September 2016

Thanks largely to Google’s Cast system, Wi-Fi speakers are rapidly replacing Bluetooth models. Wi-Fi units use your wireless network to transmit sound, and since they’re not subject to the data-transfer limitations of Bluetooth transmission, they have the capability to provide better performance. The Grace Digital CastDock X2 is rated to handle music files up to 24-bit/192kHz resolution.

Grace Digital CastDock X2

The Grace Digital X2, like other Wi-Fi speakers, depends on the hockey-puck-sized Google Chromecast unit to “cast,” i.e., transmit the sound to a speaker. You can connect it to any speaker that has RCA, 3.5mm, or optical connectors, but Grace Digital has taken this marriage a step further by creating a recessed spot in the speaker where the Google Chromecast unit can be installed. A neatly designed cover then hides it. Grace Digital has also made it easier to plug in the Chromecast by offering it as a package with the X2. The speaker alone sells for $149.99 USD, but you can purchase a package that contains the speaker and the Chromecast device for $179.99. The Google Chromecast by itself usually sells for $35, so you save a little with the combo. You can also find prices online at Amazon and Best Buy, to mention two, that will bring the cost of the speaker down to $99.99. Please note that the X2 is compatible only with the Google Chromecast Audio version of the device.

The X2 proved to be a nifty little speaker with one big potential drawback, which isn’t Grace Digital’s fault. It is incompatible with iTunes, Amazon, and SiriusXM apps. You can’t cast those, but there is a slightly satisfactory workaround, since you can use the 3.5mm input jack and tether your device to the X2. But you can’t leave it plugged in -- you must disconnect for the Chromecast to work again.

In the box

The attractive full-color box contains the X2 speaker, an AC power supply and cord, and a brief user guide. No 3.5mm cable is supplied, which seems odd, since it would have cost little to throw one in and allow a buyer to use iTunes and Amazon. And the Chromecast is not supplied unless you’ve bought it as part of a deal from Grace or another supplier.

The sturdy speaker weighs 2 pounds, 12 ounces, and is 4 3/8” square by 7 3/4” high. Its top and bottom are black with a gray grille in the middle that wraps around the entire unit. The sides are free of controls or switches. The front has an LED light/mute button at the bottom that glows blue for standby, solid green for play, and flashing green for mute. The back has a power cord jack, a 3.5mm jack, and a switch that allows you to hear the left channel, the right channel, or a monaural left plus right signal. So yes, with two X2s you can play stereo by setting one speaker for left channel and the other for right. You can, by the way, add other speakers in other locations throughout your house, but you’ll need a Chromecast receiving puck for each one. The back also has a bass port and a screw socket connector for wall mounting.

Grace Digital CastDock X2

The top of the X2 contains a recessed area that fits the Chromecast like a glove, as well as power and digital cables that are permanently attached. You plug these into the Chromecast, drop the Chromecast into the recess, slip on the plastic cover, and you’re ready to go.

The X2 boasts a 50W class-D amplifier, has a listed frequency response of 60Hz to 20kHz, a two-way speaker system with tweeter and midrange-woofer, and supports hundreds of apps, including Spotify, Pandora, iHeartRadio, Google Play, TuneIn, Slacker, and Deezer. It does not support Amazon or Apple iTunes. As mentioned earlier, you have to use the 3.5mm jack and a 3.5mm cable. You cannot access your music library of files, as the Chromecast will cast only streaming audio.

The Chromecast comes with a very short (6”) 3.5mm connecting jumper cord and a USB-to-USB-Micro cord with an AC adapter. You will need these only if you’re connecting a speaker other than the X2 to Chromecast.


After installing the Chromecast, I had to plug in the power supply. Yes, the X2 can operate wireless as far as connecting devices go, but it must have an AC plugin for powering that formidable internal amplifier. Once this is done, you need to set the channel switch on the back. It came with the switch in the A + B mono setting, which was fine, as Grace sent only one unit for review. Then I had to download the Google Cast app to my IPod Touch, and the X2 popped up -- actually, the setup on this unit is way beyond simple.

