Digital terrestrial and satellite radio are only dabbling in surround-sound music, but people eager to hear more music in surround can turn to DVD-Audio and Super Audio CD (SACD) players and changers. Both play CD-size DVD-based 5.1-channel music discs that deliver surround-sound music with fidelity far exceeding CD’s potential, thanks in large part to significantly higher data-storage capacities.

DVD-Audio and SACD discs outperform CDs in every respect. The DVD-based formats provide a resolution and clarity that captures the subtlest nuances of a live performance. Even more compelling is their ability to deliver multiple music channels through a surround-sound speaker system, creating a sense of realism lacking in two-channel recordings. As a further enticement, both formats display song titles, lyrics, graphics, background information about the band, other text information and multiple still images on a connected TV screen. The DVD-Audio format adds the ability to store music-video clips in DVD-Video format.

DVD-Audio and SACD surpass multi-channel DVD-Video discs in sound quality, largely because DVD-Video uses lossy perceptual-coding technologies to compress audio by as much as 12:1. DVD-Audio and SACD, in contrast, use lossless audio-compression technologies.

Niche Status
Despite their sonic potential, DVD-Audio and SACD discs haven’t achieved mass-market acceptance, but they are enjoyed by hard-core following of audiophiles and have settled into niche status.

Marketers cite several reasons for the formats’ niche status, including divided support among hardware and software companies and the rise of compressed-music formats such as MP3, which captured the imaginations of consumers more than DVD-Audio or SACD ever did. Another reason is changing consumer music-listening habits. Home audio sales were once driven by enthusiasts who purchased a refrigerator-size rack of components installed in a room where audiophiles sat intently in one spot while they listened to music. Now, most people listen to music as background in the home while engaged in other activities, so they’re unlikely to sit in the surround-sound “sweet spot” for any prolonged period of time to enjoy one of multi-channel music’s chief attributes.

In addition, consumers have few opportunities to enjoy multi-channel music on the go. Few car stereo systems, for example, offer DVD-Audio playback. None offer SACD. OEM and aftermarket car audio suppliers waited for demand to grow and for the disc-mechanism technology to evolve to withstand the rigors of the car environment. Then they lost interest when home-side demand didn’t meet their expectations. Aftermarket car audio suppliers also saw their core teenage and young-adult customers opt for systems that play MP3-CDs and connect to MP3 portables.

Software Availability
Many music companies also lost interest as they focused on fighting rampant illegal sharing of MP3 music files and tried to develop ways to harness compressed-music technology to meet customer demand. As a result, new SACD releases are available largely from small, independent labels, and the major labels have moved away from offering dedicated DVD-Audio discs to hybrid CD/DVD DualDiscs, which feature a CD layer on one side and a DVD-Audio or DVD-Video layer on the other side.

By early 2006, the number of DVD-Audio titles in the U.S. stood at 598, according to Muze, which compiles databases of entertainment product information for retailers. The number of SACD titles available in the U.S. stood at 1,213, Muze added.

The number of SACD titles available here, however, might be higher than that. Worldwide, the number of SACD titles grew by about 800 to about 3,500 at the end of 2005, and most of those were available in the U.S. as local releases or through import distributors and specialty online retailers, according to www.SA-CD.net, an online SACD resource.

Dual Disc Growth
Since the first Dual Discs appeared in late 2004, the number of titles grew to an estimated 200 at the end of 2005, Sony BMG has said. They’re priced competitively with standard CDs. About nine million DualDiscs were sold in the U.S. in 2005, the company estimates.

Music companies see DualDiscs as a way to reenergize sales of traditional packaged music media in the music-download era by offering extras such as surround sound, music videos, concert footage, video interviews, photo galleries, Web links and lyrics.

The dual-sided discs feature a CD layer on one side and a single DVD-Audio or DVD-Video layer on the other side. The CD side can be played in almost all standard CD players but might not be playable in every CD player because the CD-data layer resides at a depth that differs slightly from a standard CD’s data-layer depth. They also might get jammed in some slot-load CD players because they’re slightly thicker than a standard CD.

Backward Compatibility
Compatibility, however, is a hallmark of the SACD and DVD-Audio formats. SACD discs, for example, are two-layer discs, and one of the layers can be reserved for standard CD audio. Consumers who buy such hybrid discs can enjoy them in high-resolution multi-channel on SACD players and in lower resolution stereo on existing CD players.

From the start, DVD-Audio discs have been backward-compatible with DVD-Video players because they offer duplicate music tracks in multi-channel Dolby Digital, the compressed multi-channel format used on DVD movie discs. Some DVD-Audio discs also feature back-up DTS Surround, an audio format used on select DVD movie discs.

To further stimulate interest in the two formats, suppliers have designed all of their DVD-Audio players and SACD players to play CDs. In addition, all home DVD-Audio players play DVD-Video discs, giving rise to the term DVD-Audio/Video (DVD-A/V) player. Most SACD players also play DVD-Video discs.

Many consumer electronics brands offer so-called “universal” players that play DVD-Audio discs, DVD-Video discs, SACDs and CDs. Universal playback is available in select HTiBs. Other HTiBs play only one format or the other.

Multi-channel Downloads
Consumers who’ve made the transition from physical media to downloaded music can download select songs in multi-channel surround. One site, Music Giants, plans in 2006 to download 5.1-channel music to PCs and to hard-disk-drive (HDD) music servers sold through custom-A/V installers. Another site, instantlive.com, began in early 2006 to offer downloads of live concerts that it records and mixes in stereo-compatible SRS Circle Surround 5.1, which can be decoded by home and car stereo systems incorporating Circle Surround II matrix decoders or other types of matrix-surround decoders. Some of the songs became available on the Napster download site in late 2005.

With the addition of an SRS TruSurround XT “virtual-surround” adapter, MP3-type headphone stereos deliver the multi-channel effect through stereo headphones.