Of course, that design choice was a very deliberate one. The Playbase, which will be available worldwide on April 4th, is meant to live on a media stand with your TV placed on top of it (hence the name). The wide profile means it can accommodate most TVs with screens up to 60 inches, and its thin, unembellished design keeps the Playbase from drawing attention to itself when you sit down to watch a movie.

Speaking of the sort, Sonos' own research shows that 70 percent of TV owners don't mount their sets to the wall. That simple fact means that lots of Playbar owners have set their systems up in a way that isn't aesthetically pleasing or even very functional.

"We have a lot of really energetic fans and supporters out there who are very eager to give us feedback," Sonos creative director for industrial design Dana Krieger told Engadget at a media event in the company's Boston headquarters last month. "If we ask people to show us pictures of their products at home, they're very happy to do it."

Those pictures revealed a fatal flaw in the Playbar: lots of awkward setups with the large speaker perched in front of TV sets on shelves and media stands not designed for it. "That's really what drove us to do this," Krieger said. "We saw the sound experience is really performing for people, but the product aspect ratio and architecture could be a better fit to certain environments."

Tackling the design challenge

Right from the start, the Sonos team imagined the solution as a large, flat speaker that a TV could stand on -- but it took three years to achieve something that met the company's exacting audio standards. "The balance we're always working with is the acoustic experience, the WiFi performance and then the exterior product execution," Krieger said, "and they tend to have different north stars."

From a physical design standpoint, the challenge was to make the Playbase as thin as possible while still enabling the audio quality Sonos wanted to achieve. "Really early on, we identified the thinness of this product as being critical to its success," Krieger said. "So in any of those [prototype] form factors, you'll see that being a consistent element. But what do we do with the rest of the product?" The good news is that while the Playbase is slim, it's also very wide and deep, offering a lot of overall space to work with.

So Sonos went ahead and put a full-on subwoofer in the Playbase, mounting it horizontally instead of vertically. That's an unusual decision, but one that was necessary in order to fit a subwoofer into such a thin space. It also gives the Playbase an advantage over most other soundbars, including even the Sonos Playbar.

But the internal subwoofer led to other problems -- specifically, how to move the air and sound a subwoofer creates out of the speaker without diminishing overall sound quality. To increase the amount of surface area inside the Playbase, Sonos used a curved, S-shaped port that pushed air and sound from the subwoofer out the left side of the speaker. This has the added benefit of moving air over the CPU for cooling purposes.

That idea led to another tricky design challenge. The meticulously patterned holes that wrap around the front and sides of the Playbase were interfering with bass and air output. The pattern, which Sonos also used on the Play:5's grille, worked great on the front, but as it wrapped around the sides, it just wasn't right for the air displacement. "When we tried to apply that treatment around the sides, where the subwoofer is pushing all its air, there was a really undesirable impact on the sound," Krieger said.

So the engineers gradually increased the hole size as the grille wraps around from the front to the sides, a subtle change that's important in several ways. The bigger holes are necessary for audio performance, but they'd be a visual distraction on the front of the speaker. The gradual size change allowed Sonos to keep the look of the front face as minimal as possible without compromising audio quality.

"It's all centered around the user experience of becoming invisible," Krieger said. "The kinds of details we spend a lot of time talking about we expect will either never be noticed by owners, or maybe it's in the third or fourth year of ownership. You see something [on the speaker] from a different angle, and we really want those moments to make you love the brand more."

Getting the right sound

Industrial design challenges weren't the only tricky part about building the Playbase. Sonos wanted the speaker to work equally well for both movies and music, a rather unusual goal. Giles Martin, a Grammy-winning producer who works as the "sound experience leader" at Sonos, simply said that experience was "really, really hard." The challenge was getting everything to sound natural and balanced and keep from compromising that natural sound, regardless of whether it was from an album or from a film.

"The reason why I liked Sonos speakers to begin with, before I was even involved, is there was a directness to the speakers," Martin said. "They just sounded fully natural. The irony is, the more unnatural the shape, it's harder to [make it sound] natural. You need that wide spaciousness, because that's what gives us immersiveness, but a voice has to sound like a voice."

