free impulses

Yes, but have you tried the Sony DRE777 impulses . Very pleasing indeed

my friend owns a building with a very large concrete & steel fire stair. the natural verb in there is absolutely luscious. i've been thinking about going in there with a mic to record it for use with SIR. so i have 3 questions: 1) what should i use to generate the noise? hand clap? snare hit? steel pipe? 2) how far off the transient should i trim the sample? 3) what's the best mic to use? here are the mics i have access to: SM57, SP C-1, AKG C3000b, Rode NTK, Oktava MK012. i imagine a condenser would be more suited, so that puts the SM57 out. and i was reading an interview with an acoustician in tape op recently about recording reverb in a reverb chamber and the guy said to use a small mic. thnaks...

Having absolutely no experience or knowledge to go on, I reply! I think you'd probably want to use a test tone. Or a variety of test tones. The reason I say this is that the clap/snare/whatever is invariably going to impart it's own charectaristics into the sound. A test tone would just give you the results of a clean sine wave. Mathematically, it'd be easier (and likely truer) to shape one convoluted wave (your carrier) with a sine wave (or derivative) than with another convoluted wave (a clap). That said, I'm just talking out my posterior, Feel free to correct me if you have actual knowledge. Really I'm just padding my post count here. I'm coming for you! -Olaf