SX Pro automatically converts stereo into 5.1 Surround Sound

Best known for its development of the MP3, the Fraunhofer Institute for Integrated Circuits IIS is set to make another significant contribution to audio later today when it begins previewing a new technology to create 5.1 surround sound from existing stereo content at the Audio Engineering Society Convention in San Francisco. Fraunhofer IIS will demonstrate the high audio quality and high degree of creative control offered by the new SX Pro processing, which will be available for integration in software, consumer electronics, and professional hardware by the end of 2006.

To create surround sound from regular stereo music, SX Pro analyses the audio signal and identifies characteristic sound elements. An intelligent algorithm redistributes these elements to create a natural surround sound listening experience without adding artificial reverberation.

The center channel is smoothly integrated without altering the original stereo sound stage, providing a stable front image even for off-sweet-spot listening. The surround channels consist of the ambience-like sound components of the stereo material, greatly enhancing the user envelopment, similar to a discrete multichannel surround sound listening experience - with only two channels as source material.

Bernhard Grill, head of the audio department at Fraunhofer IIS, says: "SX Pro offers exciting new possibilities when it comes to playing back stereo content over surround setups as its intelligent algorithm provides a high degree of control over the resulting sound image."

SX Pro is the best choice for any application where twochannel legacy content is transmitted to or played in a multichannel environment. For example, consumers may enjoy high quality playback of their existing stereo music on multichannel receivers and car audio systems that have integrated SX Pro processing.

The incorporation of SX Pro processing into professional media production and audio editing tools will allow surround versions of existing stereo source material to be produced using the creative control over the upmix process offered by SX Pro. Radio broadcasters offering new surround services may also convert their existing content to surround sound automatically, to match the presentation of new surround tracks.

Unlike prior approaches, the SX Pro technology offers a stable sound field during fast changes in content, and consistent, distinct positioning of audio sources, offering a realistic substitute for true 5.1 mixes when they are not available.

At the AES Convention, SX Pro will be demonstrated as PC software and as a DSP hardware implementation. The PC software allows users to switch between different optimized presets to change the spatial sound image. The DSP hardware implementation accepts any two-channel PCM audio stream and performs a real-time stereo to 5.1 upmix.