Sonos Arc Ultra review: the minimalist soundbar with revolutionary bass

Heir to the first soundbar from the Sonos brand, the Arc presented more than four years ago now, the Arc Ultra is not intended to be a simple evolution, but a product reworked from A to Z, at least on the sound part. The manufacturer does not overturn the aesthetic codes for the occasion since it opts for the finesse and length design of the first model. Above all, Sonos once again allows itself to combine advanced connectivity with Spartan connectivity.

In addition to a slight stylistic alteration, the Arc Ultra differs from the Arc by a more ambitious acoustic formula with an increased number of speakers. This arrangement allows, according to Sonos, greater immersion, as well as bass optimization symbolized by the integration of a single Sound Motion type woofer, technology integrated for the first time.

Price and availability

The Sonos Arc Ultra has been available since October 29, 2024 for a price of €999. This model is available in two versions: white (tested version) and black.

Test conditions

We tested this model under firmware version 1.41.1.8 with the Sonos app version 16.4.4.

Construction

100% Sonos, the design gives pride of place to minimalism. The design of the product is pure, without roughness or accident, a purity which is found in the unalterable tone of the product (white on our test version). Only the thin base placed at the rear, which accommodates the connectors and the control panel, provides some angular accents… and then again. Some will find this approach almost caricatured, but it is this radical design that has made the brand successful.

Although impeccable, the manufacturing is nothing surprising or premium. Made entirely of plastic, the Arc Ultra frankly lacks refinement. For the rest, nothing to say: the whole thing is dense and the assembly without visible screws contributes to the very Apple appearance of the soundbar.

Accessories

Like the design, the Sonos packaging is cleverly minimalist. The brand only delivers a semi-proprietary mains cable, being one of the only ones compatible with the recessed base of the product, and a very short (1.5 m) HDMI cable. Both are in Arc Ultra colors.

Wireless connectivity & broadcasting

As noted above, Sonos is continuing its quest to virtually eliminate all forms of connectivity. The Arc Ultra is not designed to be an audio center, nor is it intended for association with audio elements from other manufacturers.

The device has an HDMI eARC port and an RJ45 Ethernet port, period. Quite pettishly, Sonos charges a high price for the universality of the optical port since a small HDMI to optical converter is sold on the manufacturer's website for €29. For the rest, no HDMI input, no analog input and no output for external subwoofer.

Moving to the connected dimension, things are very different. In addition to the integration of a fairly modern Bluetooth 5.3 chip, the product relies on the usual Sonos-style connectivity. The Arc Ultra is therefore AirPlay 2 and Spotify Connect compatible. The manufacturer obviously still ignores Google Cast.

The historical strength lies in the integration of the brand's connected ecosystem. Like previous soundbars, the Arc Ultra goes further than a simple multiroom approach. It can be combined with various elements to optimize immersion: Era 300 or Era 100 as Surround/Atmos speakers, and support for various wireless subwoofers. Note also the possible association with the recent Ace helmet.

User experience

Sonos obliges, the user experience relies entirely, or almost, on the dedicated Sonos app. Everything would be for the best in the best of all possible worlds if it had not been the main subject in 2024 of a massive massacre linked to its modification for the release of the Ace helmet. Rendered almost unusable (at least for some users) for months, the Sonos application is gradually repairing itself, but still bears the scars of this historic crash through some bugs and pairing difficulties previously inconceivable.

Fortunately, the app generally retains what makes it effective, resulting in an ultimately frustration-free experience. As is often the case, we could only wish for a few more sound adjustments, including a real equalizer.

In the absence of a dedicated remote control (possibility of adding an infrared remote control), only the touch panel present at the top of the bar allows you to do without a smartphone. The controls are rather complete, since they provide navigation, management of sound groups and Sound Swap, as well as triggering the voice assistant. Best of all, volume adjustment relies on a surprisingly precise touch slider.

Unsurprisingly, the integrated interface consists of a single RGB status LED. This provides some information on the type of input (wifi, Bluetooth, HDMI eARC) or possible connection errors, no more.

