Amp & Cab Morphing Without the Impossible CPU Hit

  • We know the CPU can't render two Profiles at once. We know Profiles are only a few kb in size.


    Bearing these facts in mind, shouldn't it be possible to load two Profiles into the edit buffer and render a single resultant amp / cab or both based upon an interpolation of the raw (Profiled) data of each? IOW, you choose how much of each DI, Merged or Studio Rig you'd like to hear via a "blend" parameter, and this resultant set of parameters, which would be no different in size or scope than that of a single Rig, could be rendered through the Profile-playback engine... in realtime.


    Further possibilities employing the same principle spring to mind:


    Blending Cabs.
    Awesome possibilities of morph-pedal assignment. The mind boggles!
    Splitting the single blend parameter up into hitherto-unheard-of parameter sets that allow different characteristics of two amps or Cabs to be blended.
    [Insert plethora of imagined possibilities here]


    To recap:
    Profiles are small files that contain a specific set of parameter values determined during the Profiling process.
    I propose that the KPA should in theory be able to be programmed to allow morphing / blending between any two of these sets because it doesn't have to involve rendering two Profiles at once - just a basic, low-CPU-overhead, user-determined blend / interpolation / morph of the raw data that differentiates one Profile from another, just as morphing between two parameter sets within a single effect doesn't require two instances be calculated at the same time. The resultant data values could then be treated as if they represented a "regular" Profile.


    In theory. Unless the K-Team™ has a spanner to throw in the works...

  • This would be great. I would find it really useful to be able to morph from a rythm profile to a higher gain lead profile. At the moment I add a morphed boost to achieve this from one profile. That works quite well, but it would be nice to have the option to morph to a different profile.

  • Indeed, djdyer!


    Also, the possibilities when blending two amps and / or cabs would be literally-endless.


    No other "modeller" provides this option AFAIK, so there's that too...


    It will happen.

    Oh, how I wish I could be as-confident as you, mate!

  • Thank you, AJ.


    I must be missing something 'cause I understood your description as meaning that at some point during the pedal's travel one Rig would "instantly" change to another one.

    It's as you described, Nicky, though we'll have to settle for the regular speed of changing a rig as "instantaneous" in this case, Nicky.


    It's quite simple. Programme the expression pedal to send a PC# when it crosses a CC# of say 64. And then, when the CC# is less than 63, it should be on the regular profile for that patch.


    Seems like a crazy leap, but it's quite easy, Nicky. Kemper Amps could implement something similar, methinks, I'm just using a programmable midi controller.


    Logical programming is key. If, then, else.

  • Well, I was right then; it is instantaneous, for all intents and purposes. I have my unit set to crossfade, I think (haven't looked at this since day one when I set the parameter) at 10ms. That, which I think is the longest crossfade the unit offers, is to the human ear instantaneous.


    What I'm talking about in the OP is the KPA's giving the impression that it's morphing between 2 amps, amps & cabs, or cabs at any rate you like, controllable with a pedal or simply set as a blend and left there.


    Please re-read my proposal if you're not clear on it, matey. I thought the forum would be falling over itself over this, figuring it'd be a way to, as the title suggests, get around the limitation of the now-impossible CPU hit that'd otherwise be incurred if two Rigs were rendered at once in order to make blending and morphing possible.

  • I love the idea Nicky, brilliant! Should be theoretically doable, especially as you say with such small kb of data per rig. I hope somebody at HQ is looking into this possibility.

    Gary ô¿ô

  • I think the small KB of the profile size isn't indicative of the DSP required for processing


    My guess is that it's similar to MIDI instructions. A midi file is so small because it's is a set of instruction that trigger a DSP powered player (synth or software instrument). Now the audio player system in the Kemper under the hood definitely requires significant horse power. and again my guess is that the small Profile KB is not involved in any of the heavy lifting but merely giving instructions similar to what midi file does while all the main sound processing come from the sound engine.

  • Of course it's not-indicative; that's exactly what I've assumed, Dean, and it's central to the idea's being "viable", at least in theory from our non-insiders' perspective.


    To use your analogy:


    The mix-blend and / or morphing parameter/s would essentially be adding / subtracting one set of MIDI values from the other before they're processed by the synth or software instrument.


    IOW, no more overhead than a basic real-time calculator = pretty-much zero for a modern processor.

  • That's a very slick way of looking at it but as you said from the non-insiders prospective. It's basically expected to calculate the resultant mixed sound without actually calculating the actual ingredients except in the two further positions of the blend. I have no idea if this would be easy or extremely complex, but it's certainly outside the box brilliant approach and I hope it could work.

  • I've not seen this parameter-premixing idea mentioned before, Lokasenna.


    Sure, we've had multiple requests for simultaneous Profiles, which logically would allow one to "blend" the mix between them, but we all now know that two cannot be rendered at once by the CPU.


    It's basically expected to calculate the resultant mixed sound without actually calculating the actual ingredients except in the two further positions of the blend.

    Close, but not-quite, Deano. No need to calculate two positions.


    Let's take, for example, Parameter 01 from each Profile:
    It would be "blended" mathematically first, producing a single parameter which is treated as if it was only ever the only Parameter 01. If Parameter 01 in Profile A is 1, and it's 10 in Profile B, the blend range would be from 1 to 10, representing 100% A, 0% B through to 0% A, 100% B.


    We know that Rigs can be switched in a matter of milliseconds, so the realtime feasibility of morphing or manual blending via a percentage knob of the two Profiles should theoretically be "instantaneous"... and gratifying, even if each parameter update requires the entire Profile be recalculated.


    If indeed "stuttering" can't be avoided when morphing, even through buffering, at the very least, dialling in a static-mix blend should be possible in this case... in theory...