AudioQuest Dragonfly Cobalt

Sub Gen3 Wireless Subwoofer Review

Enhance the bass of your Sonos music or home theater system with the new Sonos Sub Gen. 3




  • Huge Bass, Compact Cabinet
  • Place Anywhere
  • Trueplay Tuning

Today’s review is on the new Sonos Sub, a wireless subwoofer that can be used to enhance the deep bass in your Sonos music or home theater system.

Company & Product Overview

When California based Sonos introduced a radical new way to experience music almost 20 years ago no one knew at that time they would grow to become the standard in high-performance wireless sound and speakers. Their simple line of products have appealed to music lovers who want to experience the world of streaming audio with ease of use and great sound.

When Sonos entered the home theater market with soundbars, they once again changed the way people thought about soundbars with their extraordinary sounding products that could also be part of your music system.

Sonos first introduced a wireless subwoofer in 2012. Today’s brand new Sub is the third generation of this great addition for any Sonos system.

Design & Build Quality

The new Sonos Sub is designed to augment the bass of any Sonos speaker or can even be used with your own speakers if you are powering them with the Sonos Amp. You will have a choice of a beautiful gloss black or gloss white finish. The Sub is roughly 15” high by 16” wide and about 6” deep. You will certainly want to bend your knees when you move it around as it weighs 36 pounds.

The relatively thin cabinet design of the Sonos Sub allows you to hide it in many applications or you even have the option of laying it on its side if necessary.

We really like the physical appearance of the Sub with its rounded corners and cut out in the center for the dual bass drivers. Unlike most black box subwoofers, the Sonos Sub looks much more finished and refined to our eyes.

Build quality is like all things Sonos, just top-notch. Sonos is one of those rare companies that actually tests each and every product as it comes off its production line. Before a product makes it into production it goes through a series battery of stress tests as well. This is a big reason Sonos products have our lowest failure rate of anything we sell at Audio Advice.

Features & Technology

The Sub uses two oval, racetrack-shaped drivers that face inward. This force canceling design assures you the cabinet will never rattle even when you crank things up loudly. Sonos powers each subwoofer driver with an individual amplifier designed to bring out the best from the dual speaker design. The new version of the Sonos Sub has much more internal memory and a faster processor that will allow Sonos to send out future performance enhancements through system updates.

One thing that is very important when blending a subwoofer to a system is getting the crossover point set correctly. That is the musical frequency where the bass transitions to the subwoofer and the mids and highs go to the main speakers. Done properly, you can perfectly blend a subwoofer with your speakers, however, if you set the crossover too high or low, the results can be very bad sound.

What is so cool about adding the Sonos sub to an existing Sonos system is that for most cases, when the speakers are all Sonos, the app knows what you are matching up to the subwoofer and the Sonos software knows the rough range for the crossover point. But the real magic happens with Trueplay. This will play about a 3 minute series of test tones and their software will figure out the perfect crossover point and adjust the volume of each speaker.

Trueplay even works if you are using your own speakers with the Sonos Amp and Sub. Should you wish to fine-tune the level of the sub to your own tastes, simply open up the app and you’ll have a volume level adjustment at your fingertips!


We’ve tested the Sub in a variety of setups using the Arc, the new Arc Dolby Atmos soundbar, with a pair of the Sonos Fives, and with many different speakers paired up to a Sonos Amp.

From music to movies, the Sub delivers great bass that is well defined and quite impactful. Sonos claims the Sub can reach down to 25Hz which is pretty amazing for its size, (although we are not sure how many dB down it is at that point). The bass is never boomy and always adds that bottom end fill that makes movies and music more fun.

By taking the bass away from your main speakers, the midrange also opens up which we especially noticed on the Sonos Five and when using other stereo speakers with the Sonos Amp.

Overall Recommendation

Bass is the foundation of music. Our advice is the Sub will improve any Sonos system out there. Add it, run TruePlay, and enjoy music and movies at a level you were not expecting!

  1. Sonos Sub (Gen 3) Wireless Subwoofer Sonos Sub Wireless Subwoofer - Gen. 3


AudioQuest Dragonfly Cobalt Highnotes 3

Huge Bass, Compact Cabinet

Dual driver system delivers awesome deep bass

AudioQuest Dragonfly Cobalt Highnotes 2

Place Anywhere

Software allows you to put it anywhere in the room, even lying flat under a couch

AudioQuest Dragonfly Cobalt High Note 1

Trueplay Tuning

Trueplay fine tunes the Sub to both your room and the speakers you are pairing with it. The acoustic adjustments Trueplay does are similar to what you might get in a very high end home theater receiver, pretty amazing for the price

Recommended Products:

  1. Sonos Five Wireless Speaker System Sonos Five Wireless Speaker

  1. Sonos ARC Soundbar Sonos Arc Dolby Atmos Soundbar

  1. Sonos Amp Sonos Amp


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