The MMX 2 and MMX 300 are first and foremost pure stereo headsets, i.e. headsets with one loudspeaker on each side of the headphones.
Nowadays, surround sound is ideally simulated using the so-called "head-related transfer function" so that a realistic surround sound quality can be reproduced on stereo headsets.
To achieve this, the auxiliary player, e.g. the PC’s sound card, must have the corresponding technologies, e.g. "Dolby Headphone".
In the high-end sector, beyerdynamic offers a stand-alone system: Headzone H 1.