With voice control, app control, streaming, external inputs and built-in power, the race is on to provide the easiest just-add-speakers plug-and-play zone of multiroom music.

The concept isn’t, of course, new — indeed one of the very first releases from Sonos back in 2006 was a smart zone amplifier designed as a just-add-speakers solution. Every wireless multiroom ecosystem launched since then has had its own version of this easiest of system solutions, the smart amplifier.

The three reviews that follow rise in price order from Amazon’s new smart amplifier to the latest version of the Sonos zone player, and on up to Bluesound’s ‘2i’ edition of its Powernode smart amp, which retails at three times the price of Amazon’s product.

Each of these units connects to your network and the internet to play streaming music. They have internal amplification to drive any pair of speakers. They have additional inputs on the back so you can add other sources, or plug your TV in to enjoy superior sound for TV and movies.

But times are changing, and the three units here all do things differently. One area of change is voice control — everyone wants to offer it, but how well does it work? And which side of the Alexa/Google voice divide does each manufacturer choose — or is it possible to offer both, and Apple’s Siri assistant as well?

All three of the smart amplifiers in this group can be addressed via Alexa. While it’s the obvious choice for Amazon’s own product, Alexa also has the advantage of allowing special skill sets to be downloaded for specific equipment (although Google is now fighting back with ‘Actions on Google’).

So when IHS Markit reported on the rise of voice assistants at IFA’s recent Global Press Conference, they showed us these two charts (below) from data relating to 2018.

The first shows the ‘reach’ of the main voice assistants (Bixby is Samsung’s version), and Google Assistant is very much in the lead in terms of accessible devices in the global market, with Alexa far behind in terms of numbers.

But when IHS started asking people about how often and when they use voice assistants, rather than merely counting devices, the story was different — Google still leads, but Alexa is closer behind. IHS’s conclusion was that consumers crave interoperability, and currently only Alexa is meeting this need.

Apple’s Siri gets a surprisingly good score both ways, and the rise of AirPlay 2 should cement that position. Two of the three smart amps here allow Siri voice control when streaming via AirPlay 2.

Another differentiator comes in the apps that are inevitably used to select and control your choice of music. Some apps are better than others, and some platforms offer a wider choice of online services, and differing support for your own music, both in how they access your files and which types of files they are able to play.

With all this to check up on, it might be easy to forget the most important parameter of all — the quality of their amplification. After all, it’s not much use accessing all the world’s music if the box then makes it sound flat and boring. In theory, all an amplifier has to do is take the input signal and make it bigger. But how much bigger? And how cleanly do the different amplifiers achieve this?

That’s why we gathered all three together in our listening room, and compared them for quality as well as facility, simplicity, and accessibility.

(And for another solution, see the VAIL Amp review here)...

Click to read those three reviews in full: