Using the FX send for better cab seperation

    Hey,


    I tried to use the KPA with a power amp and guitar cab this weekend. Using some of the DI profiles gave decent resuls. But most of the profiles that were created using a cab/mic didn't sound very good when disabling the cab. I had a very "boxy/unopen" sound that I couldn't get rid of. Then this idea came to my mind:
    Why can't we use the alternative input for the preamp signal while profiling (additional to the mic)? You could use the FX send or even a DI box between speaker(s) and amp. With that additional reference signal it should be much easier to get a correct amp AND cab model I think. Would that be technically possible or would that collide with the digital alchemy ;-)?


    Cheers
    Daniel

    MJT Strats / PRS Guitars / Many DIY Guitars -- Kemper Profiler Rack / Kemper Remote / InEar

    AGREE 1000%!!! :thumbup:


    This is starting to become a BIG annoyance with the KPA.


    This needs to be addressed ASAP IMO.


    While the direct-to-board sound is stellar, the tone to a power amp/guitar cabinet leaves MUCH to be desired. I hate that the cabinet sound is still present even when you turn it off. As I have mentioned before, a "mix" option would be a win-win situation in my book. Then if you want the cab to flavor the sound a bit...you got it. If you want the cab entirely gone...you got it.


    God, I hope they fix this soon.


    I agree very much :) That's the most importand improvement I need now from KPA..


    Easier said than done.... I don't mean to rain on anyone's parade, but this is EXACTLY what those "other guys" were mentioning/asking about when the topic came up quite a while back on how you can successfully "split" an amps profiled preamp + power amp from it's profiled cab. I think the answer is, you cannot do it definitively. Did they ever mention how it's being done now? I know that most people assumed some type of subtractive EQ and that seems to make sense. But getting the split absolutely perfect and real world would be extremely difficult, no? And wouldn't it be slightly different depending on the amp, power amp, cab, speaker, etc... used for any given profile?
    There is so much interplay between the amp, power amp, cab, speaker that I can't see how it can be compartmentalized - that is the only downside to the profiling approach vs. the component style approach of modeling. What makes profiling sound so authentic is that is captures all those nuances between the amp, power amp, cab and speaker naturally.
    But maybe the approach Kemper users to this subtraction of the cab and speaker can be refined?
    Have you tried using a Direct out profile (loading down a tube head and line out into the KPA for profiling) and then replace the "cab portion" of that DI with another cab in the KPA? I did that using someone's Plexi DI profile and replacing the cab portion with a Tills Marshall 1960, it's in the music links section. What I'm thinking is that if I used that profile and disabled the cab on Monitor outs, it "should" get most of the meat an potatoes of the amp/power amp and very little to no cabinet. Not sure though.

    I think you've hit the nail on the head night runner. What makes the KPA sound so good is the 'all profiled together' bit which captures how all the parts interact, and I don't think total separation afterwards will be possible but as you say could perhaps be refined.


    However, I use almost exclusively DI profiles, and on checking them the cab portion of the profile is indeed empty (makes absolutely no difference whether the cab is on or off). If I then add for example one of tills cabs, which as we know is only in the cab section of the profile, it actually changes the sound of the amp section as well. This is easily checked by loading a DI profile, switching the cab off (no difference because it is blank anyway) then loading in a different cab. Although the cab is switched off you can still hear the change in the amps sound.


    I have found that in most cases when I do attach a cab for for use (in a live context) to send to the foh the spillover of the cab section into the monitors sounds very good anyway and just sounds like the eq has been changed a little, so its no biggy for me, but as a cork sniffer myself I understand other peoples concerns. I usually find increasing the mids sorts the change in eq the cab spillover brings and this tends to help the cab sound anyway in the mix.


    If possible it would be great to make it an option to add a cab to a DI profile without it affecting the DI profile. In effect we could then run the DI profile to the monitor outs with the main outs only running the added cab.


    This may well be impossible though depending on how the profiles work.


    Another option as I see it would be the option of an IR block in one of the fx blocks after the amp section.
    Personally I don't like IRs, I much prefer profiled cabs but it may be an option that people like me who prefer the powermp/cab route on stage would use to send a good foh signal.

