DAB Surround: The new MPEG surround standard compresses the six channels of a surround piece of music in such a way that they require no more memory than a compressed stereo signal. Another advantage: Radio stations save themselves the expensive parallel broadcast of stereo and surrounds. Because when the original 5.1 sound is compressed, a stereo mix is automatically created and parameters are determined thatKlang describe.
Only a few kilobits per second are required for these parameters. The transmitters then transmit the stereo signal together with the parameters. While previous receivers ignore this additional data and play back the stereo signal as usual, future DAB surround receivers should play back the original 5.1 sound. According to the IIS (Fraunhofer Institute for Integrated Circuits), even oldies can be “ennobled” with surround sound. For this purpose, the IIS has developed the SX-Pro process, with which broadcasters can process stereo content in real time in such a way that it fits harmoniously into a 5.1 transmission.
To do this, the sound image of the stereo music signal is analyzed and the middle and rear channels of a 5.1 system are integrated: This increases the range of optimal listening and the sound image becomes more stable. This means that even the oldies from the 70s or well-known older classic stereo concert recordings can be broadcast in 5.1 surround in the future without any problems.