Bug in the Kemper cab / stack section

  • Kemper support did answer today: They say it is a bug.


    They can not tell how long it will take, but they'll seek to address this problem as soon as possible and ask for patience.


    Patience ... not one of my strenghts ;)
    This is quite a big bug in my opinion and concerns a basic function. Tone is directly affected...


    And what is not clear to me, if in general the cab section is affected (changes tone) dependent on the loaded amp section? So changing cabs in the Kemper would be a total different approach to what I know from other devices. And a specific "favourite" cab copied to other profiles or the use of converted IR would have to be seen in a completely new light?! Anyone with insight, how amp and cab section really "interact" here?

    Edited 2 times, last by Ibot39 ().

  • It is a huge bug, but I'm very glad that they have it recognized as such, and have committed to addressing it. I was fearful, as were you, that it was possible that it's "just how it works". Glad to see that that is not the case.

    Disclaimer: When I post demo clips for profiles, there will be some minimal post-processing, unless stated otherwise. I normally double-track hard L/R, and add to the main buss a small amount of EQ and a limiter/comp set pretty light as well. Sometimes I get test profiles in advance of release, though 90% of my clips will be from packs I have purchased.

  • Nice to have it recognized. It's a tricky one though since fixing it very well could affect the sound of existing rigs.

    Kemper PowerRack |Kemper Stage| Rivera 4x12 V30 cab | Yamaha DXR10 pair | UA Apollo Twin Duo | Adam A7X | Cubase DAW
    Fender Telecaster 62 re-issue chambered mahogany | Kramer! (1988 or so...) | Gibson Les Paul R7 | Fender Stratocaster HBS-1 Classic Relic Custom Shop | LTD EC-1000 Evertune | 1988 Desert Yellow JEM

  • I'm not sure if this will help and obviously it's now on the to-do list but, In general when I'm auditioning profiles, one of my go to things I do is switch to a small list of my favorite cabs saved as presets as a benchmark test for the profile of the amp section. I also have groups of stomps and effects presets I use in this way as well.

  • I'm not sure if this will help and obviously it's now on the to-do list but, In general when I'm auditioning profiles, one of my go to things I do is switch to a small list of my favorite cabs saved as presets as a benchmark test for the profile of the amp section. I also have groups of stomps and effects presets I use in this way as well.

    I do the same thing...but if I understand this problem correctly, this is quite a glitch in The Matrix for those of us who take that approach...or for switching cabs at all, isn't it?


    I mean, if it works, it works, and this method does work well, so there must obviously be consistency on some level. And if it sounds good (and it does), it doesn't bother me a lot. But I'm very interested to follow the issue.

    Disclaimer: When I post demo clips for profiles, there will be some minimal post-processing, unless stated otherwise. I normally double-track hard L/R, and add to the main buss a small amount of EQ and a limiter/comp set pretty light as well. Sometimes I get test profiles in advance of release, though 90% of my clips will be from packs I have purchased.

  • Kemper did introduce merged profiles for a reason - to ensure, that the amp part of profiles sounds right when an external cab is used.


    Sidenote with reference to the topic: Some commercial sellers do "merged" profiles that are not merged (as far as I know). In reality they just make direct profiles from an di box. Then they just COPY a few existing cab parts (from other profile session with other amps) to the direct part, save that rig and call it merged. I don't deny that those rigs may sound "good", but this is not how to get the most accurate, authentic result. Because the cab part for example was taken from another amp (different power amp, speaker....interaction), the Kemper merged process is not possible - as said: It's just direct amp part and any cab part SAVED.


    Real merged means: Making a studio profile. Then making direct amp profile from di box with SAME amp settings and SAME cab connected. Then copy the cab of the studio profile to the corresponding direct amp profile, checking merged process option in the kemper and store that. Repeat all steps when changing ANY setting or part for every profile.


    I think merged does ensure authentic amp part, but not "authentic" cab part or "correct" interaction as soon as changing it. As soon as cab part is copied to another amp part (studio or merged) you don't get the initial (and profiled) interaction, but some calculated (?), modelled (?) interaction - of course!


    Or is it different? Maybe some officials can shed some light on this?

  • Indeed, Tobi; I'd be keen to hear what Mothership has to say.


    Also, I'd like "authentic" merging to be mandatory for any vendor who's done what you claim some have.


    The only way I can think of that the K Team™ could ensure this is to honour a request we made about a year ago - for the OS to label "authentic" Merged Rigs as such with some sort of uneditable tag or flag on the main Rig screen.

  • Indeed, Tobi; I'd be keen to hear what Mothership has to say.


    Also, I'd like "authentic" merging to be mandatory for any vendor who's done what you claim some have.


    The only way I can think of that the K Team™ could ensure this is to honour a request we made about a year ago - for the OS to label "authentic" Merged Rigs as such with some sort of uneditable tag or flag on the main Rig screen.

    I have no problem with "construction kit" profile packs - but vendors should not call it merged. I could name a few sellers - quite a few! More than vendors doing real merged.


