Announced in Summer, 2003, DualDisc is yet another a/v format, and delivers CD audio on one side, and a DVD on the other. Beginning in February, 2005, many titles, some old, some new, will be available on DualDisc for the first time, with bonus material on the DVD-side.

However, the creators of the CD and DVD standard specifications won't allow their familiar logos to be used with the DualDisc. At least 8 audio manufacturers (MarkLevinson, Marantz & Sony Europe, Toshiba, Sony Electronics, Pioneer Electronics, Onkyo Electronics and Sony Computer Entertainment America) have released consumer warnings, stating that since the discs do not meet the Compact Disc Digital Audio specification, consumers should not use them in their products until the manufacturers' R&D departments can certify that the discs are suitable. In fact, some of these manufacturers will not cover damage caused by the discs.

The concerns.

1. CDs are 1.2mm thick and are allowed to be up to 1.5 mm thick, allowing for size variations in manufacturing. DualDiscs are 1.5 mm thick and it's feared that by being at the absolute outer edge of thickness, they may jam in some CD and DVD players. This is by far the biggest single concern since it may lead to physical damage of discs and players.

2. Apparently, the non-DVD side (can't be called CD-side) can only hold 60 minutes worth of music.

3. Since the DVD side is mated to a CD-side, the DVD side is necessarily single-layer and can only hold half of the information of a dual-layer DVD. Most 2-hour or longer DVDs are dual-layer. This compromise in the amount of data that the disc can hold may explain why the "Reunited" documentary on the new Judas Priest "Angel of Retribution" DualDisc is 10 minutes shorter than on the separate DVD that comes with the limited edition CD version of the album.

DualDisc now competes with SACD and DVD-A, neither of which became very popular with mainstream consumers.

What Is On the DVD-side of DualDisc?

You may see an Enhanced album audio, 5.1 surround sound, music videos, artist interviews, behind-the-scenes footage, documentary films, photo galleries, lyrics, computer-ready digital song files, and Web links.

To take full advantage of DualDiscs's DVD side that feature surround sound music, you¹ll need a 5.1 channel surround system.

What Is Enhanced Audio And Surround Sound?

The DVD side of the DualDisc offers superior audio. Many DualDiscs include surround sound mixes that have been specially created during the recording process. When listened to on a 5.1 channel surround system, the result is a rich, three-dimensional musical experience.