Ok guys, it seems pretty simple... it took me a few minutes to understand it, and I've tested the method "impulsing" an amplitube 2 cab... it works!
So just download Voxengo Deconvolver:http://www.voxengo.com/product/deconvolver/
The demo version works perfectly for what we have to do, so you don't need to have a registered version (but the demo will allow you to create 3 impulses per session, so, after 3 impulses, you have to restart the program
Open Voxengo Deconvolver.
We need a "TEST TONE", basically a sine sweep containing al the frequencies we can hear... just click on "Test Tone Gen", use the default settings (24bit, 44100Hz (or superior, best is 96000Hz), mono,12 sec., DON'T CHECK "apply fade in-out for reverse" ) and click on "generate".Create an impulse response from a real gear
Ok, now we need to route that wave file inside the Cab/Mic we want to capture... so you have to route the file inside the power amp of your head (fx-return or power-amp in) and record the cab output with the mic...
Just connect your soundcard output to the poweramp and record the mic signal (you could need 2 pc or a soundcard that allows you to play and record at the same time... you could do that with a DAW). Beware the clipping of the Test Tone!!! It doesn't have to clip!!! Lower the volume!!!Create an impulse response from a software sim
It's more or less the same thing, just easier!
We need to open our DAW and create a mono track, then load the Test Tone on it.
Now we have to open the VST from which we want to take the impulse response in the track insert, for example GR.
Now we have to close or bypass all the components we don't need (stomps, amps...) and activate only the cab+mic section.
Play the Tone Test now to see if it clips inside our VST. If so, lower the volume or use the "learn" function!
What we hear when we click "play" is just the Tone Test processed by the VST, and this is what we need, so export the file into a .wav file!For both, then...
Obviously, if you have created a 96KHz test tone, you have to record at the same sample-rate!!!
Export the recorded tone on a 24bit Wave Mono file.
IMPORTANT: when you export, remember to add a bit of silence at the end of the clip you're about to export
The recorded tone will be the "file to process" in Voxengo (obviously the Test Tone File is the Test Tone we have generated a while ago, so the original 12 s sinesweep).
Set "Out Bit Depth" to 24 and select just "Normalize to -0.3dbFS".
You could also check the "MP Transform" option (the manual says that gives more realistic results)
Click process and you'll have a wave file in the same directory of the processed tone.
This is your impulse!
(probably you'll have to tweak the volumes to get the impulse right... so, try, try, try!)
Hope it helps!
For any question, just ask, I'll try to help you!