Headband replacement for the HE4XX and other things... : r/headphones
THE Ultimate Step-By-Step Hifiman Headband Replacement Guide from OLDSTOCK Hifiman (HE-4/5LE/6/400/500) into the NEWSTOCK (HE-400i/560) !!! | Headphone Reviews and Discussion - Head-Fi.org
Massdrop x HIFIMAN HE4XX Measurements and Impressions | Super Best Audio Friends
THE Ultimate Step-By-Step Hifiman Headband Replacement Guide from OLDSTOCK Hifiman (HE-4/5LE/6/400/500) into the NEWSTOCK (HE-400i/560) !!! | Headphone Reviews and Discussion - Head-Fi.org