Sonos Arc Ultra and Sub 4 review: A match made in home theatre heaven

India Today

17-06-2025

The word 'ultra' stands for something that goes way beyond what many perceive as usual or ordinary. Regardless of whether you use it as a prefix or a suffix, it is widely understood, what we're dealing with is something extraordinary. Especially in consumer tech circles – where it gets thrown around a lot these days – the word ultra represents the latest and absolute greatest thing a brand can make.But here's the thing: sometimes, it can get tricky. What if someone made an ultra-capable thing, but did not call it ultra? Marketing would say they missed an opportunity. But what if that thing was so far ahead of its time, it didn't matter what they called it? What's in a name, right? But here's another thing: what if the same company goes and launches a follow-up model? Only this time, it names it ultra.You could say that this brand – which is called Sonos – chooses its words with extreme caution. You could also say it has a crack marketing team, which decided to hold off 'overselling' its product – the Sonos Arc – with fancy naming knowing full well, its engineers could pull off something even more impressive, something truly worthy of the title ultra, even if it takes another five years to get there.As unbelievable as it might seem, it is business as usual at Sonos, where a lot of these decisions are in fact being taken by the very people who are making these products. So, despite what you may hear about it – based on recent events – this is a company with a great culture. We don't know where it will go from here, but that is a subject for another day and another discussion. For now, what's fascinating to me is how on earth Sonos managed to make an already ultra-class product, even more ultra. We'll try and find out in this India Today Tech review of the Sonos Arc Ultra premium soundbar, and its companion piece (but completely optional), the Sonos Sub 4 subwoofer.advertisementSonos Arc Ultra and Sub 4: Design and buildSonos, like Apple, is known – and revered – for minimalist design. Everything from the box to its contents and the device inside mirror the sentiment as if it were a ground rule. The Arc Ultra and Sub 4 are no exception. Unboxing is an experience and Sonos wants you to feel and enjoy it. Strange that a piece of tech brings joy like this, but in a world that is full of complexities, anything that makes your life simple is priceless. But I digress.The Arc Ultra retains the sleek, elongated, and gracefully curved silhouette that made its predecessor – Sonos Arc – an instant design icon. Available in stand-alone white and black, it is designed to sit elegantly beneath large televisions, or you can mount it on your wall. Either way, it has a general propensity to blend well with the dcor if you have a large room setup. I won't go into the specifics, but the soundbar is 117.3 cm in width, 8 cm in height, and 11 cm in depth. It weighs 5.9 kg. So, you can go figure.advertisement
It is not huge per se, but it is not small, like say, the Ray or Beam, other soundbars that Sonos makes. But – and this is the real kicker – it is noticeably more compact than the Arc, meaning that Sonos was able to shrink a lot of things, add more things, and yet, make a relatively smaller product. A newly included back panel now provides more convenient access to controls and ports. Surely, people who've had no prior access won't be able to relate, which is why, if possible, you should visit a Sonos store near you. The difference – and the spec upgrade – will blow your mind.The Sub 4, with its unique central opening, doesn't stray very far from the Sub 3 in look and feel. It is still striking to look at, yet very tasteful and functional. You can put it vertically or horizontally, much like the PlayStation 5.Sonos Arc Ultra and Sub 4: SetupThe simplicity extends, or rather, it blends into the setup process as if it were one entity. You start by plugging in the Arc Ultra to power and connecting it to your TV's HDMI eARC port. The Sub 4 needs to be plugged into a separate power outlet wherever you feel it is convenient (you don't need to connect it to the TV or even the soundbar). Once ready, open the Sonos app on your phone or tablet, at which point, it will detect new Sonos devices nearby. Follow the on-screen prompts to add the Arc Ultra to your existing Sonos system or create a new one.Once the soundbar is set up, the app will prompt you to add the Sub 4. With a few taps, it pairs wirelessly with the Arc Ultra. The setup is now complete. You can choose to start using it at this point or, enable Trueplay, which is basically Sonos' version of Apple's Colour Balance, but for audio. It basically lets you calibrate the soundbar to the shape and confines of your room so it can deliver – per Sonos – the best possible sound stage and tonal balance.advertisementIt is all technical jargon and there is an off chance, most people would simply skip it much in the same way they do with instruction manuals. But it doesn't take up a lot of your time and doesn't require you to jump through multiple hoops to call it a menial and cumbersome task, so I'd say you should go ahead with it. Watching, or rather listening to your soundbar firing invisible beams of sound in the air like in Sci-Fi movies, was definitely not something that I had signed up for. But I am glad it exists and with Sonos finally opening the platform to