Keeping dialogue front and center ended up being one of the most important and difficult parts of getting the Playbase to work. That process of getting the speaker finely tuned for movies was new territory for Martin, who joined the company after the Playbar had been released, making this his first real foray into creating a home theater product.

"The world of film is much more complex [than music], because it's a multi-channel system," Martin explained. "You have surrounds -- what do you do with those in a three-channel system? You have dialogue, effects and music, and the balance and interplay between those elements ... a home theater speaker can really damage or enhance."

As with the Play:5, though, Martin said that the guiding principle was making everything sound the way the creators intended. In the case of movies, that meant bringing the Playbase around to people responsible for the final movie mixes. "For me, the key person is the person who had the last say, and that's usually the mixer," he said.

The Playbase's odd form factor, of course, presented a challenge for getting the right audio clarity throughout the design process. "You don't want that speaker to sound like it looks," Martin said, owning up to the fact that flat, wide speakers are at odds with good audio performance. "But you do want it to look like it looks."

In use

Setting up the Playbase is a simple affair: There's only one connection cable, an optical audio input. Once it's hooked up to a TV, you can complete setup using the iOS or Android app. There are a few different ways to set up the speaker, depending on the equipment you have. You can run it as a single speaker, with 5.1 surround sound mixed down to work on the three-channel device. You can also wirelessly connect it to a pair of Sonos' smaller Play:1 speakers and use them for rear surround output. Naturally, it works with the existing wireless Sonos Sub as well, letting you build a full wireless 5.1 setup.

I got to hear the Playbase in all of these different configurations, and it impressed across the board. But what was most surprising was that it worked equally well as a music speaker as it did when playing movies and TV. That's hardly a scientific impression, but when playing music, the Playbase sounded nearly as good as the flagship Play:5. Stereo separation was impressive, considering the limitations that come with using a single enclosure, while vocals were up front, clear and present. The level of detail the speaker pulled out of music made listening a delightful experience. As I wrote when trying the Play:5 for the first time, I heard aspects of familiar songs that I had never noticed before.

As for movies, the Playbase is a clear upgrade over built-in TV speakers, making the scenes I watched from films like Wall-E, The Jungle Book and The Revenant feel more impactful. Oddly, stereo separation when watching films wasn't quite as strong as it was when listening to music, but I'm splitting hairs here. You'll get better audio with dedicated, individual speakers, though that enhanced quality will take a lot more work and money than many (myself included) are willing to put into their home theater. The notion of a single-speaker solution that works well for both movies and music is quite appealing, even though its $699 price gave me pause. Again, as with the Play:5, you get a lot for your money -- but it's also simply a lot of cash for those who are used to playing audio through a TV.

We'll need to put the Playbase through a full review before passing judgement, but at first listen, it seems like the quintessential Sonos product: a good mix of features, sound quality and industrial design in a somewhat unexpected package that's just too expensive to appeal to a mass audience. It's not so much that it's expensive for what it is; it's just that most people aren't spending $699 on any home audio product.

But despite working in a rather niche space, Sonos appears to be hanging in there, after layoffs and some management shuffles made it feel as if the company was on some uneven footing. It's no surprise that the company is putting on a positive face as it launches its first new product in 18 months, but Sonos does have a powerful "gateway drug" product in the $199 Play:1 speaker, something that gets lots of customers hooked and interested in buying more speakers.

While the Playbase has a high price, the limited time I spent with it convinced me that Sonos is solving a real problem with this hardware. For one reason or another, I've never mounted my TV, and so the Playbase would fit right into my current setup. Adding only one power cord and one optical audio cord to my media stand, which is already overrun with far too many cables, is doable. And it would be a huge upgrade over what I'm using now. I gave up on having true 5.1 audio years ago, sacrificing quality for convenience. But now I'm dreaming about having a wireless surround sound system, with the Playbase at the center. It will just take me a while to save up the cash to make that dream a reality.