The headband of the R7DX is tension-free, as it does not fit hermetically sealed headphones. So I changed HE400SE headphones and headbands, and I got a very satisfactory result. | Drop
THE Ultimate Step-By-Step Hifiman Headband Replacement Guide from OLDSTOCK Hifiman (HE-4/5LE/6/400/500) into the NEWSTOCK (HE-400i/560) !!! | Page 12 | Headphone Reviews and Discussion - Head-Fi.org
How do you deal with headband hot spot? - DIY Headphones - HifiGuides Forums
Replacement Headband Cushion For HIFIMAN HE4 HE400 HE5 HE5LE HE500 HE6 Top Head Band Pads Headphone Headset
Hifiman HE400SE mods - Do It Yourself (DIY & Mods) - The HEADPHONE Community