hope I'm not alone in thinking this isn't a ridiculous feature to ask for.


  • I guess I have never said anything against steep curves :)


    However, the LPF and HPF in the Profiler are 24 dB/Okt, as you desire.
    I cannot tell why you have not reached the desired result, as there might be no technical reason for that. Would a Hertz scale for the Manual control help?


    I did another test: I tried to match the sound of the 24 dB Highpass Stomp with the Low band of the Studio EQ (set to -12 dB).
    I have got a perfect match in a minute.


    It is not easy to comprehend that so many people state that the EQs don't do this task.
    However, there is a difference between the HPF and a shelving eq for that task: you will have to dial a different Hertz value to achieve the same effect, if you go by number and not by ear.
    Might that be the problem?




  • Ckemper, what I'm doing in this case is looking at an EQ plugin with a built-in spectrum analyzer (DMG Audio's Equality) and comparing the stock hpf/lpf in the plugin (variable slope/frequency, true filters) to the high/low shelf on the Kemper set to -12db and changing the hz to try to get as close as possible to the same cutoff curve as I can with the filters in Equality. I can get close, but it's not the same; even at -12db, there is enough sub-low and 'air-like' top end making it's way through and it definitely effects the tone.


    If I use the studio EQ shelves to roll off low end, by the time I'm getting rid of all the sub-lows I want, I'm at like 300-400hz on the dial, when I want to be closer to like 120hz.


    I think the real issue with shelves vs filters is that the shelves only go to -12db; I want to go to minus infinity at the same slope.



    A Hertz scale for the Manual control on the Wah filters would help, but it doesn't solve the problem of having to use two FX blocks to get an HPF/LPF combo going - this means that EQ + filters is taking up three entire blocks, leaving me only one remaining post-amp block.

  • This is what I did:


    I dialed the factory rig "Sabbath"
    I have put a Studio EQ on X, LowGain at -12 dB, LowFreq at 100 Hz.
    I would estimate the equivalent high pass frequency at about 140 Hz.


    Also I have put Wah HighPass on MOD, Manual to 1.6 (coming from 1.7), PedalMode off.
    I played a 7-string guitar.
    When I toggle these two effects there is no audible difference that would show the need for a HPF to cut boomy frequencies from an amp sound.


    You said, you were "looking at an EQ plugin with a built-in spectrum analyzer". A spectrum analyser will show different pictures, for sure.


    I have listened by my human ears for this test, no spectrum analyzer. But maybe this is not the right approach. :)


  • I appreciate you testing like this and posting; if there's no audible difference between those two, that's wonderful, but having a single filter inside an FX block with the wah controls is an unacceptable workaround to me because it leaves you with only 1 block for wet FX after you're done.


    That said, I don't hear the same thing you do when I'm listening on my monitors and in a mix. If I have to post a/b clips then I'll find some time to do that, but right now without using up 2 extra blocks I can't do the HPF/LPF stuff I usually do, and being able to have that in the tone itself instead of a plugin would be great.


    The biggest issue here is UX - it's a horrible user experience to be told to deal with some janky workaround because there "isn't an audible difference" despite it being a repeated, popular request and a standard feature on other products on the market.

  • That's absolutely not the case, though - the low shelf set to -12db doesn't remove as much low end as a true HPF would. There is no way to roll off enough of the sublows at -12db without eating into the useful low end of the guitar signal (I don't want to be filtering up to 200hz just to get all of the crap at 80hz out of the mix).


    In any case, the real problem is with the top end! I want to filter off after 12khz because it's usually just gross, ratty top end, and I can push more highs into a tone if I'm removing that nasty fizz with a filter. But -12db on the high shelf still doesn't do this; the point at which the fizziness is removed makes the tone too dark to use because the rolloff point has to be set far lower than 12khz to get rid of the stuff above it.


    It seems like you either don't believe that I'm having an issue or assume that I'm doing something wrong - is this accurate? I don't know how to make my request any more clear; given the current EQ and Wah controls, I cannot get HPF/LPF effects to my liking. As such, I am requesting that we're given actual filters to control and feel like I'm being ignored or brushed under the table as someone complaining about a non-issue.

  • Since it's very common to use extreme low/hi cut curve and dB settings when mixing I think it would be good to implement this so the kemper can copy those settings many are used to. Many have requested this feature.


