Profiling amps & cabs separately vs. together. Darker tone?

    OK, this is what happens when I start pushing things. Once I figured out how to extract the cabs from profiled rigs into separate cabs and export those as tarball backups, I started thinking:


    A) "I wonder if the KPA's cab profiling results might be even better if performed separately from the amp."


    Likewise,


    B) "I wonder if the KPA's amp profiling results might be even better if performed separately from the cab."


    If either A or B were true, then that might be a case for profiling the two items separately and combining them later, saving the result out as a new rig. Hi fi! So, I tried this, a task made easier by the "Preamp Defeat" switch on my ENGL. I also created a "null cab" to play with by plugging a loopback cable between the send and return and profiling that. It worked, sounded fine.


    What I discovered though, was that the new rig I created, namely Profile(amp) + Profile(cab) was noticeably darker sounding than Profile(amp+cab). Hmm. Then, curious, I reloaded the (harsh and buzzy) no-cab amp profiled in Step B and then loaded the "null cab" into it expecting not to hear any difference. But there was - it still sounded harsh and buzzy, but some of the edge had gone.


    Has anyone else tried this? Should we always be profiling the amps and cabs simultaneously for best effect, or is there some subtle bug?


    -djh

    Simpler than that. My E570 is strictly a tube pre, no power amp. Likewise, my "cab" is just a Palmer ADIG-ST. Line level signals all around, Kemper -> ENGL -> Palmer -> Kemper. Both the ENGL and the Palmer have defeat knobs that allow you to take them out of the circuit, making it easy to profile them together or separately. In this experiment however I profiled the ENGL directly (Kemper -> Engl -> Kemper) just in order to be extra clean about it.


    -djh

    I assume that all this is just because it is not supposed to be used like that.....whatever you put in the loop will be seen and profiled as a full amp+cab rig...jumping the loop you've probably profiled the mic preamp of the Kemper.....

    "Music is enough for a lifetime, but a lifetime is not enough for music" Serghei Rachmaninoff


    Mmmm, a strange one. Really don't know about this at all.
    I know occasionally when I do a direct profile of my amps I get a really dark muffled profile. Then when I reprofile (as theres clearly something wrong when I hear this) the next profile will be fine. Maybe an intermittent bug. I think someone else experienced this too.

    That's why I performed two different experiments there, guitarnet70. One was to determine whether extracting the cab from a profiled cabless rig (thanks for documenting that technique, sheguitarplayer) was equivalent to profiling a bare wire (which is what every linear amp tries to be - a straight wire with gain.) We've also been encouraged elsewhere by Kemper to profile cabless amps, so in the absence of a manufacturer-provided "no cab" cab profile it seemed worth trying.


    Not to get sidetracked, but the point of even mentioning the loopback cab story was just to confirm my suspicion that something might be off, which I found curious. Additionally, when the cabless amp sounded brighter than the same cabless amp with the loopback cab, it was just grist for the mill. Or not, of course - I haven't done any more investigation since posting this. It may be nothing, so I'm just tossing it out there.


    -djh