In a perfect world, playing music throughout the house wouldn't require you to navigate a web of competing protocols like AirPlay, Chromecast, and Alexa. Instead, all of your speakers would just play nicely together, no matter who made them.

The reality, of course, is that multi-room audio has become a turf war, with tech giants like Apple, Google, and Amazon fighting for the exclusive right to play music in your home. If you want your speakers to play in sync throughout the home, the easiest thing to do is pick a side.

I don't want to sound too grumpy about this. In many ways, setting up multi-room audio is simpler and cheaper than it used to be. Instead of spending a thousand dollars or more on a Sonos system, you can buy a handful of Google Home or Amazon Echo speakers for a couple hundred bucks or less. Still, each multi-room system has its strengths and weaknesses, which you ought to be aware of before sinking any money into them.

With both Amazon and Google discounting their respective smart speakers this week, I thought it'd be a good time to walk through your multi-room audio options as they stand right now:

Chromecast is the protocol that Google uses to stream audio onto TVs and speakers throughout the house. It's used by Google's own Home speakers and (as of last week) Chromecast TV devices. Some third-party speakers and televisions, including most Vizio products, also have Chromecast built-in, and other speakers can hook into Google's system using Chromecast Audio, provided they have a 3.5mm headphone jack.

With Chromecast, you use the Google Home app (for iOS or Android) to set up speaker groups, such as an upstairs group, a downstairs group, and an "all speakers" group. You would then use Chromecast-compatible apps (such as Spotify, Google Play Music, Pandora, and Amazon Music) to send audio to those groups. You can also play music with voice commands through a Google Home speaker or other Google Assistant device, but you don't have to. In fact, only a subset of Chromecast-compatible music services work with Google Assistant voice commands.

Overall, Chromecast is the most flexible whole-home audio system available today. The cost of entry is cheap (even Google's $50 Home Mini speakers support it), it works with a broad range of music services, and you have the option to use either your phone or voice commands to start playing music. On the downside, Chromecast doesn't work with Apple Music, and it lacks the ability to add a subwoofer or secondary stereo speaker in a single room.

Amazon Alexa also supports multi-room audio. If you have multiple Echo speakers, you can create speaker groups in the "Smart Home" section of the Alexa app or website. This also works with some third-party Alexa speakers, and you can connect other speakers to Alexa using an Echo Dot (via 3.5mm cable) or Echo Input (via 3.5mm cable or Bluetooth), but Fire TV devices don't support multi-room audio yet. Amazon even lets you add extra bass with an Echo Sub or turn a couple of Echo speakers into a stereo pair.

After setting this up, you'd then ask Alexa to play music from supported services (such as Amazon Music, Spotify, or Pandora) on one of your speaker groups. You can also launch music from your phone through Amazon Music, but not through other services.

Like Chromecast, Alexa's multi-room audio is relatively cheap, and the idea of modular subwoofer and stereo speakers is pretty neat. Still, Amazon's system doesn't support as many music services overall (and again, no Apple Music), and now that Amazon Music doesn't support uploading your own songs, there's no easy way to play a personal music collection on Echo speakers throughout the home. (By comparison, Google Play Music lets you upload 50,000 songs for free.)

AirPlay 2 is Apple's system for multi-room audio. It works on Apple's HomePod smart speaker, Apple TV streaming device, and a small number of third-party speakers. You can assign speakers to rooms using the Home app for iOS or Mac, then hit the AirPlay icon (either in Control Center or the music playback menu) to connect your iOS device or Mac to those speakers. You can also use Siri voice commands to launch Apple Music on multiple speakers throughout the house.

The downsides to Apple's system are cost and inflexibility. The cheapest AirPlay 2 speaker (Sonos' One) costs $199, four times the price of a Google Home Mini or Echo Dot, and the only speaker that can launch music with hands-free voice commands is Apple's $350 HomePod. Also, Siri can't launch music from third-party services like Spotify or Pandora. Still, this is the only system that works with Apple Music. And the HomePod, while pricey, offers excellent audio quality for the money. You can even use two of them to create a stereo pair.

