To me the idea of taking an audio sample and using it to add space and character to a mix is a very cool concept. Obviously, I've used reverb and amp simulation plug-ins, there are a so many to choose from, but how do they work? I believe it might be possible to create impulse responses for reverb, cabinet modelling, and maybe even amp-modelling, so I'm setting off in search of answers...
heres what i know
I know that an impulse response is an audio clip that, when loaded through certain plugins in a process called "convolution" (yes really) are able to simulate either a room or a speaker.
It starts to get 'convoluted' here though, because when you capture your Impulse, you also capture the properties of each other thing you use to capture the sound. like the microphones you chose, their placement. your pre-amps and any other things that might colour your sound along your signal chain. I'm not too concerned about this part yet, first I have to figure out how to do it.
and what i don't know
So far i have more questions than answers, What kind of impulse do i send to the room or amp/cab? how long or short of pulse? a 30 second sine sweep? pink noise? Musical tones? Natural sounds?
Is it possible to model the sound of the amp? how is the process different than taking the sound of the room or the cabinet?
My guess is that 'it depends' and I'm not sure on what, so it's time to do some more digging.
As it turns out there are two methods to create impulse responses. the sine-sweep method is more accurate, but requires special tools to process the signal (a sine sweep) into an impulse. this is a technique I've yet to try for myself.
The Dirac pulse method, which is the one i chose to use. It's far less accurate but saves the extra step of having to convert the sweep into an impulse. Instead, routing the impulse directly through the source we want to emulate. In the video below it was a very nice fender twin positioned in a way that was sounding very nice! check out the video below to watch my first attempt at IR sampling
i don't **** know but lets make some
link below to download the test files
also check out the video
here are some resources for those who want to try this...
dirac pulse method (like the one used in this video)
sine sweep method (requires special tools)
tools for mac:
tools for windows:
tools for linux: akili (from repositories)