Also known as the Sonos Loudspeakers, these attractively styled bookshelf speakers deliver very good sound from the ZonePlayer ZP120's built-in 50-watt amp, and they're downright affordable at $179 per pair. If you purchase the Sonos Introductory Bundle with Speakers from Sonos.com, you'll get two ZonePlayers, a CR100 remote, and two pairs of SP100 speakers for $1,499. That's not exactly chump change, but it's pretty reasonable compared with custom-installed multizone systems such as those marketed by Escient and others.
At 11.3 by 6.4 by 7.6 inches (HWD), the Sonos SP100 speaker cabinet is quite compact. Because the speakers have rear ports, they should be installed on stands rather than placed in a bookshelf or mounted on a wall. The medium-density fiberboard cabinets feature an unobtrusive gray vinyl coating accented by removable black cloth grilles. Around back, each speaker has two robustly constructed spring-loaded binding posts that accept bare wire and banana plugs. Sonos thoughtfully supplies two 10-foot, 14-gauge white speaker cables with bare wire ends.
The SP100 is a two-way speaker, meaning it has crossover circuitry that sends the appropriate frequencies to each of its two drivers. Each magnetically shielded SP100 includes a 1-inch alloy dome tweeter and a 5.5-inch polymer woofer. The speakers are rated down to only 75Hz (plus or minus 3dB), and listening sessions confirmed that they don't output deep bass.
We spent nearly two weeks with the SP100 speakers, listening to them almost every day. Right off the bat, the speakers' relatively bright, revealing treble performance and tight--albeit not deep--bass response caught our attention. In essence, the SP100 speakers reminded us of good studio monitors, designed to reveal the sonic subtleties of music during the recording and mastering processes. In comparison, a pair of well-respected Paradigm Titan bookshelf speakers produced smoother but less revealing treble and delivered rounder, less punchy bass performance. Basically, the SP100s are a bit edgier.
When we fired up Buena Vista Social Club's Afro-Cuban track "Chan Chan," the vocals and guitar had lifelike midrange texture, the trumpet glistened with crystal-clear but not overly bright treble, and the soundstage displayed convincing depth. The bass line was certainly audible, but it didn't have the same presence we've heard with bigger speakers.
With Bass Factory 808's electronic "Woofer Warm Up," despite not being able to reproduce the track's lowest frequencies, the SP100 speakers never got sloppy and delivered tight, punchy bass the whole way through. Because the ZonePlayer has a subwoofer output, you can easily add a sub to the mix if you want more bass; however, Sonos currently doesn't offer one. It's worth noting that the ZP120's built-in amp was able to drive the speakers to loud but not excruciating volumes. On most occasions, we listened with the ZonePlayer's volume at half to three-quarters of the maximum setting.
Bottom line, the SP100 outperforms many comparably priced bookshelf speakers. Sure, you could use just about any old set of efficient speakers with the ZonePlayer, but the SP100s are a competitive option that also happen to match the look and feel of the Sonos system.
Editors' Note: This review has been updated to reflect changes in the Sonos product line for 2009. The rating has also been adjusted to reflect changes in the competitive marketplace.