ATC's Concept 2 is a premium multichannel system that reproduces music and home-theater soundtracks with grace and accuracy. Though not inexpensive, it lives up to its cost. In a suitable listening environment, it sacrifices very little to much larger loudspeakers, including ATC's own. I know of no other 5.1-channel system, passive or active, that has attained this level of refinement, dynamism, and sheer style in such an efficient package.