Sennheiser CX 400BT Impressions:
Sub-bass: Sub-bass is elevated and on the tighter/faster side, with good texture. Does rumble but not that much and extension could be better.
Mid-bass: Mid-bass is the focus over sub-bass, but fortunately still on the tighter side, speed is decent as well as texture.
Lower-mids: male vocals tonality is quite good but slightly recessed.
Upper-mids: female vocals tonality is too warm and slightly recessed as well, not shouty at the slightest.
Treble: extremely tame/relaxing and fatigue free treble, very smooth and a very safe tuning. The mid-treble area is the reason why this isn’t overly dark for me and just ends up being a very warm treble and upper-treble does have some air in it.
Overall: A pleasant surprise after my experience with the badly tuned FIIL T1 Lite. Looks like my TWS journey might not have ended.
(using the Final Audio Type E tips)