Can't get my profiles close enough

    Quote from tgs

    The point with my further investigation is to find what is the problem and to find a remedy. Hopefully one that can be implemented already in the Kemper, when profiling. I sincerely hope that my posts are of use and interest to some. If you're happy with what the Kemper does for you, then great! I'm also VERY happy with my Kemper, BUT I'm experiencing a problem, and with my tests I'm coming closer to a conclusion that the problem persists regardless of signal chain. I'm hoping that someone can either confirm this or get a different result. It's not that it sounds like crap. I'm just hoping for an improvement.

    TGS i'd like to say thankyou for your time and efforts with your findings and graphs. i'm certainly no engineer or techie, but i do find this thread fascinating. if there was a slight eq curve that got it even closer to the real amp (wow! 8o ), that would only be a bonus to kemper users, if they had a preference between.

    We will investigate this.
    We have done intensive tests prior to the release of the profiler and we haven't changed the profiling algorithm since then.
    We are aware that some profiles need refining in the bass areas, but so far we have not identified a bias in the direction you experience.


    Please send one of the profiles in question to our support. It will be interesting to see if your profiles show aspects that are not captured by the profiling process, and are reluctant to refinement.


    Checking this will take some time, as I will go for summer holidays this weekend (two weeks).


    Thanks
    CK

    Quote from MadH

    Are you recording both clips (reference AMP and profile) through the Kemper?


    Yes. And as explained earlier, I also tried recording a parallel signal from the mic preamp directly and the result was the same. I've also tried both with an external preamp and with the mic straight into the Kemper. Same result.


    Thank you CK! I'll make a couple of profiles soon and send them to you. If there's anything more I can do to help in the process, don't hesitate to ask.

    I've found the same sometimes with the profiles I have done. Most of the time needed refining in the bass area. Also very similar results with the curve.....perfect just except for the low area (very rarely the high end)


    I've either done the following
    1.added some bass or the studio eq then compared curves
    2.not worried about it!!!! at the end of the day every recording I always cut around 100hz for the mix so in a way its actually helping me ;)

    If you could post a couple of the Dual Terror profiles at different gain stages it would be greatly appreciated. I would check against some other Orange amps I have......or email me via pm.

    "More Guitar in the Monitors" :thumbup:

    Quote from bshaw92

    If you could post a couple of the Dual Terror profiles at different gain stages it would be greatly appreciated. I would check against some other Orange amps I have......or email me via pm.

    I can do that when I have a moment. BUT, the frequency discrepancy is exactly the same with my JCM800, Mesa Trem-o-Verb and 5150, with two different cabs and different mics. I've also tried two different guitars, external preamp vs Kemper's onboard preamp, etc etc. So the issue is not specific for the Orange.

    Yeah I understood your study and findings. I just have Orange amps and do not have the others so I was going to use yours and some of mine and then compare. Whenever you can....

    "More Guitar in the Monitors" :thumbup:

    My profiles usually have very little bass, but then so does my amp. The profiles seem to sound even thinner than the amp though, while some user and commercial profiles sound extremely bass heavy (Armin's JVM410 is one of them) to the point of being practically unusable, at least through my Yamaha DXR10 on a pole mount with all DSP switches set to off.


    After reading your posts I tried adding a studio eq in the X slot with the following settings:


    Bass freq: 120Hz
    Bass level: -12 dB
    Mid freq: 110Hz
    Mid Q: 0.78
    Mid level: +2.5 dB


    The remaining parameters remained unused. I've set the bass frequency a little higher than you did because the bass shelf filter slope in the KPA seems softer than the one you used (24dB/oct IIRC, maybe the Kemper studio eq has 12dB/oct).


    The result was that those bass heavy profiles sounded *much* better. Can you confirm if doing this on the Kemper side will bring those curves closer together?

    Quote from Deny

    The remaining parameters remained unused. I've set the bass frequency a little higher than you did because the bass shelf filter slope in the KPA seems softer than the one you used (24dB/oct IIRC, maybe the Kemper studio eq has 12dB/oct).

    No I used a high-pass filter. The low band EQ on the Kemper is shelving.

    Quote from Deny

    The result was that those bass heavy profiles sounded *much* better. Can you confirm if doing this on the Kemper side will bring those curves closer together?

    Try to find a way to measure it and compare. Could be a quick work-around for the moment, until the issue is (hopefully) addressed.

    I've tried finding an analyzer online and the three I've installed don't provide an option to save a snapshot for comparison. Does anyone have experience with a specific "free" program that will accomplish this task so I don't have to keep searching? I've been able to use the software and an app on my phone, but for accurate numeric comparisons sake I need the snapshot. I compared via recording using ABY switch. To get closer profile results I had to change the amp settings a bit (clarity, bias..etc). Setting my Orange aI mp eq. neutral (12:00) I adjusted the bass to 1.4 and mid to about the same on the profile. I refined about 5 minutes doing multiple activities. With my profiles I find a little of the tube amp "growl" missing as well so I starting playing with everything to see what it would changed. I went to the cabinet adjustments and found changing the "character" added some of that "growl" back in as well as some amp settings mentioned earlier. So I have added bass, mid and set the character on the cabinet to -4.5. That along with the amp settings sounded as if it got much much closer. To have a scientific result I would need to run through an analyzer that could compare the two output results as you have done. The gain on my Orange was at 3:00 with the volume at about 8:00-9:00. I cannot give more information until I can check against each other....

