The limited edition ATH-M50xBB has been discontinued. Please see the ATH-M50x for a similar model. Pure. Professional. Performance. As the most critically acclaimed model in the M-Series line, the ATH-M50 is praised by top audio engineers and pro audio reviewers year after year. Now, the ATH-M50x professional monitor headphones feature the same coveted sonic signature, with the added feature of detachable cables. From the large aperture drivers, sound isolating earcups and robust construction, the M50x provides an unmatched experience for the most critical audio professionals.