    It may sound good and work and be easier and bla bla - but it is NOT merged when a few "proven" cabs are just copied to new direct amp profiles. Strictly speaking, it is not "all merged", when there was at least made one or two real merged rigs for a pack and then again the same cabs copied to different gain stages.


    But as soon as the cabs are copied to different amps, we are leaving the "authenticity" behind a bit. Or not that much?

  • Well, different mic placement and so on tells me it's a different kettle of fish and not the "real" thing, so to speak.


    The cab component is more than an IR, as we know, so the behaviour captured is specific only to a particular cab and the mic model, placement and signal chain used at the time.


  • .


    Real merged means: Making a studio profile. Then making direct amp profile from di box with SAME amp settings and SAME cab connected. Then copy the cab of the studio profile to the corresponding direct amp profile, checking merged process option in the kemper and store that. Repeat all steps when changing ANY setting or part for every profile.

    are you sure that would give a true merged profile?


    I could be wrong but it doesn’t sound like that would be any better than just turning of the cab section of any studio profile: and possibly worse.


    Here’s my logic but, as I say, I could easily be wrong:


    KPA doesn’t know exactly where amp comtribution ends and speaker begins so estimates the break point. It seems to do a very good job in this regard but it isn’t totally accurate. Therefore, using a cab portion of a studio profile should still have the same estimated speaker/mic response but coupled with actual DI amp contribution.


    My thinking is that the only way to create a proper merged profile would be to a) make a DI amp profile then b) make a standalone cabiner IR and upload into Kemper and finally c) merge the two.


    Am I wrong on this one?

  • Yeah Alan.


    The critical piece of information you're missing is that the Kemper compares the DI Profile with the studio one, meaning that it can "subtract" the DI Profile's data from the Studio's, the result being the cab info alone, thus determining exactly where the amp ends and the cab begins.


    The issue Tobi and I have is that you can't go and grab a cab from a Studio Profile made on a different day, with a different signal chain and hooked up to a different amp, combine that with another DI Profile made of a different amp in differing circumstances and call it a true Merged Profile; the Kemper will execute the "subtraction / differentiation" routine, but you'd be giving it "false" data to begin with - data gleaned from two different situations, if you will.

  • Your assumption is wrong. Please read the main manual where the procedure to create merged profiles is explained in great detail. In a nutshell the optimal approach is to create a studio PROFILE and a direct amp PROFILE and the copy the cab part of the studio PROFILE and paste it into the cab module of the direct amp PROFILE to merge them. While converted IRs can be used they will lack the complex impedance interaction between the cab and the power amp of the reference amp that were used in the profiling session.

  • Your assumption is wrong. Please read the main manual where the procedure to create merged profiles is explained in great detail. In a nutshell the optimal approach is to create a studio PROFILE and a direct amp PROFILE and the copy the cab part of the studio PROFILE and paste it into the cab module of the direct amp PROFILE to merge them. While converted IRs can be used they will lack the complex impedance interaction between the cab and the power amp of the reference amp that were used in the profiling session.

    Exactly. And when a cab is copied to another direct amp profile of another amp instead of repeating the process, it's not the "authentic" interaction anymore - and is not a merged rig anymore.


    Still not answered: Is the cab section in general dependent on the used amp part? Does the same cab sound different or react different when used with another amp section (in contrast to a simple IR loader)? Is there some sort of "calculated" interaction going on?

  • no chance-i am bold!;-)

    LOL Yeah, I could tell all those years back from the Roland Big Brass Ensemble ROM board demo you did that you're bold... and super-talented, brother. You remember the one? The 4-on-the-floor "happy" pop piece with the snappy section lines?


    Well, I said that we were talking more about the issue of the Kemper's being able to differentiate between the cab and amp when the cab is stolen from an unrelated Studio Profile. Alan couldn't see how it could do this 'cause he was missing the "subtract the DI Profile from the Studio one / compare them mathematically" thing, which is why he brought up IR's as a possible means of getting an untainted cab into a Merged Profile; he could see no other way.


    There. Hairs split. Smoke blown up ass and tyres fully inflated, so you're good to go, HJ. :D

  • LOL Yeah, I could tell all those years back from the Roland Big Brass Ensemble ROM board demo you did that you're bold... and super-talented, brother. You remember the one? The 4-on-the-floor "happy" pop piece with the snappy section lines?
    Well, I said that we were talking more about the issue of the Kemper's being able to differentiate between the cab and amp when the cab is stolen from an unrelated Studio Profile. Alan couldn't see how it could do this 'cause he was missing the "subtract the DI Profile from the Studio one / compare them mathematically" thing, which is why he brought up IR's as a possible means of getting an untainted cab into a Merged Profile; he could see no other way.


    There. Hairs split. Smoke blown up ass and tyres fully inflated, so you're good to go, HJ. :D

    i sure remember that. Actually that song ended up on one of my CDs but using a real brass section.

  • Exactly. And when a cab is copied to another direct amp profile of another amp instead of repeating the process, it's not the "authentic" interaction anymore - and is not a merged rig anymore.
    Still not answered: Is the cab section in general dependent on the used amp part? Does the same cab sound different or react different when used with another amp section (in contrast to a simple IR loader)? Is there some sort of "calculated" interaction going on?

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