Headphone break in?

I believe everything in the audio world will benefit from break-in but in your scenario, I don't know from experience how long it will take. I'm sure others don't believe in break-ins and you are entitled to your opinion.

I had purchased a slightly used set of Hifiman HE1000V2 headphones that developed an issue, Hifiman replaced with a new pair under warranty and I have to say it took a good while for them to come on song to the point of me not enjoying them till they burnt in. Enjoy the music

I have found that my headphones, Focal Stelia, Meze Elite, ZMF Verite closed, and others all benefit from break-in time. I usually noticed differences in 25 hour increments with them really settling in around the 200 hour mark. I would leave them plugged in to my amp and run them continuously for a couple of days to help the process. 

It depends; I've had a lot of headphones and some sound really good, if not their best, right out of the box, and others I've gotten that sounded so bad out of the box that I was ready to send them right back, but after letting them break in for about 150-200 hours, they sounded like they were supposed to... 

Yes. Headphone burn-in is a real phenomenon.

I made a burn-in clip years ago that works with all headphones, regardless of their driver type/technology. WARNING - take off your headphones FIRST as this will not sound good! It uses each of the important types of noise (white noise, pink noise, etc.) these in turn influence the movement of the driver units completely by the end of the video.

@hsc3md

No need to play 100+ hours. My condensed burn in-in clip places enough strain on the driver units to have them conform to the designers engineering standard.