jaakkopasanen
100+ Head-Fier
manufacturer information, people with the same mic and a good experience of it, or yourself after you go and measure a bunch of sound sources at various levels and find out some pattern in the distortions that correlate well with levels at certain frequencies.
but I don't want to worry you for nothing, using speakers at a distance in fairly realistic conditions, you probably don't get all that loud and most mics should handle that just fine as they were made for such conditions. I was just bringing it up to make clear that while SNR is an obvious concern for us all, the ideal measurement conditions are probably not going to be when we manage to push the speakers to 1337dB ^_^. be it for the mics or for the speakers.
My idea here would be not only to have this working for myself but also create a process, a guide and tools so that pretty much anybody can do it themselves. In that sense it's not realistic to ask the random headphone enthusiast to know or to learn how to detect distortion in the impulse responses or even to go read through manufacturer documents. What I really would like to have is a almost one click solution which processes the sine sweeps, analyzes them, gives warnings to user if things didn't go as expected and of course produces the output impulse responses which can be directly used with different convolution softwares. Something like what I did with my AutoEQ project. Of course the user still needs to own the mics at minimum so it's not quite possible to have that low level of commitment from the user.