Voice recording

Like all recent connected products from Sonos, the Arc Ultra is compatible with Alexa (Amazon) voice assistants and especially Sonos Voice, its home assistant very gifted for tasks specifically linked to this ecosystem.

Unfailingly reliable, the microphones allow the product to capture the voice in all situations. Whether with music in the background or conversation noise, voice detection is almost flawless.

Audio

The almost unchanged design of the Arc Ultra version could lead us to fear the worst in terms of sound innovation, but the observation is quite different. Sonos has here intelligently exploited the acquisition in 2022 of a very promising Dutch manufacturer, Mayth, which had developed an architecture for bass speakers, called Heartmotion.

Taken and optimized by Sonos, renamed Sound Motion, this technology consists of an assembly of two speakers mounted back to back, the particularity of which lies in the eccentric placement of the motors. The latter are mounted in pairs diagonally and connected/stiffened by an openwork bridge system.

The aim of this assembly is to reproduce maximum bass in a minimum of space in order to free up space for more midrange and treble drivers. The device thus increases to 14 speakers in total, compared to 11 previously, by multiplying the tweeters. A sound revolution? Not quite, but it is obvious that the Sonos Arc Ultra constitutes a fairly significant upgrade compared to the first version, and a real performance given the general volume.

The most notable improvement clearly comes from the Sound Motion woofer which, despite the thinness of the bar, finally brings a nice extension in the low end, a real energy in this register, which is simply astonishing. Without replacing a good dedicated box, this assembly manages to be more than sufficient for small rooms (20-25 m²). The whole thing is not perfectly linear at the bottom of the spectrum, because a certain drop sets in below 80 Hz. However, this drop is quite regular, so much so that the Arc Ultra manages to exist without poorly up to 40 Hz, or even a little below.

The recipe is obviously not magical, but what was lacking in the previous bar, such as controlled distortion below 100 Hz, is present here. Only the slightly more purring than truly impactful side of the Sound Motion woofer seems truly perfectible to us. Likewise, the placement of the subwoofer at the right end of the product gives a slightly localized side to the bass. These two criticisms are slight, but constitute points of improvement for future bars.

For the rest, we are clearly on familiar ground. The Sonos personality shines through quite widely in this model with its balanced sound, which distills slightly recessed highs. The latter, quite soft, but with a slight hint of sparkle, offer the product excellent versatility, the Arc Ultra being equally at home with music and video content. Overall rich, the bar is unfortunately not free from inaccuracies in the treble and even in the midrange. The observation is there, technical progress is only really felt on the bass.

Note here that the effect of True Play calibrations is mainly in the bass. Tempering the few possible overflows of the product, the advanced True Play improves the precision of the rendering, while reducing the vibrating side in the bass. Classic calibration is, as is often the case, much more subtle.

Sound spatialization

Atmos model, the Sonos Arc Ultra manages to do better than the Arc, all without being able to compete with the few leaders of the genre, Sennheiser Ambeo Soundbar Plus in the lead. By multiplying the speakers, Sonos has managed to retain the successful surround effects of its predecessor, while offering a certain verticality to the sound. The sound reproduction does not leave a feeling of 3D bubble, notably due to the absence of rear effects, but the precision of the rendering is there. By further improving the sound elevation, which here fails to go beyond the scope of the TV, the manufacturer will reach a milestone. This observation is all the more valid because if a vertical adjustment of the sound is present in the app, its effect is too subtle to make a difference.

Well projected forward, the only fault of the dialogues is a slight imprecision, especially at high volume, an imprecision which is quite well illustrated by the slight distortion bump in the midrange.

How does the rating work?

A demonstration of compactness and minimalism, the Sonos Arc Ultra is an effective evolution of the Arc formula, largely supported by the Sound Motion speaker. Surprising in the bass, as pleasant in video as in music, it constitutes a devilishly effective all-in-one product. Despite everything, its extremely simple connectivity and its perfectible management of the Atmos dimension serve it poorly compared to competing bars, certainly less stylish and compact, but which offer more for an equivalent price.