Now that Logitech's excellent Z-5500 Digital 5.1 speaker system has been around for a few years, it's available for considerably less than its original $400 asking price. But desktop owners looking for another option now have an even more affordable alternative in the form of the company's just-announced G51 surround-sound system. The all-analog 5.1 speaker system features stereo and 6-channel inputs, the latter matching the outputs found on nearly all surround-capable PC sound cards. The G51 features two matrixing modes--one for games and one for music--that can synthesize a 5.1 surround track from a 2-channel stereo source (similar to Dolby Pro Logic II or THX Neural). In addition to the 5-inch subwoofer and 2-way satellite speakers, the G51 features a convenient desktop control pod with microphone and headphone jacks and dual discrete mute buttons, as well as full speaker volume controls. The G51 is scheduled to hit stores in October for $200.