Audio-Technica ATH-M50x vs beyerdynamic DT 900 Pro X

The M50x is the pair most people land on when they ask for studio headphones, and the practical case for it over the Sony is the cable. Three leads are supplied (coiled, long straight, short straight) and each locks into the cup with a quarter turn, so a damaged cable is a two-second swap. Over a five-year ownership that is the difference between a working headphone and a drawer headphone.

The 45mm drivers give it more low-end weight and a more relaxed treble than the MDR7506, which makes it usable as an everyday headphone rather than only a work tool. Isolation is good, the cups rotate flat and fold in, and the pads are a stocked replacement part.

The tuning is the caveat for critical work: there is a modest bass lift and a slight upper-midrange dip, so it is a headphone you can mix on once you have learned it, not one that is neutral out of the box. Clamp force is high when new and takes a few weeks to relax, and the cups are on the small side, so larger ears sit against the driver baffle rather than around it. Owners consistently report the pads flattening and cracking after a couple of years of daily use.

The DT 900 Pro X is beyerdynamic's answer to the two things people complained about for twenty years. The 250-ohm DT 990 Pro needed a real amp and had a fixed cable; the 900 Pro X uses the STELLAR.45 driver at 48 ohms, which any interface headphone output can drive, and puts a locking mini-XLR connector on the left cup with two cables supplied.

As an open-back it is the pick for judging reverb tails, stereo placement and where instruments sit relative to each other, all of which are harder to hear inside a closed cup. The tuning is more even than the DT 990 Pro it replaces: still a beyerdynamic presence lift, but without the sharp treble peak that made the older model punishing on harsh material.

The limits are structural. Being open-back, it leaks freely, so it cannot be used anywhere near a live microphone and it is not a shared-office headphone. The velour pads are comfortable but hold heat less well than they look, and they compress over time, which changes the seal and therefore the bass. And at this price the frame is still plastic with a metal headband core, which is durable but does not feel like the money.