Based on the same flat-panel speaker technology as the Wharfedale LoudMan, the Sonic Impact SI-5 Generation 2 speakers snap together for travel and come apart for listening. Separated, they're a pair of fiberboard panels propped up on a stand; you use loose cables to connect the panels to each other and to your portable device.

Sonic Impact adds a bass booster to its speakers, and the sound is a little richer than that of the LoudMan system. Bass guitar sounded terrific, and the mixes on our electronic and heavy-metal tracks were well balanced. The Generation 2's audio range, from roughly 170 to 5,000 Hz, was about the same as the Wharfedale's, given the imprecision of our tests, but the low end was pumped up a bit. Expect 20 hours of use on 4 triple-A batteries.

The Sonic Impact SI-5 Generation 2 makes a fine pair of budget speakers for a small to medium-size room. Although they don't sound quite as good as the inMotion system, they cost only half as much—and that's a compelling feature.