You might have a great pair of stereo speakers and you want them to work without creating a big mess of cables, Google has something for you. Chromecast Audio is a WiFi based wireless audio streaming device that can be accessed from any location in the house as long as you are connected to the same WiFi network. It has a couple of cool features that most Bluetooth speakers don’t have and that makes this device worth buying. Instead of going into the construction of the device, we will first see why this device is so great.
Work on WiFi
Big problem with Bluetooth devices being, you can only stream audio to your speakers from a distance of few feet and then it glitches. But if you have a large house and decide to stream something from your bedroom upstairs to the speakers downstairs, that is not going to be a very good experience; although it is unlikely for someone to play music in some other room while sitting somewhere far away. However this brings me to point out a new feature that Chromecast audio brings to the users.
If you have speakers sitting in every room and have a big party going on, you probably would want to have the same music playing across your entire house. All you have to do is connect your Chromecasts to each and every speaker that you want to play music on and finally, using the Chromecast app on your phone, you can sync the same music across all your speakers. Only requirement is, you should have WiFi access across your entire house and all the Chromecasts must be connected to the same network. At this point in time, the firmware with this feature is not out yet, but Google has promised this feature to be sent out via Over the air update before the year ends.
Since, Chromecast audio works on WiFi and probably has much of the WiFi protocol stack implemented on it, it can act as a WiFi Soft AP for your guests to connect to it and stream music of their choice. Of course, you as the owner of the device will need to enable guest mode for them to connect to the Chromecast Audio. It can work on 2.4GHz as well as 5GHz WiFi networks.
Construction and internals
Chromecast Audio is circular, thin device with a matt finish Chrome logo on the front and vinyl style groves that go around the logo almost all the way to the edge. Google provides three colours to choose from, black, lemon yellow and red. There is a 3.5mm audio output jack on the side and a micro USB power port located diametrically opposite to the jack. There is a 3.5mm audio cable provided with the package, but it is just short, although quite perfect in most situations. You also get a nice wall adapter and a detachable USB cable. There is a power/reset button on the Chromecast Audio to turn the device on and off and reset it in case it stops responding.
Once you turn the device on, using the Android Cast app, you can find it, set the password to access your WiFi network and start streaming music to it. Obviously, you will first need to connect it to your speaker or amplifier.
iFixit did a teardown of this device as well as the Chromecast device (used for screen casting) and from that we can see the similarity of parts between the two devices. Both have Marvel media processor and the Marvel Avastar Quad radio solution for WiFi. There is a 2Gb flash memory and 2Gb of SDRAM on the Chromecast Audio.
Apart from that, we can find a bunch of other chips for RF signal amplification, combining and splitting. Chromecast Audio uses two antennas to evenly receive and transmit signals in the spatial domain. There are two planar antennas, longer one for 2.4GHz and a shorter one for 5GHz band.
The Chromecast audio could work on Bluetooth if the firmware was developed to do so, because the Marvel Avastar 88W8887 Quad receiver SoC can also be configured as a Bluetooth communication device along with WiFi, both running at the same time.
On the whole, Chromecast Audio is a nice little device made from plastic parts. Being small in size, it can be hidden quite well and using it is very simple with bare minimum physical inputs.
Having an internal battery would have made Chromecast audio a little thicker in size, but it would have definitely gotten rid of the adapter and the extra cable that needs to be plugged in.
Audio section and performance
The Chromecast audio throws stereo audio that can be channelled directly to a speaker or an amplifier without the need of any digital decoding. To be able to drive a wide variety of speakers in this world, the audio output circuitry has to be quite robust. An iFixit tear down reveals a Texas Instruments DRV632 stereo line driver IC that is capable of driving any stereo speaker with impedance of up to 600 Ohms. The output voltage can be set at 1Vrms or 2Vrms, which is quite standard in such devices. After all, it all depends on the power it can deliver.
DRV632 is quite simple to use, with minimum components required apart from the chip itself. This is especially a good selection considering the compact size of Chromecast. THD response of the chip stands at 0.002% (approximately) throughout the audio band with a little jump in the upper mids. Crosstalk between the channels also remains low between -120dBrA and -100dBrA according to the datasheet.
Chromecast audio performs just as good as the technical data says. According to the most users, audio performance is well balanced across the audio range with no audible distortion.
It is a simple to use the Chromecast app which allows you to either mirror the phone audio to the Chromecast Audio device or you can push an online music stream to it and let it handle all the decoding. Both ways, you can do multi tasking on your phone or tablet without interrupting the stream. The non-audio version of Chromecast also works in a similar manner, only difference being that it has to fetch and decode video streams. This information justifies to have a 2Gb SDRAM on a device that appears to be so simple.
Not all apps can cast
Upon installing and setting up the Chromecast, you will see a “cast” icon whenever you are connected to the device. You may not see this icon on every multimedia app that you currently have. At this point, almost all worthwhile multimedia apps are supported with few exceptional facing some problem with sync issues.
If you happen to cast audio and watch a video on your phone, it does not necessarily mean that both would be in sync. Users have noticed this problem with Netflix app, where the audio would lag by a few milliseconds. It is not very clear where the problem lies, with the Chromecast audio’s firmware or with the Chromecast App. Same problem can be experienced with Comedy Central’s app.
There isn’t a whole lot to complain about apart from occasional blip in the audio whenever an app crashes on your device. iOS users certainly have something to complain about. The itunes app still does not support casting audio or video to Chromecast and nor does Amazon’s video app, no surprises there!
Depending on your needs, the Chromecast Audio can be a very useful device in your home, unlocking many different ways to stream audio across devices in your home. It is not just a regular wireless audio device, it works on WiFi and has the ability to connect to the internet. It definitely does a lot more than Bluetooth speakers. The ability to control it from anywhere in your house without needing to worry about going out of range from the speaker is something that is unique to this device. For $35, Chromecast Audio is a device worth buying; a step into world of network based streaming or rather, the internet of things.