The difference is these “other stimuli” are, unlike headphones, basically always going through normal, location-laden HRTF processing by the brain, whereas the processing committed to the perceptual “chain” with headphones (for lack of a better term) is diffuse; if diffuse stimuli like headphones commits any dips, it would be accounted for in the diffuse field head measurement provided it is adequately bereft of frequency response coloration arising from specific source incidence. In other words, dips are common features of HRTFs, especially ones based on single sound source locations at specific azimuths and elevations, but diffuse HRTFs tend to be a bit less prone to large dips in this area, and since we’ve eliminated the HRTF, we can conclude the dip is not a feature of my HRTF or my hearing, but of the interaction between headphone and ear—whether that be due to ear geometry/input directivity, driver positioning, acoustic impedance, or some mix thereof, your guess is as good as mine.
Not a normal feature of my hearing, but a normal feature of the system comprised of my ear + headphones when coupled to my ear via a small, pressurised spring of air. I appreciate the concern for my hearing, but I think its simple physics that if there’s a lack of magnitude, there’s a lack of sound pressure, thus I am not committing any damage to my ears by filling in a dip hahah
What do ya mean by this? Like, small positioning differences between when I got the DF measured vs. when I use the mics at home?
Would be interesting, but again the issue is that with the speaker measurement, if I’m listening to the speakers, my brain is subtracting all of the idiosyncrasies in the measurement that would arise due to source incidence. So even if, say, I find a headphone that perfectly matches the sound measured at my EEP with the microphones of a neutral speaker in-room, when I actually listen to this headphone it likely wouldn’t sound the same because my brain is bringing different processing to the table.