The Chromecast Audio is a dongle that upgrades existing sound systems to networked, wireless-streaming capability. Happily, the low price and small size of the dongle doesn’t mean it skimps on sound quality—the device features stereo-analog and digital-optical outputs. Furthermore, Google’s audio streamer handles true hi-res audio by supporting PCM streams with up to 24-bit/96 kHz resolution.
A few months ago, I picked up a Chromecast Audio, mostly out of curiosity. It worked just fine, but you could only stream to one device, which was limiting. Then, in December 2015, Google updated the unit and added a group function, which brought multi-room audio to the platform. It wasn’t until I returned from CEDIA 2015 that I added two more of the devices to my home network and experienced the joys of having high-fidelity music playing throughout the house.
From a hardware perspective, there’s hardly anything to the Chromecast Audio. It’s a tiny (2″ diameter), featherweight (1 ounce), disc-shaped plastic device with precisely one button, one USB input, one status LED, and one 3.5 mm output that supports both analog (stereo) and digital-optical (mini-TosLink) connections.
An interesting point about the Chromecast Audio and how it’s positioned in the marketplace is the way it’s sold at Best Buy. When I went to my local store, I found the Chromecast Audios in the section reserved for AVRs and 2-channel receivers—as opposed to the streaming media-player section or the wireless-speaker section with all the Sonos gear.
The Chromecast Audio comes with a short (6″) stereo analog cable that works with the auxiliary 3.5 mm input found on many soundbars and self-powered speakers. If you want to use an RCA adapter or a digital-optical cable, you will have to buy one separately—I bought a couple of Monoprice digital-optical cables from Amazon for $5 each, and they work perfectly.
Wi-Fi is the Chromecast Audio’s sole connectivity option for streaming audio, using 802.11 b/g/n/ac (2.4GHz/5Ghz)—in other words, it almost certainly works with your current router. Notably, the micro-USB connection on the dongle is there strictly to power the device; the Chromecast Audio will not function as a USB DAC.
Unlike some other streaming-audio systems, Chromecast does not employ a proprietary app for accessing streaming services. Instead, this feature is incorporated into the native apps of supported services, including Google Play, Pandora, Spotify, Real, and others.
In addition to using supported services, you can cast audio from the Chrome browser on a Chromebook, PC, or Mac. Furthermore, you can mirror audio that’s playing on your mobile device through Chromecast, which provides a way to stream sound from unsupported services such as Tidal.
Chromecast Audio streams audio directly from the web, and in most cases it does not depend on the device that initiated playback—except when mirroring from a mobile device or casting from a Chrome tab. The advantage of the cloud-based approach to streaming is that playback does not consume any battery power. Furthermore, you can use any connected device that’s cast-enabled to control audio playback. There’s even a “guest” mode that lets visitors join the fun without needing to log into your Wi-Fi network—your friends just need a 4-digit PIN of your choice to connect.
If you are mirroring the audio from your phone or tablet or from a Chrome browser tab on a computer, the audio stream is dependent on that particular device. Chromecast Audio offers quite few streaming options for audio playback, but there is one role it cannot serve—it cannot function as a sound card for your PC or Mac. Simply put, you cannot stream audio directly from your PC’s desktop.
The most outstanding feature of Chromecast Audio is the ability to create groups that contain multiple devices—that’s what makes it a viable alternative to proprietary multi-room wireless audio systems like Sonos. You can create as many groups as you wish, and you can add as many devices to a group as your network will handle. There’s even a setting for adjusting the delay of each device in a group—to counter any latency—and you can trim the volume of the individual devices as well as for the entire group.
Setup was a cinch. Connecting a Chromecast Audio to my Wi-Fi network was easy; after plugging it in, I found it and configured it using the Chromecast app for Android—alternately you can use the iOS app or the Google Cast extension in a Chrome browser. I chose my Wi-Fi network from a list, entered the password, waited for a brief update to finish, and I was in business.
