Който знае English да чете. Ако има някой да го преведе за другите още по добре за тях.
What is an impulse response?
For the guys that don't give a fuck about explanations: what is an impulse response? A .wav file. This is all you need to know.
For the others: what is an impulse response?
An impulse response is the output of a system when the input is a Dirac impulse (for digital stuff). The Dirac impulse doesn't really exist, cause is teorically a signal with amplitude 1 and length 0 (that's why it doesn't exist).
So if you run a Dirac impulse in the input of your system, you'll get the impulse response on the output.
The impulse response contains the linear characteristics of your system (i.e. frequency response) and does not capture non-linear things (i.e. distortion/saturation).
This is just a rough/stupid/useless-for-musicians description, for more informations you can search on the net...
Basically impulse responses can be used to capture frequency response and reverb.
The cab impulses you'll find here are just impulse responses of cab + mic systems (remember also the they contains also the frequency response of the power amp and the mic preamp).
Impulse responses are REALLY accurate. An analog cab sim (like ADA, Palmer, etc.) will NEVER match the accuracy of an impulse response. In this case the digital world fucks the analog world right in the ass. Believe it or not.
POD, V-AMP, Amplitube 2 and Guitar Rig 2/3 cab sims are ALL impulse based. The problem is that the impulse responses used are a bit crappy, that's why I (and a lot of guys here) never use them...
Ok, how to use them?
First of all, the only amp sim that actually supports external impulses is Revalver MKII.
So, if you want to use impulses on a standalone application, the only way is to use Revalver MKII.
Just load the RIR Module (under the cabinet section), click on "load" and then select the impulse response you want to use.
For the other amp sims, you'll need a DAW (Cubase, Reaper, Sonar, etc...).
Load your ampsim and BYPASS THE CAB (this is IMPORTANT).
How to bypass the cab?
Guitar Rig: just CLOSE the cab (or matched cab) module. I mean CLOSE, not switch off! This is IMPORTANT. GR cab-sims even if switched off, do change the eq! So, you HAVE TO CLOSE IT WITH THE "X" BUTTON.
Amplitube 2: go into the cab section and activate the BYPASS switch you see in the upper right corner.
Wagner Sharp: you don't need to do anything. Wagner doesn't have a cab emulation.
Dirthead 0.6/0.8: switch off the "CABINET" button on the right of the interface.
BTE Juicy77: select "cabinet disengage" or something like that in the lower bar of the interface.
Simulanalog JCM900: you CAN'T bypass the cab... I know, that's bad...
Now, if you have bypassed the cab correctly, when you play a distorted preset you'll hear a total shitty sound, fizzy as hell, no bass, harsh... it's ok, you're hearing how an amp sounds like without a cab.
Now, after the amp-sim, you have to load a VST that allows you to import impulse responses for convolution.
I'll describe only 2 programs: Voxengo Boogex and KeFIR, cause they're FREE and with NO LATENCY.
Voxengo Boogex
Get it here: http://www.voxengo.com/product/boogex/
Boogex is an amp-sim, if you want to use it ONLY for cab simulation, you have to set all the parameters FLAT, or it will change your eq/sound.
So, open it and set, from the left: Lows Mids and Highs to 0db, Tone to 0%, Drive to 0db, Dynamics to 0%, Phase to 0%, Out as you want (it's the volume control), Dry Pre Cab and Dry Post Cab to "-inf" (knob all the way down).
The "Speaker Cabinet Impulse Response" button MUST be ON, obviously.
Then click on "file" and select your impulse (a .wav file).
An important thing about Boogex: this software features a built in LPF and HPF. They can't be totally bypassed. The best thing to do is to open them to the max. How? Click on the green point in the right area of the graphic section of the interface and move it all the way to the right, then click on the white point in the left area and move it all the way to the left. This will "open" the filters.
KeFIR
Get it here: http://habib.webhost.pl/vst_keFIR.php
KeFIR is a simple VST that allows your to load impulse responses.
Just click on "Load", select you impulse response (a .wav file) then set the "Mix" parameter to 100% (this is important) and set the length as you want (more length = more cpu consumption). Don't set it too short or you'll end up bypassing the impulse. Most impulse responses (like the GuitarHack's ones) have the tail cutted, so set the length to the max is useless. Just leave it as is when you load the impulse.
Set the "Gain" knob as you want.
Play... if you hear a normal tone, with no harshness/fizzyness, you're done.
I have issues with Boogex sometimes... I load it and I have no sound out of it... I don't know why... to solve the problem remove the track where you've loaded Boogex, create another track and reload it. Works for me.
Remember that you can use impulses with real preamps/pedals too.
Just connect the preamp/pedal output into your soundcard, load one of the programs above, load an impulse and play.
WARNING: DO NOT CONNECT THE POWER AMP OUTPUT OF YOUR HEAD TO YOUR SOUNDCARD! USE THE PREAMP OUTPUT ONLY, OR THE FX-SEND. IF YOU HAVE A TUBE POWER AMP, YOU HAVE TO CONNECT IT TO THE CABINET ANYWAY, OR YOU'LL DAMAGE THE TUBES AND THE TRANSFORMER ($$$).
