MidnightSun
100+ Head-Fier
I don't have the context for the rest of this but the excess bass on the Harman IE target is at least in part due to the 711 couplers lacking the accurate acoustic impedance. This was also confirmed in Dr. Olive's recent talk at CanJam NYC, as the IE work is currently in the process of being redone on the more accurate B&K 5128. Of course the other issue is there's no reason to expect a difference between in ear preference and over-ear preference, and if the methodology had been the same we may end up with similar preference results for both. On the other hand, we also don't know how people would have adjusted the bass when presented with say... a population average baseline starting point.
TLDR: At the very least, Jude was right about the 711 couplers, and that's certainly responsible for this difference. But that doesn't mean there isn't something else going on as well with regards to the overall curve itself, namely the difference in methodology could be having an impact such that the IE result itself is an outlier.
Interesting... so this sort of implies that we don't actually need more bass with IEMs? Because I always had the opposite idea: to sound "neutral", the lower mids and bass can't be a straight, flat line on a 711 coupler, whereas it's generally considered to be ideal on a headphone.