Share your experience of matching the profile to the reference

    Hi


    I've recently bought a Kemper and have been very impressed with what it can do. Sometimes it's frighteningly accurate, but I've come across a few slight anomalies in the profiling process and I wondered if some of you guys could share your experiences of optimising this:


    1. The profile is usually seems to have a slightly different frequency response to the source. It sounds like it's a down a little bit in the low end, around 100 Hz or so, and up in mids at around 2 kHz. It might be that it's just not compressing in quite the same way, and so the high mids jumps out a little bit more than the reference amp tends to when you hit hard. I've done a minute or so of hard hit chords after each automatic profile. Is that enough? Is that refining stuff comparing the profile to the reference and refining the response? Should I do this much more? Any tweaks to the tone stack or amp section settings seem to take me further away from what I expect, much as they do offer some very cool ways to create new sounds from an amp.


    2. The high gain sounds seem ok, but the cleaner the sound, the less natural the dynamics seem to get. I find that the cleanest sounds seem overly dynamic, almost disappearing at times and then coming in really strong if you harder, with what almost sounds like a low end thump on harder picked notes. Is this something to do with distortion in the chain? Typically when mic'ing an amp I'll be using a number of phase aligned mics, some of which will certainly distort more than others. For this first profiling run was a mixture of ribbons, dynamics and valve condensors into 1073's, and then summed on an old EMI TG desk. Obviously a lot of those things distort. Is this throwing the process off? I'm not against using single mics, its just not how I would normally work with many of the sounds I'm profiling. This effect seemed to creep in on my old Super Reverb, which is quite a 'compressed' sort of sound, even when at very low gain. That didn't quite translate the way I expected it to.


    SO...Have you guys come across any of this stuff and have you discovered any tricks that might be useful? I'm keen to hear about other people's experiences.


    Overall I'm really stoked with the thing. It's quite a step forward.


    Thanks for any advice.


    Jack


    PS...does anyone have exact figures for latency both using analogue IO and SPDIF? Or does it depend on the profile in addition to the processing, ie how far the mics were originally? It doesn't really matter...I can just measure and nudge as required. It's just for aligning things that are multed through the unit.

    If I were you, I'd probably email Andy from the amp factory, or armin from soundside profiles. You obviously use some high end gear, and these guys use very much some of the same equipment and probably have more experience than just about anyone here profiling amps :) they are also extremely helpful, I'm sure either would help you here as well publicly, however they may not see your post. The results of the Kemper and the extreme praise of the unit as a whole is very tough to argue against in my opinion, if I had to guess to it probably has more to do with your outboard gear than the Kemper itself, however I am definitely not qualified to answer such a question.

    Quote

    The profile is usually seems to have a slightly different frequency response to the source. It sounds like it's a down a little bit in the low end, around 100 Hz or so, and up in mids at around 2 kHz.

    +1!
    + more compressed sound profile + "digital" nature of the upper band :cursing:


    [Blocked Image: http://www.brickwall.pl/gify/i…w-what-i-mean-420x250.png]





    These differences hard to pick up on the monitors, but on good headphones (I am using DT770 Pro) - no problem;)
    Anyway, on a raw track the difference is at the level of 10%, in the mix? I do not know if anyone will recognize the differences.


    KEMPER PROFILE vs Real 5150
    https://soundcloud.com/sinmixb…mper-5150-2-real-5150-mxr

    Laney IronHeart Real amp vs Kemper Profile
    https://soundcloud.com/sinmixb…/laney-ironheart-real-amp


    Stay metal! :thumbup:

    My advise is to prevent clipping, poweramp distortion, compression and also any kind of saturation to get the best profiling results. Whenever my profiling results were really off that you could hear a siginificant difference it seems that one of the components within the signal chain did not have enough headroom.


    - Don´t crank your amp. Even if you have an old Marshall without master volume, it will sound better if you prevent power amp distortion and add the missing gain afterwards.
    - Don´t overload your speakers. This probably won´t be a problem with a 300 Watt Marshall cab, but if you have a 1x12 cab with a vintage speaker, make sure you have enough headroom for the ultra low KPA test signals.
    - Don´t overload your mics, make sure you also enough headroom here. Should not be problem if you follow the rules above.
    - If you are using outboard gear like a submixer or external EQ, be extra careful here. Set the input gain to the correct levels, and then backup the input gain for some extra headroom. Also don´t clip the output here.
    - Adjust the return level of the KPA. Even if the KPA automatically adjusts the return level i would pay attention to this and even set the return level a little lower so that the Profiling input signal is lower than your reference rig. The profiler will increase the volume of the profile automatically.
    - For the beginner, don´t use outboard gear like compressors or tube preamps which add compression or saturation even if they are expensive. If don´t know exactly what your doing, this might have some negative impact on the dynamics.

    Thanks very much for the input. I'll experiment some more. It could be that the chain is too coloured but to be fair the marketing blurb states that it's all about capturing the recording chain as well as the amp. My gain structure was conservative but that desk has a lot of harmonic distortion. I'm not sure how to avoid power amp distortion in all these vintage amps. It's pretty much what they do. Anyway thanks for the advice.


    Jack