    "More Guitar in the Monitors" :thumbup:

    Quote from bshaw92

    I've tried finding an analyzer online and the three I've installed don't provide an option to save a snapshot for comparison. Does anyone have experience with a specific "free" program that will accomplish this task so I don't have to keep searching? I've been able to use the software and an app on my phone, but for accurate numeric comparisons sake I need the snapshot. I compared via recording using ABY switch. To get closer profile results I had to change the amp settings a bit (clarity, bias..etc). Setting my Orange aI mp eq. neutral (12:00) I adjusted the bass to 1.4 and mid to about the same on the profile. I refined about 5 minutes doing multiple activities. With my profiles I find a little of the tube amp "growl" missing as well so I starting playing with everything to see what it would changed. I went to the cabinet adjustments and found changing the "character" added some of that "growl" back in as well as some amp settings mentioned earlier. So I have added bass, mid and set the character on the cabinet to -4.5. That along with the amp settings sounded as if it got much much closer. To have a scientific result I would need to run through an analyzer that could compare the two output results as you have done. The gain on my Orange was at 3:00 with the volume at about 8:00-9:00. I cannot give more information until I can check against each other....

    Are you playing while comparing or are you using a pre-recorded DI signal? It's more accurate with the latter since you're comparing the very same thing. Anyway, if you can make wav files of the two, I can run them through Ozone for you and capture the curves.


    Regarding the ABY pedal, that's one way to do it. Another easy way (which is what I tried apart from a couple of tests just to rule out that this method was degrading the audio somehow) is to stay in Profiling mode and switch between "Kemper Profiler" and "Reference Amp". This is how I ran most of the tests.

    Maybe you could try this in demo mode:


    http://www.bluecataudio.com/Products/Product_FreqAnalystPro/


    "Demo Limitations


    One single instance of the plug-in per session.
    The plug-in is frozen for 4 seconds every 40 seconds."


    So it might work.


    EDIT: Seems like the Ozone demo should work as well: "In Trial mode, Ozone 5 and Ozone 5 Advanced (including Insight) will
    work without restriction for 10 days. After 10 days, the product will
    operate in Demo Mode, and will insert silence at regular intervals"

    Edited once, last by tgs ().

    Quote from tgs

    No I used a high-pass filter. The low band EQ on the Kemper is shelving.

    Try to find a way to measure it and compare. Could be a quick work-around for the moment, until the issue is (hopefully) addressed.

    Unfortunately there's only one "X" slot after the amp block, so if I put a low pass filter there I won't be able to add the +2.5 dB @ 110 Hz. I do own a pink noise generator and could take some measurements but it would take lots of time, which I'm a bit short on right now. I'll keep trying to match the low end on my own profiles by ear and see what I can come up with.

    Quote from Deny

    Unfortunately there's only one "X" slot after the amp block, so if I put a low pass filter there I won't be able to add the +2.5 dB @ 110 Hz. I do own a pink noise generator and could take some measurements but it would take lots of time, which I'm a bit short on right now. I'll keep trying to match the low end on my own profiles by ear and see what I can come up with.


    Quote from Deny

    Unfortunately there's only one "X" slot after the amp block, so if I put a low pass filter there I won't be able to add the +2.5 dB @ 110 Hz. I do own a pink noise generator and could take some measurements but it would take lots of time, which I'm a bit short on right now. I'll keep trying to match the low end on my own profiles by ear and see what I can come up with.


    You can put an EQ in the Mod slot as well.

    Quote from tgs


    You can put an EQ in the Mod slot as well.

    Right you are, however I couldn't make it sound right with two filters in series. Then I remembered that the peak parameter in the LPF and HPF filters produces exactly what we're looking for, doesn't it? A resonance bump right at the cut frequency. Too bad the parameters in the HPF wah aren't in Hz and dB, anyway here's what sounded best so far through trial and error:


    Wah High Pass ("X" slot)
    Manual: 1.8
    Peak: 0.3
    Pedal Range: <0%>
    Peak Range: <0%>
    Pedal Mode: On
    Stereo: <0%>
    Mix: 100%
    Duck: <0.0>
    Volume: -4.5 (for some reason this effect is very loud at 0.0)


    It would be great if someone could confirm that these settings compensate for the bass response deviation in the KPA.

    bshaw92, you could use Audacity for plotting the spectrum. Audacity is free software (GPL) and available for Windows, Mac OS X, and Linux.


    Usage:

    • Open your audio file, select menu "Analyze" - "Plot Spectrum..."
    • adjust parameters to taste
    • save spectrum data with "Export..."
    Quote from trebie

    bshaw92, you could use Audacity for plotting the spectrum. Audacity is free software (GPL) and available for Windows, Mac OS X, and Linux.


    Usage:

    • Open your audio file, select menu "Analyze" - "Plot Spectrum..."
    • adjust parameters to taste
    • save spectrum data with "Export..."

    Does it have the possibility to show multiple plots at the same time though? That's the thing I like about Ozone, it makes it very easy to compare plots.

    Quote from Deny

    It would be great if someone could confirm that these settings compensate for the bass response deviation in the KPA.

    I'll try with these settings tomorrow and post my results. It could be a handy quick fix until the issue is hopefully fixed. Too bad there are not more slots available in post. Would be great (albeit confusing for some users) if all fx slots could be selected as pre or post. Maybe as a hidden feature or something.