After reading all this, you might be wondering if there's any way to get the best of all worlds. The answer is "kind of, maybe," as we're now starting to see some speakers work with more than one system.

The most notable example is Sonos, which supports Alexa voice commands and AirPlay 2 on its Sonos One speaker and Sonos Beam soundbar. The company is also hoping to support Google Assistant (and, presumably, Chromecast) next year. If Sonos can pull that off, it would be the first company to support all three tech giants' multi-room audio systems.

There's some irony for you: Once a keeper of walled gardens, Sonos could be the one to show us the way out.

Got questions on multi-room audio or smart speakers in general? Send me an email or chat with me in real-time on Friday, November 30 at 3 p.m. Eastern.
 

Speaking of interoperability, if you have an iPhone or iPad running iOS 12, you can now ask Siri to connect you with Google Assistant instead. This can be useful for getting directions in Google Maps instead of Apple Maps, playing media (including multi-room audio!) on nearby Chromecasts or Google Home speakers, triggering Assistant’s smart home routines, or broadcasting one-way messages to other Google Assistant devices.

To set this up, make sure you’ve got the latest version of the Google Assistant app, then look for the "Add to Siri" button inside the app. You’ll then be able to record a custom phrase that will launch Google Assistant after you’ve activated Siri. (If your phrase is "Hey Google," for instance, you could say "Hey Siri, Hey Google," or just say "Hey Google" after pressing the Siri button.)

All of this works because of an iOS 12 feature called Shortcuts, which lets you set up automation rules to get things done faster. I recently wrote a deep dive into this feature for Fast Company, and will be sure to share it here once it’s published.
 

Spotify for Apple Watch: Spotify now offers a proper Apple Watch app, letting you select from recent playlists, mark songs as favorites, and send audio to other devices such as smart speakers and laptops. As with other music sources, you can control volume and playback through the Apple Watch as well.

The only thing missing is a way to use Spotify on the Apple Watch without a nearby iPhone. Spotify says it’s working on offline music playback, but hasn’t given a timeframe, and there’s no word on support for direct playback over cellular connections for Apple Watch LTE models.

More screen time tools: Perhaps the weirdest trend in tech right now is companies curtailing your use of their products. Apple introduced Screen Time in iOS 12, providing insights into your device usage and letting you set time limits. Google has been testing a similar feature, called Digital Wellbeing, and now it's available on all phones running Android 9. Facebook has also started rolling out screen time insights, both on Instagram and Facebook proper.

In my experience, none of these features work as well as they could at cutting you off. With Screen Time, dismissing or delaying your time limits is far too easy, with options that appear immediately after you open a restricted app. Adding time in Digital Wellbeing requires a trip to Android's settings menu, which is better, but you can't adjust limits temporarily or during scheduled periods. Facebook doesn't stop you from using its apps at all, and instead just sends a notification saying you're over the limit. I don't want to be cynical and say these companies aren't really invested in the screen addiction issue, but we'll learn a lot based on how much these features improve over time.

Alexa's new smart home button: When Amazon first announced Echo Buttons last year, the company pitched them as a way to interact with trivia games and other diversions. Now, you can use them to control smart home devices as well.

To set this up, you must use the Alexa app to create a "Routine," which associates multiple actions with a single trigger. Select "Echo Button" as the trigger, then add the things you want to happen when the button gets pushed. This could be helpful for turning on a bunch of lights when you walk through the door, or locking down the house and turning off the lights from your bedroom--especially if there isn't already an Echo speaker or other Alexa device within earshot.
 

It’s Cyber Monday, and I’ve rounded up a bunch of noteworthy deals on laptops, desktop PCs, monitors, and more over at PCWorld.

But my favorite Cyber Monday deal of all might be this $7 two-pack of 6-foot USB extension cables, which regularly sell for $10 on Amazon. I have a couple of these for when I want to charge my Xbox controller while playing, and I can think of at least a couple other situations where a longer USB cable would be nice to have. Go ahead, treat yourself to the gift of not stretching your charging cables and accidentally pulling the plug out of the wall.