This month's Sound & Vision had a few articles on DualDisc and surround formats.
DualDiscs do not meet redbook guidelines and can damage your player.
Harman International has made it policy that DualDisc use voids the warranty. That means the following brands which fall under the Harman umbella have no warranty w/ DualDiscs Harman Kardon, JBL, Infinity, Revel, Audioaccess, Lexicon, Mark Levinson, Madrigal Imaging, and Proceed.
Other companies that have advisories against using DualDiscs while they study them include; Pioneer, Toshiba, Onkyo, Marantz, and Sony. In Sony's case their computer entertainment division said "some DualDisks may be unreadable on its Playstation consoles-----And it also warned that, for certain models, playing a DualDisc when the console is in a verticle position 'may damage the disc, the console, or both."
