Auro-3D® is the next generation three-dimensional audio standard. It provides a realistic sound experience unlike anything before. By fully immersing the listener in a cocoon of life-like sound, Auro-3D® creates the sensation of actually 'being there'. Thanks to a unique 'Height' channel configuration, recorded acoustic reflections are reproduced by these speakers and are heard naturally due to the fact that sounds originate from around as well as above the listener.
Once upgraded with the Auro®-Codec Decoder, the Denon AVR-X7200W and AVR-X5200W are capable of decoding the original Auro-3D® mix and playing back an Auro 10.1 channel configuration (including "Voice of God" channel). The AVR-X4100W can process an Auro 9.1 channel configuration for full height layer capability.
The Auro-3D Upgrade can be purchased for $199.
here for upgrade.