I have the PX7 carbon edition. Im aiming to dona review here soon as i can. The carbon and non carbon sound very very different. They use a different firmware. My carbins came with v1.1 installed, and the sound would have been the same as the standard px7. The vocals were very recessed on many tracks, and lack of energy on some drums etc. The bass was often muddied but very strong. In short they were fantastic for some albums (david Bowie's earthling, and electronic music, and some rock) and lacking on many other albums. They were good for low level listening because of the boosted bass.
After 3 weeks of listening i activated the b&w app and the headphones auto updated to V1.2. The sound changed instantly. The muddied bass was gone and the recessed vocals totally gone. I imagine many adiophiles would love this new sound. Howver, i didnt, and still miss the old sound for electronic music and some others. I am currently speaking to b&w about this and am getting a replacement set as they think the firmware may not have been implemented properly, but i doubt this very much, but will try.
They absolutely need to provide these cans with an EQ adjuster.
For low level listening the new firmware is rwally quite bad. The music lacks weight and any meat on the bones. At higher volumes it gets better, but gets nowhere close to the old firmware, and music often sounds lacking in body. Such a shame. These are great headphones, but so frustrating that the EQbe adjusted for your needs.