Android, more people can access it now. Previously, Trueplay was an Apple-exclusive feature, meaning that only people with iPhones could use it.advertisementSonos Arc Ultra and Sub 4: Sound performanceWe've established that the original Sonos Arc was a strong performer, so, what does the Arc Ultra do, its predecessor couldn't? The devil, apparently, lies in the details. This starts with the hardware set itself. The Arc Ultra simply has more powerful hardware. Despite its tighter dimensions, Sonos was able to put 15 Class-D digital amplifiers and 14 drivers inside it while the Arc had 11 of each. That's four more amps and three additional upwards and sideways-firing drivers. Sonos even says the design was modified internally for better acoustics. What you might be more interested to know is, the Arc Ultra has a 9.1.4 Dolby Atmos surround sound profile. The 5.0.2 Arc, even though it sounded amazing, was technically less immersive even by Sonos's own spec standards.The Arc Ultra is also getting the first dibs at its new Sound Motion technology, which is basically a new – and proprietary – type of transducer that takes up less space and yet, theoretically delivers double the bass response. The idea is to let the soundbar itself do more of the heavy lifting even before the subwoofer kicks in. In the real world, what this means is that the Arc Ultra delivers a surprisingly and substantially more robust low-end while freeing up the other drivers to focus on mid-range and high-frequency clarity. Speech enhancement is also getting an upgrade with more fine-tuning options that work silently in the background to enhance dialogue, which is often a pain point for soundbars. Maybe you're getting the sense that this is a very thought-out product, the work of scientists and engineers who worked day in and day out to perfect the internal structuring, so everything has a distinct purpose. Good, we're on the same page.advertisementWhile the Arc Ultra holds its own, pairing it with the Sub 4 – unsurprisingly – unlocks greater immersion (provided you're willing to loosen your wallet). Compared to the Arc Ultra, the upgrades here are less headline-grabbing. In fact, they are incremental at best, but frankly speaking, that is okay. There was nothing wrong with the Sub 3. It is still a compelling system, but the newer generation brings promise of more polish and refinement. Also, from pure marketing speak, your mind would say, it should work better with the Arc Ultra even if your heart says, there's merit in saving some hard-earned cash. Both are right, which is why it helps to know that the Sub 4 is an optional purchase, not a necessity. You can pick and choose your poison. Whatever works for you.advertisementInternally, the Sub 4 has dual 5- x 8-inch elliptical woofers. While they do deliver deep and impactful bass, what stands out more is how they do it with full and total control. Subwoofers often tend to run around like headless chickens but the Sub 4 walks into a room and owns it. Its force-cancelling design, of course, plays a key role in this, its two inward-facing woofers virtually eliminating cabinet vibration, meaning you get pure, unadulterated bass without any annoying distortions, even when you crank up the volume. But truth be told, this was mostly expected. What's surprising is how quickly it can plunge down to something like 25 Hz, letting you feel every explosion, every rumble of thunder, and every beat of a bass drum as if you were right there. Not many subwoofers can brag about a wide soundstage like that.Together, the Arc Ultra and Sub 4 work like a dynamic duo. They work to each other's strengths. They lift each other up when the going gets rough. More specifically, the Sub 4 takes over the demanding low-frequency duties, allowing the Arc Ultra to focus its substantial power and drivers on rendering the mid-range and high frequencies with even greater precision and openness. The synergy creates a wider, deeper, and more open soundstage.Sonos Arc Ultra and Sub 4: ConnectivityThe Sonos Arc Ultra also brings a much-needed connectivity upgrade. While Wi-Fi 6 lets it stream high-resolution audio, with Bluetooth 5.3 support, you can now also stream directly from mobile devices. It might seem small, but this quality-of-life feature was missing from the original Arc for some curious reason. Then there are the usual suspects: HDMI eARC, AirPlay 2, and voice control, though this is still limited to Amazon Alexa and Sonos's own voice control offering. While not a deal-breaker, the absence of DTS:X support might be a minor concern for a very niche audience with extensive DTS:X media libraries.Sonos Arc Ultra and Sub 4: Should you buy?The Sonos Arc Ultra at Rs 99,999 and the Sonos Sub 4 at Rs 84,999 offer an amazing home theatre experience. The Arc Ultra is a big step up from the original, with more powerful insides and a fuller Dolby Atmos sound that really pulls you into the content. Even on its own, it delivers impressive bass.However, if you want the absolute best sound, adding the Sub 4 makes a huge difference. It handles the deep bass perfectly, letting the Arc Ultra focus on clear voices and detailed sounds. Together, they create a wider, richer sound that fills the room. Plus, with Bluetooth and better sound tuning for Android phones, these Sonos products are a smart buy for anyone serious about great home audio despite their premium price tags. It is truly a match made in home theatre heaven.