Sonos Sub adds big bass presence

Sonos, maker of a variety of excellent multi-room music systems, has added a high-end bottom end to its line up of powered speakers—the $699 Sonos Sub. More than just a subwoofer, the Sub incorporates into existing powered Sonos configurations to add a rich bottom end to your streaming music.

(Note: I’ve reviewed the final shipping version of the Sub, but Sonos expects to ship the Sub to customers starting June 30. A black matte version will also be available in September for $599.)

Parts and ports

The glossy piano-black subwoofer is anything but a lightweight. With dimension of 15.8 (height) by 6.2 (depth) by 15 (width) inches and weighing in at just over 36 pounds, the Sub is a substantial hunk of speaker. Or, more specifically, two force-canceling speakers placed face to face, two Class-D digital amplifiers, and two acoustic ports in a rock-solid cabinet. Attractive though the Sub is, you needn’t leave it out in the open. As bass frequencies are non-directional and the speaker does its job whether standing up or lying down, you can shove it under a couch or behind a cabinet.

The Sub bears a power port, an ethernet port for optionally connecting it to a home network (it contains wireless circuitry for joining a Sonos mesh network), and a single button, which you press to connect the Sub to an existing Sonos setup. It has rubber feet on the bottom and the package includes felt feet for protecting floors and furniture.

Easy setup

To configure the Sub to join a Sonos network, simply fire up a Sonos controller—one of Sonos’ hardware controllers or a controller app on your iPhone or iPad, Android device, or Mac or Windows PC—select the option to add a Sonos component, and push the Sub’s single button. The controller will add the Sub to the Sonos network and walk you through setup. During that process, you’ll be asked which Sonos gear you’d like to pair the Sub with if you have more than one Sonos zone in your home. It can be paired with the Connect:Amp, ZP120, ZP100 and powered amplifiers; and the Play:5/ZonePlayer S5 ( ) and Play:3 ( ). It doesn’t work with the non-amplified Sonos Connect, ZP90, or ZP80 units.

During configuration, you’re asked to conduct a couple of sound tests in the room in which you’ve placed the Sub and its paired components. The first plays a series of tones at two settings. You choose which is the louder (or choose No Difference if they sound the same to you). In the next test you have the option to adjust the Sub’s volume—in three increments up or three increments down from a medium volume. You’re advised that you want a sound that’s clear but not overwhelming. Tap a Next button and the configuration is complete. Overall, configuring the Sub is as easy as setting up any Sonos component (meaning it’s practically a dead cinch).

You’re not committed to playing the Sub at the volume you set during the initial configuration. Just access a zone’s settings and locate either the Advanced Audio setting in one of the mobile apps or the Sub setting within the Sonos application’s preferences on your Mac or Windows PC and you can adjust the Sub’s volume up or down. (You can also switch off the Sub here.)

How it works and sounds

When you play music through a Sonos system with the Sub attached, the system changes the frequencies coming from the non-Sub speakers. For example, if you’ve paired a couple of Play:3 speakers and added the Sub to that configuration, the Play:3s will leave the bass frequencies to the Sub and instead push mids and highs from their smaller speakers. If you later remove the Sub from that configuration, the Play:3s go back to playing bass frequencies in addition to the mids and highs.

How impressed you’ll be with the Sub depends on the equipment you use it with. I have a pair of old B&W DM7 mk2 speakers that are connected to a Sonos ZP120 amplifier. I love the sound of these classic speakers as they are, but added the Sub to see how the sound fared with more bottom end. For the most part, I needed very little volume from the Sub to round out the bass. Pumping it up to just over mid-volume made my test music (classical, rock, hip-hop, and jazz) sound too bass-heavy for my taste.

I then tested the Sub with a pair of Sonos Play:3s. For small speakers, the Play:3s sound quite respectable on their own, but when you add the Sub, you’ve really got something. Bass frequencies you don’t hear from the Play:3s leap out. Better yet, the bass isn’t flabby. You hear defined tones rather than just the woof you get from some subwoofers.

If your entire reason for buying a subwoofer is to take your internal organs to the brink of dislocation, the Sub mostly delivers. I pushed the Sub to its limits and it quite literally shook my living room floor. Had I downstairs neighbors, they undoubtedly would have banged on the ceiling with the heaviest implement they owned. The reason I qualify the description of volume and intensity with “mostly” rather than “entirely” is because the Sub didn’t cause glassware to fall from cupboards or the foundation to crack. But within the rational limits of those who can’t get enough bass (a tone I find unpleasant and unmusical), the Sub delivers plenty of pop.

Macworld’s buying advice

What makes the Sub attractive is its relationship with other Sonos components. Sonos’ engineers understand the capabilities of all those components and can tune Sonos powered-speakers so that they sound their best when a Sub is added to the setup. Therefore, if you own a couple of Play:3s or Play:5s and feel like the music coming from them lacks range and definition, adding a Sub could improve the sound greatly—you’ll get the lows you’ve been missing and the Play units can concentrate on delivering bolder mids and highs.

If, however, you already own a great pair of speakers that you’re driving with a Sonos:Amp or older Sonos amplifier, the Sub may be a nice, but not entirely vital addition to your existing setup.