|Min OS X: 10.1.5 Requires: USB Port|
The home theater is now a reality. The migration of surround sound from theater to home began less than a decade ago, when the first AC3-ready receivers appeared on the market, with support for S/PDIF digital audio connections over coaxial or optical cables. The next step was the rollout of the DVD format and the supporting Dolby Digital and DTS surround sound technologies. It wasn't long before DVD drives began to appear in computers, which have increasingly become the center of home entertainment systems over the last few years.
While it has been possible for several years to watch DVD movies on the Mac, the Mac home theater experience has been limited by an inability to access the surround sound capability of the DVD format. Until recently, that is: with the release of Panther (Mac OS X 10.3 -- the latest incarnation of Apple's modern beast), Apple has finally lifted this limitation, offering support for S/PDIF audio output in the included DVD Player application. Now all you need is an optical or coaxial S/PDIF audio output...
Enter the M-Audio Sonica, a compact USB-connected device that offers optical audio output, as well as an 1/8" analog output. The Sonica has actually been available for over a year now, but with the lack of S/PDIF support in Apple's DVD Player, the only way to get 5.1 audio from your Mac was via the VLC video player (which is still under development and has yet to reach a final 1.0 release) -- or, for those still in the dark ages of Mac OS 9, the Wired4DVD PCI card & DVD playback software, which was discontinued awhile back and will never be supported in OS X.
The purpose of the Sonica is basically singular: to provide digital audio output for your Mac. Because it's a USB device, it can be used with all Macs that have a USB port; the small size of the device makes it an ideal solution for surround sound on an iBook or PowerBook. The optical output supports 16- and 24-bit audio at sample rates up to 96 kHz.
It may be obvious to some, but it's nonetheless worth mentioning that the Sonica alone isn't going to transform your computer into a home theater; you'll still need a 5.1 receiver and speaker system. In addition to the many surround sound-capable home stereos on the market, there are also 5.1 speaker sets made specifically for computers. It really doesn't matter what you decide on, as long as it has an optical input and supports Dolby Digital or DTS (or preferably both, as is most often the case nowadays).