Step 3 - Choose where to save, enter file name, hit Enter. Step 2 - Export measurement as impulse response (literally: File > Export > Impulse Response as WAV) The more sophisticated method is specific tools that emit a calibrated sweep tone and capture the result, then use special processing to convert the captured audio into an impulse response.You make this sound complicated, but I could get it done in under two minutes with REW, which happens to be freely available online. Generally now I just use the IRs and inbuilt cab emulations in all the plugins I've collected and they have done a better job of IR capture and processing than I can. A number of convolution processing VSTs have them inbuilt too. There are a heap of tools around that do this signal generation and processing. Guitar cabs were a bit meh and I didn't like the results on bass cabs at all - all the mojo went away. This is less fussy than the pulse method but some things don't seem to work that well, like I had good results capturing reverbs this way. The more sophisticated method is specific tools that emit a calibrated sweep tone and capture the result, then use special processing to convert the captured audio into an impulse response. I have played with this and had to do a bit of messing around with the result in Audacity to clean it up and get something usable - and even then it often doesn't sound that much like the real cab (but it can nevertheless be interesting and useful). but it can be a bit crap in practice and hard to get decent results from. This 'ghetto' method is simple and the resulting WAV file can often be loaded directly into convolution plugins without much further processing. And choose the cleanest and most accurate amplifier you can (ie not a guitar amp!). So choose a mic and position that you would actually use for a guitar cab. There is a big catch here in that you are capturing the character of the amplifier and the mic along with the mic's position. The ghetto method is to send a very short sharp impulse - a click (essentially a very short square wave) - to the cab or into a space and then capture the 'impulse response' via a mic.