This DVD changer outperforms many stand-alone CD players we've evaluated. Although lots of manufacturers tout the inclusion of 24-bit audio digital-to-analog converters, the SD-4109X demonstrated some of the most accurate sonic dynamics we've encountered in a DVD player. Most DVD-video players exhibit a sharp digital edge on every kind of music, from trumpets to cellos. With the SD-4109X, nylon guitar strings seemed to float across our listening room "sound stage," fading slowly with each chord change--and that's without utilizing the player's built-in High Definition Compatible Digital (HDCD) decoder.

HDCD is a music recording format that takes advantage of 20- and 24-bit encode/decode systems, resulting in superior CDs that offer higher resolution and wider dynamic range. Every HDCD we played was clean and articulate. Although it stands to reason that 20- and 24-bit discs might exhibit the sterile sound common to many digital transfers, HDCD actually adds warmth to the CD format. With it, it seemed like long-gone blues singers were serenading us in our darkened listening room. We applaud Toshiba for incorporating HDCD into an affordable multidisc player.

As for video, the SD-4109X performed flawlessly. If you're a home-theater enthusiast who is not impressed with the SD-4109X's 10-bit video digital-to-analog-converter (DAC) because you've grown accustomed to this now-basic spec, you should know that not all DACs are created equal. Action sequences, which cause some DVD players to skip or freeze up momentarily due to compression issues, were not a problem with the SD-4109X. Challenging frames that give most players the moiré jitters were barely noticeable on this Toshiba.

Since the SD-4109X performed impressively on music CDs, it's no surprise that it also outclassed most DVD players on 5.1-channel surround-sound material in both Dolby Digital and DTS modes. Subtle low-frequency effects came through on our test subwoofer as genuine sonic vibrations, compared with some other players that can't seem to accurately reproduce the low end. Even those high-frequency sound effects present in explosion scenes and train wrecks were more convincing on the Toshiba--especially on DTS discs, which offer a lower compression scheme than Dolby Digital, with a wider range of audible sounds on some movies.

Based on our experience with multidisc CD changers, which are often inferior to their single-disc cousins, we were pleasantly surprised that Toshiba elected not to compromise sound dynamics and video resolution in favor of the multidisc tray and other frills. The SD-4109X is packed with the kinds of features you would expect from a six-disc changer, including random-track play and other programming options. Its onscreen display is comprehensive yet simple, allowing you to select menu and subtitle languages, change surround-sound selections, and activate the black-level expansion switch. This last feature improves contrast levels, and although we usually resist manipulating our video display from the source component, we did notice that the black-level adjustment improved the edges of characters and objects on screen, adding a slight dimension to the picture's overall depth. We also liked the inclusion of an onscreen video bit-meter display, as well as the component-video outputs.