Pros: Tight bass, compact design, wireless, attractive
Cons: It only works in conjunction with Sonos gear
Last week I set about reviewing a pair of Sonos Play:1 speakers as well as the Sonos PlayBar soundbar. Sonos is a wireless audio system, a pairing of software and hardware that brings home-audio setup and operation into the virtual realm and makes it very fast and easy. While you can use products like the Connect and Connect:Amp to interface with an existing stereo system, you can also build systems using Sonos hardware, including its line of Play speakers and the Sub.
The Sonos Sub features a novel dual-opposed driver, ported design
Each Sonos speaker is self-powered and wireless, including the Sub. All Sonos components include an Ethernet port for wired installations, but the real appeal is the combination of wireless functionality and the software that runs it.
The first thing you notice about Sonos gear is the modern, minimalist design. The Sub has only one button on it, and the cabinet is as functional as it is attractive. The two drivers face each other, while radiating into a space in the center of the cabinet. There are also two ports, which vent into the same space. The design is surprisingly effective and potent for its size. Weighing in at 36 pounds while measuring a mere 15 x 6 x 15 inches, it is remarkably easy to find a spot where the Sub both fits and sounds good.
One of the coolest things about Sonos is how quick and easy it is to configure components. Pairing a Sub with either a pair of Play speakers or the PlayBar soundbar was a matter of plugging in the Sub, launching the Sonos app, and pressing a button on the Sub itself. Within seconds, the app played a bass tone through the Sub and prompted me to choose the Sub's phase. Then the app gave me an opportunity to adjust the Sub's level. It takes less than two minutes to set up a Sonos Sub, and that's a record in my book.
I put the Sub up against my own DIY subs, the Sump Basins. My two subs each utilize a pair of dual-opposed 12" drivers, and each one receives 1000 watts of power from a Crown XTi-2002 amp—in other words, the Sump Basins achieve reference-level playback all the way to 20 Hz and below. The Sonos cannot dig that deep due to its compact size and ported design; there are physical limits to how low such a sub can play. I measured usable output to about 25 Hz, and from 30 Hz on up I found it was a very capable sub.
I measured usable output as low as 25 Hz on the Sonos Sub
What I really like about the Sonos Sub is the way it sounds. Even though it can't hit 20 Hz, it produces tight, visceral bass. Wireless or not, it is one of the better compact subwoofers I've heard. With most music, its capabilities are sufficient to create a sense of realism that's missing from most budget subwoofers. When used as part of a 5.1 system along with the PlayBar and a pair of Sonos Play:1 speakers, the Sub delivered a proper cinematic rumble and thump at a satisfying volume.
Because the Sub is both wireless and compact, it is easy to find a home for it based on aesthetic concerns—it is easy to hide—or positioned for optimal bass performance. One of the best methods for determining the best place to put a subwoofer is the crawl test. In a nutshell, you place a sub right where you plan to sit—the main listening position. Then you crawl around the room listening to a bass tone until you find the spot where the sub sounds best. Wherever that spot turns out to be—there could be more than one—is the optimum spot for the sub itself. With the wireless Sub, that whole process takes mere minutes.
With the Sub properly positioned—in my case, against the right wall, about three feet out from the front corner—I set about listening to both musical and cinematic sounds. First things first: the Sonos hardware can’t compete with my wired rig—a Pioneer Elite SC-55 AVR-based 7.1 system with the aforementioned Sump Basin subs and SP-FS52 tower speakers handing the surround and front-height channel duties. A pair of self-powered Monster Clarity HD One speakers serve as the mains, with no physical center speaker—I use the "phantom center" approach. The system measures flat from 20-20,000 Hz.
Considering what it was up against, the Sub performed admirably. It is easy to forget exactly how deep 20 Hz is—for the vast majority of music and movie content I played, the Sub provided all the bass I could want. And it was articulate bass, with every note well defined—quite the opposite of "one-note bass." With the Sub, it's definitely about bass quality over quantity, but I'm sure you could still use it if you want to be evicted from an apartment.
The most important thing a subwoofer can do is disappear into the mix, integrating with speakers in a seamless manner. That's where the Sub succeeds. Whether used with the PlayBar as part of a surround system, or with a pair of Play:1 speakers in the kitchen or on a desktop, I found that the Sub simply disappeared into the mix. The dual-opposed design cancels all cabinet vibrations, so the Sub never, ever calls attention to itself. I also found that it did not falter, even when pushed to reference levels for movie watching—for instance, it handled the bass-rich soundtrack of Oblivion with aplomb.
Sonos products are a lot like Apple gear—a high-performance, integrated system featuring slick design and a price that is sufficiently high to qualify as "luxury," but not entirely unaffordable. It's easy to forget that Sonos is a wireless system, because it operates so reliably. The Sub is the key to getting the most out of Sonos Play speakers and the PlayBar. If it were not a great-sounding subwoofer, the entire Play line of Sonos speakers would suffer as a result. Fortunately, that's not the case. Instead, the Sub is the essential foundation of a wireless hi-fi system that's good enough to satisfy a bass addict like me.
I would like to offer my thanks to Bob Cole from World Wide Stereo for helping make this review possible. I asked him if I could audition the Sub at home, however he had none in stock—except the demo unit in his showroom. He loaned me that unit, on the condition that I return it before Black Friday.