That's nonsense. That's like saying it's wrong for God or whatever to make human beings with different sized ear canals. If a measured peak changes position from 9kHz to 12kHz because of tube length, and many trained ears don't hear it, then it's simply not there. This is not to say that a good swath of that mid-treble region cannot be bumped already. As for B2 or other deep insertion IEM, I don't hear a peak shift with deep insertion. What I hear is an attenuation of the highs relative to the lows. I know the difference between a peak 8kHz and 12kHz. Shoving the B2 deeper didnt make the ssss into a zzzz, it just made it less bright. Similar with UERM (customs vs less deep universal), MEE P1, and ER4S. Never heard the measured peaks change frequency based on insertion depth, although I am convinced there is a treble peak on ER4S and upper mid peak on P1. Now this is absolute nonsense. I don't hear 7-9kHz peaks caused by my pinna and ear canal on flat speakers in a damped room. Never have and probably never will. Brain has inverse HTRF function that takes care of this. You are sure you are not hearing these peaks from your Voxactiv wide banders?