A smart soundbar adds music streaming and voice capabilities to any TV with an HDMI port. These are our favorites.

Ty Pendlebury is a journalism graduate of RMIT Melbourne, and has worked at CNET since 2006. He lives in New York City where he writes about streaming and home audio.

If you're in the market for a fully-featured sound system for your TV, then a smart soundbar brings the prospect of music streaming and a voice assistant into a single unit. Brands to be on the lookout for include Bose, Polk, Sonos , Roku and Yamaha, and prices start at a little over $100.

Before I show you the picks it's worth making a distinction between a smart soundbar and a smart TV . While a smart TV usually means it has onboard streaming apps, a smart soundbar instead means it has an onboard voice assistant -- usually either Google Assistant or Amazon Alexa. The exceptions here are the Roku Streambar and Streambar Pro (previously Smart Soundbar ), which do have streaming apps and an optional always-on assistant.

Be aware: Some of these products are currently on backorder, though the Roku and Polk products are available.

The compact Roku Streambar plugs into your TV's HDMI ARC port and works as both a 4K streamer and a soundbar. We've found the Streambar easy to set up, and it sounds good for the size, particularly with dialogue. To make the soundbar truly smart, the $30 Voice Remote Pro adds an always-on voice assistant which is handy for finding new shows and even the remote itself.

Read our Roku Streambar review.

The Polk React with DTS Virtual Surround Sound is a single soundbar update to one of my favorite smart soundbars, the Polk Command Bar. While it misses the subwoofer you can always buy an add-on one, and rears too. The 3D surround sound technology offers excellent sound quality and the Alexa onboard is responsive. If you can afford it, it's worth spending the extra $80 on the Yamaha YAS-209 for its subwoofer and additional HDMI port.

Read our Polk React review.

The Yamaha YAS-209 offers excellent sound quality in a compact soundbar with Amazon Alexa voice control built-in. The mics work well in loud environments and you can use them to stream music. DTS Virtual:X  surround sound offers a rich effect reminiscent of surround speaker sound, and the smart soundbar comes with an articulate soundbar's wireless subwoofer. Unfortunately, the Yamaha soundbar YAS-209 doesn't use the company's MusicCast system, so it won't sync up with other Yamaha speakers. The YAS-209 is currently out of stock, but the identical Costco version called the ATS-2090 may be available instead.

Read our Yamaha YAS-209 review.

With the addition Dolby Atmos, the Sonos Beam Gen 2 is now the mid-priced smart sound bar to get. It offers a choice of either Alexa or Google voice assistant, and the Sonos ecosystem is one of the best music streaming platforms around. You may be missing out on deep bass without a sub, but this compact speaker makes your movies sound huge with its virtual surround capabilities.

The Sonos Arc is the grown-up version of the Beam and offers a number of upgrades for the extra cash. The first is the use of dedicated, upfiring Dolby Atmos speakers which gives it an edge in movies, and the second is more drivers and a bigger cabinet for better bass performance. Otherwise this is another great Sonos offering with the choice of voice assistants and the best system in music streaming.

Read our Sonos Arc review.

At CNET I test audio equipment from compact soundbars though to surround sound speaker systems, but regardless of the device my methodology is largely the same. I always compare products against one or more reference devices that offer the best performance at a similar price. 

When it comes to soundbars, I want to see how well a system performs with music as well as with movies, as most people will want to do both. I watch from a handful of test scenes from 4K Blu-ray or streamed from a 4K streaming service (Vudu, for example) and evaluate aspects such as bass performance and dialog clarity. I also use a number of test music tracks and evaluate any streaming features such as Bluetooth and Wi-Fi. Systems that can perform well with both types of entertainment that inevitably score the highest.

See my how to buy a soundbar for more of the features and other things you should consider when looking for a new system.

While a smart soundbar is usually used to describe a soundbar with an onboard voice assistant, but it can also mean a soundbar that has video streaming capabilities, such as the Roku Streambar. A smart soundbar is often used both as a streaming device and to control other smart home devices via voice. The two assistants that are commonly included with soundbars are Google Assistant and Amazon Alexa. 

It's worth noting that adding a separate Google Nest mini or Amazon Echo device to an existing, internet-connected soundbar can often give the same capabilities as a smart soundbar. The added advantage is that it doesn't tie up your soundbar when you ask it a question.

As most TVs these days are smart TVs it doesn't really matter if the soundbar is smart or not, the combination should still work great. A smart soundbar will add voice capabilities to any system. The Roku Streambar will also work with an existing smart TV, and you can choose either the TV or the soundbar as your main streaming device.

There are two types of smart soundbar -- one which offers a single voice assistant (usually Amazon Alexa) and one which offers a choice of either Google Assistant or Alexa. The Polk React and the Yamaha YAS-209 are two examples of Alexa-only soundbars, while Bose Smart Soundbars and Sonos products offer both assistants.