    Jeff, I think it would be great if you could post two images of your freq analyzer, one using the DMG eq plugin settings, and then the kemper eq settings needed. That would demonstrate the differences. Using our ears is always important but in some cases a freq analyzer can pinpoint in extreme detail what the ears can't do in a similar way.

  • Since it's very common to use extreme low/hi cut curve and dB settings when mixing I think it would be good to implement this so the kemper can copy those settings many are used to.


    Jeff, I think it would be great if you could post two images of your freq analyzer, one using the DMG eq plugin settings, and then the kemper eq settings needed. That would demonstrate the differences. Using our ears is always important but in some cases a freq analyzer can pinpoint in extreme detail what the ears can't do in a similar way.


    I'd be happy to post screenshots later tonight; it's obvious what you see. The reduction in low end is great until -12db, where the low shelf bottoms out; after that point you get a ton of sublows still coming in, albeit quieter. It's better than nothing, but there's still a lot of low end bouncing around that I'd rather kill entirely (especially if I'm trying to filter before the amp to tighten up my pickup, for instance).

  • I think high and low pass filters would be pretty useful. In studio applications it's easy enough to just use a plugin to get rid of the extremes but it would be nice to save the filters for live use.. I tend to agree with JeffTD that shelving eq's are at best an inelegant workaroud when you really just want a filter

  • @JeffTD Hey man, long time!.


    Just to chime in, whilst I think LPF/HPF will be useful, but surely if your mixing/tracking you would do that at post, or on the desk. not via the source...I understand getting the source right to begin with is ever more important. but to filter to such degree could be bad, especially in the wrong hands. - IF its for live use, then the Studi EQ works great for this at certain freq Pre & /or Post. but for your own monitoring, if it goes to FOH desk then they will filler there anyway. - Im not really sure I'd agree that its needed.


    You seem to know what your talking about, and I apologise it I dont understand, but why are you needing them in the Kemper and why not use it at tracking stage via desk/DAW?

  • That's absolutely not the case, though - the low shelf set to -12db doesn't remove as much low end as a true HPF would. There is no way to roll off enough of the sublows at -12db without eating into the useful low end of the guitar signal (I don't want to be filtering up to 200hz just to get all of the crap at 80hz out of the mix).


    In any case, the real problem is with the top end! I want to filter off after 12khz because it's usually just gross, ratty top end, and I can push more highs into a tone if I'm removing that nasty fizz with a filter. But -12db on the high shelf still doesn't do this; the point at which the fizziness is removed makes the tone too dark to use because the rolloff point has to be set far lower than 12khz to get rid of the stuff above it.


    It seems like you either don't believe that I'm having an issue or assume that I'm doing something wrong - is this accurate? I don't know how to make my request any more clear; given the current EQ and Wah controls, I cannot get HPF/LPF effects to my liking. As such, I am requesting that we're given actual filters to control and feel like I'm being ignored or brushed under the table as someone complaining about a non-issue.


    +1
    I am hearing and finding the same thing, not in studio situation but when playing loud with my band on a DXR10 monitor.
    HPF and LPF filter in a single slot would be a great enhancement.


  • You seem to know what your talking about, and I apologise it I dont understand, but why are you needing them in the Kemper and why not use it at tracking stage via desk/DAW?


    @and44 I want to get it right at the source because I want to get it right at the source - I know what I'm doing with tones and have very specific things in mind, so when my Kemper turns out to lack very basic tools that I need to use to achieve those goals, it's frustrating. Yes, I could do this on my gtr bus or have the FOH guy do it, but I'd prefer if I could track with the tone in mind without having to resort to software monitoring via the DAW to achieve it.


    That, and the previosuly mentioned use of filtering off top-end fizz to boost more useful, clean high-end into the tone is HUGELY useful and something I want to do more often at the source.


    Looks like I've got my weekend sorted out - comparing clips of the shelves trying to act as filters, the wah filters, and actual EQ filters.


    @ckemper, what I'm mostly saying is that regardless of whether or not the Wah filters get me the sonic results desired (I haven't tested thoroughly; I'm against the concept of using them and the controls aren't intuitive for this purpose), I think it's insane that you want me to use two FX blocks just to get HPF/LPF features that should just be included in the studio EQ itself. All IMO of course; it looks like I'm not alone in that desire, though.