I tried the Sonos Arc Ultra and Sub 4, and here's why they are the peak of acoustic engineering

Indian Express

3 days ago

I still remember visiting one of my dad's friends when I was a kid. He had a big bungalow, and I was awestruck by his high-end, elaborate home theater setup. This was in the late '90s. Back then, setups like that were everywhere, even in high-street retail shops in Delhi.
Cut to 2025: neither do we have big bungalows anymore, nor do we see home theater systems that require massive space. Today, with compact apartments and space being a luxury in metro cities, Sonos' Arc Ultra soundbar and Sub 4 seem like the ideal surround sound system for anyone looking to recreate a home theater experience in a modern living space.
The Arc Ultra is Sonos' flagship soundbar and serves as a complete audio setup on its own. While the Sub 4 subwoofer is technically optional, the two work together to deliver a truly immersive home theater experience. I had the chance to review both over the course of a few weeks and here's what I found.
What: Sonos Arc Ultra and Sub 4| Price: Rs 99,999 and Rs 84,999
I always tell my readers to visualise how speakers and soundbars will look and feel in their own homes, even while experiencing them at a store. After all, the demo units you see in stores are placed in controlled environments, which makes a big difference. The Arc Ultra carries Sonos' signature design language through and through. At first glance, it's almost indistinguishable from the original Arc I reviewed last year.
The only notable differences are its larger size and the rectangular rear section that houses the ports. Compared to the original, the Arc Ultra is noticeably wider and heavier. That said, the soundbar is beautiful to look at…very minimalist, yet premium, much like an Apple product. You can place it on a TV stand or mount it on a wall, but since I had a reasonably large space, I preferred to keep it on a TV stand.
Like all Sonos speakers, the Arc Ultra comes in classic black or white. It features a solid, premium build, with a grille on the front and top that covers a total of 14 drivers, including seven tweeters, six midrange drivers, and a new 'Sound Motion' woofer for bass. The rear houses the ports along with a set of physical controls, including Sonos' latest touch interface for play/pause, track skipping, voice activation, and a granular volume slider that mirrors the one in the app.
The Arc Ultra supports all major Dolby audio formats, including lossless Dolby Atmos, and also offers DTS surround support, though notably, there's no support for DTS:X, the 3D Atmos rival. Additionally, you get an Ethernet port for network stability and a single HDMI eARC port (sorry, no extra HDMI input). While the single input might seem limiting, most people today use an external hub or rely on their TV, Apple TV, or PS5 for connectivity.
The lack of a remote might not sit well with some users, but since it's Sonos, that's part of the trade-off. On the plus side, Bluetooth support is finally here, along with compatibility for Wi-Fi 6 and Apple AirPlay 2, allowing for multi-room audio setups. It's also compatible with the Sonos Ace headphones which, by the way, are my favorite pair of headphones.
For me, the biggest difference between the original Arc and the Arc Ultra is that the latter produces noticeably richer, fuller bass. I used the Arc Ultra to stream content from Netflix, JioHotstar, and YouTube, and also listened to music on Apple Music. You may or may not check its specs but trust me, they don't matter when you are in front of the TV, watching something, and hearing the Arc Ultra in action for the first time. That experience itself is on another level.
No matter where your couch is in the room, the sound reaches every corner, and not once did I feel that dialogue articulation dropped. I put the Arc Ultra through various tests, including watching Dolby Atmos content and it was impressive. You can feel the action, thunder, explosions, and cars zooming past as if you are sitting in a movie theater.
The Arc Ultra is a major upgrade over the original Arc. It not only delivers an impressive soundstage but also brings out more nuanced and subtle audio details without losing the important ones something movie aficionados definitely don't want to miss.
