I’ve tried looking around for a simple tutorial on create IRs with Audacity and haven’t been able to find one.
What I want to achieve is mimicking a guitar pedal by creating an IR of it and importing it to another IR-supporting multi-FX pedal.
An “Impulse Response” is just a recording of an impulse sound + ambiance. They are usually recorded in 32-bit float format, though the actual format depends on the requirements of the program that you want to use the IR with. Common ways to create the “impulse” include: a hand clap, a balloon pop, a starting pistol.
The other common way to create an impulse response recording is to play white noise and then stop the noise “instantaneously”. Then delete the white noise up to the point where you stopped playing the noise - the remaining sound is the IR.
You’ll need to feed the impulse into the pedal. You can probably use a line-level (or headphone) output but you might need to turn down the volume. I assume you can find and download an impulse file (like a recording of a gunshot, or maybe something more ideal.)
Then you’ll need an interface with a guitar/instrument input to record the output from the pedal.
I’ve never done this, but I also assume there is something in the software to compensate for “imperfect” impulses. …A gunshot sounds different from a hand-clap and from what I understand a “true impulse” is theoretical and has infinite amplitude and a duration of zero. You CAN generate a digital/electrical impulse with a maximum amplitude (0dBFS) and a duration of one-sample but I don’t believe it has enough energy to make it useful.