Every Dynamic Driver I ever had HP and IEM was better after 24 hours of burn in. Just my experience so far.
I would say the same thing-- but the thing is it's just as true of sets I've gotten used as new sets...at least in my experience. Case in point. I've had the Dorado 2020 for the better part of a year. I sent it in for a test and CFA wound up sending me a brand new unit. I bought my original Dorado 2020 used so I didn't have the opportunity to experience any non-brain burn-- but I did find the sound getting better and better to my ears in my first days and weeks with it. When I got the new one a few days ago and plugged it in I recognized it as a rare opportunity to add weight or not to the burn in question-- and what I found was that this new Dorado sounded exactly like I remembered my old one sounding. Could this have just been my brain filling in the gaps? Perhaps...but that's what muddies this whole question a little...ie., the capacity of the mind to delude itself. Ultimately in this rare instance I'm somewhat sympathetic to the measurement fascist position in that absent something measurable here it will be difficult to prove conclusively one way or the other.