If you ask me, the Arc Ultra doesn't try to mimic actual ceiling speakers like those in a traditional home theater setup. Instead, it creates an intense, immersive environment that pulls you into the content and delivers the best experience one could ask for in a living room. I think it's the peak of acoustic engineering that makes the Arc Ultra so effective at what it does. This holds true especially when listening to dialogue: it maintains the original experience and stays true to the creator's intent. The new dynamic Speech Enhancement tool with four different levels (Low, medium, high and max) to choose from also helps the Arc Ultra shines.
I also spent a lot of time listening to music on the Arc Ultra. The audio sounds rich and clean, with excellent stereo imaging and track separation. The big difference between listening to music on the Arc Ultra versus other speakers (including my Apple HomePod) is that it truly sets the mood, especially when you are playing a track like One Night Love Affair by Bryan Adams. That said, audiophiles still prioritise perfect stereo separation, and the Arc Ultra may not reach that level. But for casual listening, it's more than good enough.
Don't expect the Arc Ultra to deliver earth-shattering bass or overly dramatic effects, but every time I watched a movie, I found myself appreciating those Sound Motion woofers. They are super flat and compact, yet capable of deep excursion for maximum air displacement. That's Sonos for you.
As I mentioned earlier, the Arc Ultra is a complete soundbar on its own: you don't need to add another speaker or a set of speakers to get that home theater feel in your living room. But the advantage with Sonos is that you can always add more speakers to enhance the experience even further. It's optional, of course, but if you can afford to invest in additional speakers, even without having a large space, it's always nice to have that extra depth and immersion.
That's when you realise how much value the Sub 4 subwoofer brings, despite its price.
While the Arc Ultra's Sound Motion technology is very effective, especially in producing better bass: it primarily operates in the upper bass and lower midrange region, around 250Hz and above. Simply put, the Sub 4 adds that extra muscle, delivering low-frequency reproduction that the Arc Ultra alone can't quite reach. It's also smaller and it doesn't take up much space. You can even slide it flat, if you want.
Sonos has faced criticism for its app in the past, but things seem to be improving. I launched the app on my iPhone 16 Pro, and setting up the Arc Ultra and Sub 4 was a seamless process. As part of the setup, I connected the soundbar to my network and added it to my existing Sonos system. While the app's layout is still somewhat unintuitive, it's easy to control the speaker and explore its features.
The app includes an EQ, but it's fairly basic: only allowing you to adjust bass and treble levels. However, it does let you set up Sonos' Trueplay technology, which uses built-in microphones to tune the audio to the specific acoustics of your room. The Arc Ultra also supports Sonos Voice Control and Amazon Alexa, both of which can be configured directly within the app.
The Arc Ultra is the best soundbar Sonos has ever made and possibly one of the best soundbars currently on the market. I genuinely feel that way. It sounds magnificent and stands strong on its own without needing any additional speakers, not even the Sub 4. However, if you can afford the Sub 4, go for it.
The integration between the subwoofer and the soundbar is seamless, and together they create an experience that only Sonos can deliver. It's an expensive soundbar: the Arc Ultra alone costs around Rs 1,00,000, and the Sub 4 adds another Rs 84,999. That's definitely pricey, but you are buying into the Sonos ecosystem for a reason. That level of experience doesn't come cheap and carries a premium price tag, for good reason.
Anuj Bhatia is a personal technology writer at indianexpress.com who has been covering smartphones, personal computers, gaming, apps, and lifestyle tech actively since 2011. He specialises in writing longer-form feature articles and explainers on trending tech topics. His unique interests encompass delving into vintage tech, retro gaming and composing in-depth narratives on the intersection of history, technology, and popular culture. He covers major international tech conferences and product launches from the world's biggest and most valuable tech brands including Apple, Google and others. At the same time, he also extensively covers indie, home-grown tech startups. Prior to joining The Indian Express in late 2016, he served as a senior tech writer at My Mobile magazine and previously held roles as a reviewer and tech writer at Gizbot. Anuj holds a postgraduate degree from Banaras Hindu University. You can find Anuj on Linkedin.
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