    Good points, you have a lot of experience with this stuff in recent months. What is your take with the Atomic FR and KPA, with cabs "ON"? I know you normally use the Atomic's power amp to drive a traditional cab, but I was wondering your thoughts on that pairing. I had an RCF 312A in for a few days and in the end, had to return it. It IS a nice powered main/monitor for sure and the price is perfect, but my KPA patches at volume were still pretty lifeless and shrill :( I used a mixed of stuff I had tweaked in nearfields and some stock stuff and tried a little on the fly, it was close but no cigar for me.
    I'm the one testing out the EHX Magnum power amp into 1x12 and although that sounds still and a little lifeless as well, it's better and closer to my comfort zone.
    I have tried the Atomic FR in the past (with AxeFX I) and was let down a bit. Now maybe I'm thinking the KPA does the cab interaction thing better and might pair well with the Atomic FR? I could always test the way your are testing too, although I would never cart out that much stuff to a show. There is always the Atomic monoblock, but the fact it's also not rack mountable, another piece of gear and pretty expensive turns me too to that one.
    I went to a local shop at lunch today and played some real amps as a sanity check, the only one of any note was the AC15HW (older ones with Blue and ef86 channel which I dig). It sounded and felt good once the tubes got cooking, but I don't think it was MUCH better than what I'm getting from some KPA Profiles into my cheap SS power amp and cab. I need to upgrade my external stuff to the KPA, wish I had more gear cash :)

    Buried in one of the threads on these forums, Mr CK was talking about a potential update which involved creation of profiles with BOTH a mic'ed up signal as well as a DI to resolve the common complaint that profiles don't work so well with a real guitar cabinet. So there is hope on the horizon, though he did clarify that FRFR (a word that he "hates") will still be the optimal way to use your profiler.
    I think it will be very difficult to separate the amp head from the cabinet when making profiles. The reason why it sounds like the original amp is because you're recording the sound of the original cabinet. The profile is the whole of both the amp head and the cab.
    As such, expecting the Profiler to sound like just the amp head is unreasonable. It's like taking the original amp head and hooking it up to your cabinet and expecting it to sound like the profile. Not possible without tweaking.

    huh, i am really digging going to a tube power amp and my 4x12 with the cab sims off. sounds really good to me and my band mates love it too. everyone is different i guess.

    Quote from sleewell

    huh, i am really digging going to a tube power amp and my 4x12 with the cab sims off. sounds really good to me and my band mates love it too. everyone is different i guess.


    You are using a tube power amp. I use a Matrix and with this power amp some profiles are better than others but DI profiles (those that incluide the power amp) sound awesome compared with switching off the cab in the complete ones.

    Edited once, last by pacocito ().

    That's the best idea about the Kemper, i ever read!
    Especially for the Power-head/rack that would be soooo great.
    It would make the Kemper not only 100% but 150% perfect.


    This thread definitely needs a push!

    I've had a similar idea, while discussing with a friend about DI-profiles.
    If the "Return-Inputs" on the back are not linked together and can be used seperately,
    and the "Alternative Input" could be used for profiling aswell, you could get a 100% accurate profile of preamp, poweramp and cab:


    Signal 1: Amp Input, recorded via FX-Send into "Alternative Input"
    Signal 2: FX-Return, recorded via DI-Box into "Return-Input"
    Signal 3 = Signal 2: but recorded via Mic into XLR "Return-Input"



    The Kemper could then calculate the Cabinet (EQ-Curve) with the difference between the return-inputs.



    You might think, that the processor may be to weak for this new profile,
    but i think, that it's just the profiling process itself, that will require more computing capacity.
    This would result in a longer profiling process, but in the end that would be totally worth it! ;)



    Regards,
    Daniel

    I wouldn't use the FX Loop - you'll only get the preamp with that. Poweramp also has a huge impact on the sound. If Kemper will introduce this function then I'd highly recommend getting a DI Box you can put between the amp and the cab - they are like 15-20€ here in germany and well worth the money. I make all my DI profiles like that, they really sound very good!

    MJT Strats / PRS Guitars / Many DIY Guitars -- Kemper Profiler Rack / Kemper Remote / InEar

    Yeah you're right,
    but i compared a "send-profile" with a "di-profile" and it sounds nearly the same!
    Even the Di-Profile is a little bit 'better'...
    Maybe it doesn't mind the kemper (if the function will be integrated) if you use send or di, than everyone could decide it by his own :thumbup:

    Mh,... guess you tried it with a modern high gainer? The power amp doesn't have much influence then, I agree.
    But when you profile a JTM45 or JCM800 where much of the tone comes from overdriven PI or/and poweramp then a signal between the amp and cab is much better :)

    MJT Strats / PRS Guitars / Many DIY Guitars -- Kemper Profiler Rack / Kemper Remote / InEar