I was using a tone generator to check the functioning of some 3 way speakers and noticed the SPL output really dropped off above 13kHz. I wanted to quantify this so I measured the output with EASRA and a DBX measurement mic and the output did drop off somewhat above 13kHz, but only by about 3 -6 dB all the way to about 18kHz.
I then cranked up the mixer output a bit and listened right by the measurement mic. It appears it was my hearing that was dropping off. This was at about 95dB A fast in a basement shop, loud enough where the lower frequency tones were somewhat uncomfortable. So Fletcher-Munson nothwithstanding, I think about 13kHz is the upper limit of my hearing.
Well this is a little disheartening because sometimes I find myself twiddling EQ knobs in the 15kHz range and thinking I am hearing something. Like I am cutting some really high frequency hiss or, alternatively like I am adding "shimmer" or "sparkle". I think my brain might be playing tricks on me that I actually hear a difference. Or maybe the 16kHz EQ filter on the ASHLY MQX2310 has a wide overlap.
So my rather nebulous question is whether there are subtle nuances that you can you sense with respect to EQ changes at the higher frequencies or is it just my imagination?
The other question is how likely is it that the average audience member at rock sort of event would have good hearing at frequencies above 13kHz? I hate to think I was making big changes that everyone could hear but me.