The Hifiman HE400i Reference 4 profile sounds too bassy. Other users have comments similar observations on Head-fi. The frequency response of the HE400i and HD600 within Reference 4 does not match relative measurements from other entities. Reference attached images. I wonder if the amp used by Sonarworks when creating headphone profiles cannot adequately drive planar magnetic headphones.
Please look into improving the Hifiman HE400i Reference 4 headphone profile.