Bose Smart Soundbar vs Polk Audio Signa S4: Which mid-range soundbar is for you?

It's no secret that the best soundbars are expensive. I've tested the $1,699 JBL Bar 1300X, a surround sound system that made me foam at the mouth — but there's no way I'd ever be able to afford that.

Mid-range soundbars usually have some sacrifices: poor Dolby Atmos performance, lackluster bass, no smart features... just to name a few. However, as someone whose job is literally to test soundbars, I've discovered a few hidden gems.

Of course the Bose Smart Soundbar and the Polk Audio Signa S4 can't go head-to-head with giants like the Sonos Arc Ultra or the Marshall Heston 120, but for $549-$449, they're pretty impressive. But which is the ultimate winner? There can only be one...

At a glance

Think of this as a TLDR: the Bose Smart Soundbar is a better everyday product with smart features, but the Polk Audio Signa S4 is a better cinema product.

Bose Smart Soundbar vs Polk Audio Signa S4: Specs

Bose Smart Soundbar vs Polk Audio Signa S4: Design

Despite both soundbars being firmly in the midrange of both cost and performance, there are a few key differences between their designs.

The Bose Smart Soundbar is much smaller than the Polk Audio Signa S4. The Bose is 27 inches long compared to the Polk's 41 inches. Even so, each soundbar has the same number of center and upfiring speakers (three and two, respectively), and has comparable sound quality.

However, size isn't the primary point of comparison here. The main difference lies within the Signa S4's subwoofer. Unlike the Smart Soundbar, which can be used with Bose's Bass Module 700 ($899)(... yes, really...), the Signa S4 is a soundbar + subwoofer combo. For just $449.

I'll discuss the sound more in the 'Sound quality' section below, but let's just say that the Signa S4 is pulling ahead right now, purely because it has a subwoofer.

With the main differences out of the way, the Bose and the Polk Audio are comparable in most other design aspects. True, neither of them are breaking any beauty boundaries (that award goes to the Marshall Heston 120), but neither are markedly ugly, either.

The Signa S4 has a gray fabric mesh covering, which might look a little dated if you've got an ultra-modern home, but I don't see it looking out of place in a home cinema setup. Conversely, the Bose Smart Soundbar has a plastic body with a large 'Bose' logo in the center, which is better if you like the look of a branded soundbar, or you perhaps want to show off to your less-techie friends who assume Bose is the be-all and end-all of audio quality.

My final point of comparison is the remote controller. The Polk Audio remote is much sturdier than the Bose, with more buttons and a larger surface area. The Bose remote is quite flimsy, but, then again, the Bose can be controlled via the Bose app, which I'll discuss more just below.

The winner? There isn't one. The Polk Audio Signa S4 could take the crown because of its subwoofer and superior remote.

But the Bose Smart Soundbar looks better and is smaller, therefore more versatile.

The result? A draw.

Bose Smart Soundbar vs Polk Audio Signa S4: Features

In terms of features, there are a few key differences between the Polk Audio Signa S4 and the Bose Smart Soundbar.

First, though, let's get this out of the way: the Smart Soundbar and the Signa S4 have different use cases and, therefore, have different features. The clue's in the name: the Bose is, literally, a smart soundbar. It's going to have smart features.

Let's chat about them separately: first, I'll discuss sound quality-related features, then I'll discuss smart home features. Or, in the Signa S4's case, the lack thereof.

The Bose Smart Soundbar has an array of sound features: Dialogue enhancement, channel volume adjustment, and 'Bose TrueSpace' (for Atmos decoding). The AI dialogue enhancement is one of the best features on this soundbar: I never, ever struggle to hear dialogue. Even during loud action scenes, I am always able to understand dialogue.

You can also adjust each channel speaker independently, so you can increase the volume of the 'Center channel,' 'Height channel,' 'Bass,' and 'Treble' at will. Obviously, I upped the bass to the max, as the subwoofer is a separate purchase, and the soundbar needs all the help it can get bass-wise.

Finally, I'll discuss 'Bose TrueSpace'. This technology is supposed to upmix audio signals into an immersive, surround-sound experience. While obviously this is not Dolby Atmos or DTS Virtual:X, it tries to make everything you watch sound like it could be.

TrueSpace is really frustrating because it could be so good. It's not frustrating because it's bad, or because it's excellent, but a weird amalgamation of the two. Sometimes TrueSpace is awesome and makes me feel like I'm actually underwater during swimming scenes. Other times, I'm trapped on the outside, like I'm hammering on the door of Dolby Atmos and it won't let me in.

If this feature were more consistent, I'd be shouting about it from the rooftops. However, as it stands, it's merely good — not great.

Alright, let's talk about the Polk Audio Signa S4's sound features now. Like the Smart Soundbar, the Signa S4 has the following: Voice adjust (for dialogue), Movie mode, and Night mode. Unfortunately, you can't adjust the volume of each speaker, unlike the Bose, but these sound modes are still great.

Movie mode is the only one you really need if you're into blockbuster films. This mode effectively increases the bass, which makes the subwoofer rumble. Night mode does the opposite — reduces bass so you can listen while neighbors or roommates are asleep — and Voice adjust is ideal if you struggle to hear dialogue.

While the Signa S4 doesn't have any DSPs intended to upmix non-Atmos into Atmos, if you've got an Atmos-encoded movie, the surround sound will be impressive. When I was testing the Siga S4, I watched 'The Wild Robot', and the immersive sound effects made me feel like I was actually in the scene.

However, if your content is not Atmos-encoded, then you'll get no upmixed surround sound.

Right, now let's discuss other features. While Bose and Polk Audio stuff their soundbars with similar sound-related features, only one of these soundbars has any smart features, and it's easy to guess which one.

The Bose Smart Soundbar has a huge variety of smart home features. You can link it directly with your Alexa; it comes with AirPlay and Google Cast, so you can play music directly from your streaming app like Qobuz or Spotify, and you can control it completely from the Bose app.

I find myself using the Bose Smart Soundbar every day to listen to music while I'm cooking or pottering about the house. Thanks to the seamless AirPlay integration, I can play music directly from my phone, without having to connect to Bluetooth or connect any wires. If I wanted to play music on the Signa S4, I'd first have to turn on Bluetooth (annoying) and then connect to my phone (annoying), and then play music (annoying).

The Bose Smart Soundbar eradicates that frustrating system, and, as a result, the Bose Smart Soundbar wins in the Features category.

Bose Smart Soundbar vs Polk Audio Signa S4: Sound quality

Now onto the most important section. Everything I've said so far has been leading up to this very moment. I feel like a scheming adviser in a Medieval court. Imagine me rubbing my hands together with glee, smiling like I've heard a joke only I can understand.

First, I'll go over the fact that the Polk Audio Signa S4 has a subwoofer and the Bose Smart Soundbar doesn't. The existence of the subwoofer makes this a very easy assertion: the Polk Audio Signa S4 has much, much better bass than the Bose Smart Soundbar.

The subwoofer itself has one large woofer on the base, so it'll shake your floors. When I was watching 'Top Gun: Maverick' on the Signa S4 in the office, my colleagues who (unfortunately) work on the floor below our testing room complained that it was too loud.

Hey, if floorboard-trembling bass is what you're after, then the Signa S4 will make you happy.

Unfortunately, that brings me onto the Bose Smart Soundbar's subwoofer... well, lack of subwoofer. As I mentioned briefly above, if you want a subwoofer with your Smart Soundbar, it's going to cost you almost $1,000. Oh, I wish I were joking.

Even though the Smart Soundbar's bass performance is alright considering it's just a soundbar, it can't compare. There's no way you can listen to the Signa S4 and the Smart Soundbar and hear the same level of bass.

Although bass is important, it doesn't eclipse every other aspect of audio. There's also the very integral aspect of sound separation. This is basically: Can you hear different sound effects clearly? Is there enough dynamic difference? How does the soundbar deal with sounds across the frequency range?

The Bose Smart Soundbar has amazing sound separation. When I was watching 'Top Gun: Maverick', I could hear all elements of the scene, from the diegetic rope-whooshing and metal-clinking to the non-diegetic 'Danger Zone'.

I could also hear every element in 'Alien: Romulus', but some of the dialogue was a little muffled without the AI dialogue mode switched on. I use the Bose Smart Soundbar every day at home, and it just sounds awesome. It elevates everything I watch, whether that's brainrot YouTube videos or Bong Joon Ho movies.

The Polk Audio Signa S4 excels in different ways. The bass in 'Danger Zone' sounded fantastically groovy, and the roaring of Maverick's jet in 'Top Gun' was earth-shaking.

No, the diegetic sound effects weren't as pronounced as on the Bose Smart Soundbar, but this is a worthy sacrifice if you are a bass lover. I wish the audio separation on the Signa S4 was better, but for a $449 soundbar + subwoofer combo, the performance is really impressive.

The winner of the sound quality section is a hard one. The Signa S4 is better for bass, purely because it has a subwoofer, but the Bose Smart Soundbar is better for dialogue and sound separation.

Oof, I'm going to pick the Polk Audio Signa S4 due to its subwoofer, but if you primarily want a dialogue or music soundbar, then the Bose Smart Soundbar would be your winner.

Bose Smart Soundbar vs Polk Audio Signa S4: Verdict

I'm surprised writing this, but the overall winner is the Polk Audio Signa S4. At just $449, it's $100 cheaper than the Bose Smart Soundbar — and you get a subwoofer out of it, too.

That's not to say the Signa S4 is for everyone. I personally use my Bose Smart Soundbar at home. Yep, I said the Signa S4 is better overall, but I use the Bose Smart Soundbar. Why is that? The Polk Audio Signa S4 is simply too big. My living room and TV stand don't have enough space to house a 47-inch soundbar, which is why both soundbars won in the 'Design' section. If, like me, your home is on the smaller side, you might be better suited to the Bose Smart Soundbar.

However, if you've got a larger home with a decently big TV, the Polk Audio Signa S4 will surprise you as much as it did me. The sound is rich, room-filling, and immersive, and the wireless subwoofer is remarkably loud. I have no doubts that the Polk Audio Signa S4 will treat you well.

Follow Tom's Guide on Google News and add us as a preferred source to get our up-to-date news, analysis, and reviews in your feeds. Make sure to click the Follow button!

More from Tom's Guide

• This has just become my new favorite speaker — and it's a game changer for home audio enthusiasts
• My favorite earbuds for movie nights are the AirPods — here's why
• I toured Apple's secret audio lab to see how it built and perfected the AirPods Pro 3