Originally Posted by mdme_sadie
Not the same thing. What you are thinking of is called Match EQ, and standard impulse response technique, the Kemper does indeed send an impulse and measure the response but matching the frequency range is only one part of what's going on for the Kemper. The distortion character, quantity, response curves and about 60 other parameters are all set at the same time through the profiling process. Simply put it's an amp sim that sets it's parameters via profiling. You'll also be waiting a long time for a plugin, Christoph is agressively protecting his IP of the Kemper and it's approach/algorithm with a patent (you can view the submission online to see how the Kemper works).
I'm cautiously optimistic on this. I read the manual and my cynical self says that this is smoke and mirrors to a degree.
Let me give my take on what it appears to be. He wrote an amp simulation with many different parameters. Instead of packaging these into discrete models like everyone else does (Dumble Cone, Recto Clone, Diezel clone, Fender Twin
Clone, Matchless clone, etc.) that were programmed at the factory, the profiling program listens to the content and makes decisions based on what it hears.
The program analyzes the distortion and is able to tell (perhaps) how many gain stages (fender or marshall circuit), what kind of clipping, the decay characteristics, feedback, etc. It might be able to glean some information on the pick attack, etc. It probably also has several different speaker parameters that can be set. Based on what it hears, it sets the parameters of the simulation and it labels it based on the type of amp.
Probably the biggest part of the profile is the autoEQ, which encompases the amps EQ stage, the mics, and the mic technique.
So what you end up with is an amp simulation with some set of unknown parameters that are set by by a program that listens to the amp. It encompasses the cabinet, the amps tone controls, and the mics / miking technique to create a "snapshot". **Unfortunately, it also encompasses the guitar and guitar pickup. (based on the playing demo portion of the profile.)**
I think you can anticipate my scepticism..
The amp is only profiled with a single listening with controls and mic set a particular way. What happens when you lower the gain? Or the EQ? More importantly, what happens when you change guitars???
My guess is that the amp simulation is programmed with a gain sweep and EQ controls at set frequencies. So unless the amp (say) has passive tone controls and gain sweep that functions very similar to the simulator, when you deviate from the "snapshot", the tone will start to sound very different.
And of course, when you change guitars and pickups, how much of the guitar played into the profile?
Then, what would happen if you attempt to use a pre-amp effect, like a wah, a compressor, or the myriad of boost pedals? Will the simulation behave the same as the real amp? My guess is NO, it will not. When you switch guitars, will it sound the same? My guess is NO, it will not. You are basically left with the performance of the underlying dsp simulator.
Philosophically, is it better to have a snapshot/profile that sounds correct only when it is played at baseline settings, or is it better to have amp models that were custom programmed (Line6, axefx, eleven rack, revalver, etc..) to behave like the real amp.
A programmed amp sim will more likely have the tone pot frequencies correct, where the profiled one will not. They may also be able to add custom logic to the programmed sim to encompass unique behaviors that are not seen while profiling.
I don't doubt that there is a WOW effect when the amp is first profiled. When you profile your own amp, and then play back the profile with your own guitar, through the original speaker cab, it will probably sound very close, and be a WOW moment. But for guys who dont have the original guitar/cab, or if you start to tweak the controls, it will start to fall apart.
Perhaps you can understand my scepticism. I am sure the profiler can get a close snapshot, but I doubt there is any way for it to behave properly to pedals, tone/gain changes, or guitar changes.