The Sonos ZonePlayer S5 is a fabulous addition to the multi-room Sonos Digital Music System, even if the company’s engineers did make some sonic compromises in the name of delivering an all-in-one model at a friendlier price point.The passive ZonePlayer 90 sells for $350, and the ZonePlayer 120—which features an excellent integrated 55-watt-per-channel amplifier—goes for $500. The ZonePlayer S5 packs both an amplifier and speakers, and is priced at just $400. This low price, coupled with the company declining our query about the amp’s power and total harmonic distortion specs and the material used in speaker fabrication, leads us to believe that Sonos is looking for a bridge to a more proletarian market.