Importantly, there is one crucial setting that needs to be changed in order to get the highest possible fidelity out of the Chromecast Audio. It’s the Full Dynamic Range” option found under Sounds, and by default it is disabled! There’s a note in the menu that states the setting is “for AVRs and Hi-Fi systems.” So, make sure that the first thing you do with your new Chromecast Audio is turn on Full Dynamic Range. I see no harm in doing so no matter what type of speaker it’s used with; Google should have the feature enabled by default.
I connected two of the Chromecast Audios to different full-sized sound systems. One was the Rotel RB-1590 and RC-1590 system featured in this review, which was located on the first floor of my house. The other big rig was a 7.2.4 Atmos system that’s set up on the top floor of my three-story home. For both of those systems, I used the digital optical connection. I also connected a third Chromecast Audio to a desktop system consisting of the ultra-budget Lepai LP-2020+ 20-watt class-T amplifier (which sells for under $30) and a pair of Pioneer Elite SP-EBS73 bookshelf speakers. That system was located on the second floor, and used an analog connection.
I used the Chromecast app to create a group named Whole House that included all three devices. Then, I created a group for each pair of Chromecasts, giving me four groups total to test the system. Each unit can be controlled individually as well.
A wireless-audio system is only as good as its ability to stream reliably. Fortunately, I experienced no performance issues with Chromecast Audio. As I mentioned earlier, I live in a row house, and the router is located on the middle floor of the structure, near the front. The downstairs Chromecast Audio was about 50 feet away, one floor down and two rooms away from the router—and yet even that unit streamed reliably. As a point of reference, I was not able to get a Sonos Play:5 to work without interruption when placed in the same location without using a Sonos Boost, which is a dedicated wireless hub for Sonos systems.
The Chromecast Audio system was responsive to commands such as pausing playback, skipping tracks, and changing albums. I could adjust the volume without noticeable latency, and I appreciated being able to use the physical volume buttons on my phone. Even switching between different streaming services was nearly instantaneous. The only delay I experienced was when I selected a different group—sometimes it would take a few seconds for the system to make the switch.
The sound quality of the Chromecast Audio’s output is worth discussing for a moment. We’re talking about a $35 device here, and yet what I heard was as good as any digital source component I’ve heard. Furthermore, audio fidelity was great regardless of whether I used the digital or analog connection. The Chromecast Audio bolsters the argument that modern DACs are sufficiently flat and transparent as to effectively all sound the same. So it is with the Chromecast Audio—you can even plug a pair of quality headphones directly into the 3.5 mm jack and scrutinize its output for perceptible distortion; you won’t hear any.
Over the course of the past few weeks, I streamed all sorts of music through the three Chromecasts, and used them in various combinations—sometimes I played the same thing in all rooms, other times I streamed different tunes on each one. My greatest concern—that the system would somehow get confused or choke because of bandwidth-related issues—did not come to pass.
Unfortunately, I was not able to measure the frequency response of the analog output from the Chromecast Audio since I can’t stream desktop audio from REW (Room EQ Wizard). Google does not publish frequency response specs for the Chromecast Audio, but if I figure out a way to get that measurement, I’ll post it.
Simply put, I’m blown away by the performance of the Chromecast Audio. It’s the first networked-audio ecosystem that I felt compelled to build upon—once I got a taste of high-fidelity streaming audio, I very quickly learned I couldn’t live without it.
I will grant that Chromecast Audio is not as polished as some of the other networked-audio systems out there—it’s also the new kid on the block—but it succeeds where it counts. Once you have the software installed and name your speakers and groups, streaming superb stereo sound throughout your house, apartment, or condo is as easy as pushing the cast button in a supported app. The sound that comes out is eminently listenable by any standard, and practically qualifies as a miracle for a $35 device.
Rotel RB-1590 amplifier
Rotel RC-1590 preamplifier
KEF R500 speakers
KEF R400b subwoofer
Lepai LP-2020+ amplifier
Pioneer Elite SP-EBS73 bookshelf speakers
Marantz SR7010 AV receiver
Crestron Procise ProAmp 7×250 amplifier
GoldenEar Triton Five tower speakers
GoldenEar SuperSub XXL subwoofers (2)
Linksys EA4500 N900 dual-band router
Xfinity 150 Mbps Internet service