[FireDragon76]

For years I have been trying to calibrate headphones or equalize them to sound relatively flat. Years ago I used a Radio Shack SPL meter and just placed it against the earpiece of a on-ear headphone, and that worked OK, though not great. Recently, I got the idea to try an in-ear microphone from Sound Professionals. Unfortunately, this method doesn't seem to work very well, as the microphone sits in the concha and not the actual ear canal, meaning the results have too much treble energy relative to the Harman target response (because the calibrations don't account for the decreased treble). I am not an audiologist, but I did try adding in some boost to account for the ear canal and eardrum resonances, but it added wierd colorations to the sound, meaning I don't think I got it quite right. Microphone placement seems to shift around the frequency response a great deal, and there's no easy way to correct for the microphone placement (to say nothing of the fact I have no clue how to calibrate the microphone to sound "flat", even forgetting compensations to try to make it fit the Harman curve).

So I got the idea to just take the in-ear microphones and put one microphone in a small stack of cotton rounds with a hole cut in the middle, and place the supra-aural headphone on top of that, with the cotton round being there to just provide some padding so the headphone doesn't press too hard into the microphone.. And this method seems to work best, especially calibrated to 1 db/octave slope, it produces results that are flat but tilted warm, similar to the Harman response curve. But I would like to upgrade my flat plate setup to something a bit better, without blowing too much money.