There are hundreds of apps available, and I could load them right from the Google Cast app. Many of them cost money, but most have a free trial period so you can audition before buying. Once I had my apps installed, the Google Cast app gave me a list of the ones that could be cast, in my case Spotify, iHeartRadio, and Google Play. I would select one and tap the casting icon, which turned the speaker on, and I was ready to hear whatever I chose that the app offered. The speaker is always on standby, and casting turns it on. Failure to stream music after a certain time puts it back into standby mode.

Grace Digital CastDock X2

That brings up one of my only complaints. That blue LED for standby is very bright, and there’s no way to make it dimmer. Only patching over with black electrical tape will make it go away. Then it’s not serving its purpose. Also you can only mute by pressing the button, though you can do the same thing on your device by using the pause control.

The range was much better than Bluetooth; in short, wherever my Wi-Fi network was operating, which is generally my whole house, I had a connection.


The X2 is a pretty amazing little speaker that sounds much larger than it is. It won’t replace a subwoofer-based setup, but it has low-enough bass that will serve most music genres well. The midrange was smooth -- focused yet fairly transparent -- and the highs were silky, just short of having an annoying paunchiness. I found the sound a bit congested at higher volumes, which made it tiring on long listens, but I imagine that two X2s for stereo would solve that problem nicely. In fact, I could prove this to myself by flipping the switch and playing my single speaker as left or right.

I did a little listening with the cable connected to my iPod Touch, confirming that Duran Duran’s “Bedroom Toys” (Astronaut, 16-bit/44.1kHz ALAC, Epic) had plenty of instrumental and percussive bite with pointed and mellow vocals. Likewise, John Williams’s Olympic Fanfare (Encore, 16/44.1 ALAC, Philips), a very apropos pick since the Rio games are starting as I’m writing this, had very clean percussion (especially the snare drum) and resounding brass, though the bottom organ pedal tones were barely audible. Still, the bottom held pretty well with the string basses and tuba.

Grace Digital CastDock X2

These works and a few others gave me a reference point and proved that the X2 is a serious contender at reproducing music. I then turned to the apps, for they, after all, are what this speaker was mainly designed for.

Kane Brown’s “There Goes My Everything” (Chapter 1, 320kbps MP3, RCA/Google Play) had super defined vocals, which delineated the exact character of the country singer’s voice in spades. The drum set was crisp and the bass was solid. Dolly Parton’s sweet soprano rang true on the title track from Coat of Many Colors (320kbps MP3, RCA Nashville/Google Play) with an exceptionally well defined banjo and plucked acoustic bass accompaniment, with a softly tapped drum providing just the right amount of spice. Who I Am by Nick Jonas & the Administration (256kbps MP3, Hollywood/iHeartRadio) had crisp and clean vocals and good instrumental support, though the electric bass sounded a little underwhelming.

Casting produced volume levels just slightly louder than the 3.5mm cable.

In sum

With the X2, Grace Digital has produced a serious threat to Sonos at a fraction of the cost. You can play music and radio from a group of apps that seems to be growing every day. The X2 attractively docks the Google Chromecast Audio so that all wires except the power cord are hidden. It sounds good, is reasonably priced, and sets up easily. To avoid audio congestion when listening at louder volumes, however, I’d recommend buying two for stereo. It’s something of a bummer that Amazon Prime and iTunes are incompatible, but honestly, there are so many apps that are compatible that you’ll never be able to hear them all. If Apple and Google ever end their feud, the Google Chromecast could be easily updated. So this is a speaker that won’t just give you pleasure today; it can be ready for tomorrow’s apps as well.

. . . Rad Bennett

Associated Equipment

  • Sources -- Astell&Kern AK Jr and Apple iPod Touch (generation five) portable music players

Grace Digital CastDock X2 Wi-Fi Speaker
Price: $149.99 USD
Warranty: One year, limited.

Grace Digital Inc.
10531 4S Commons Drive, Suite 430
San Diego, CA 92127
Phone: (866) 446-0961
Fax: (858) 408-3336