Sonos Arc Ultra and Sonos Sub 4 Review
The premium soundbar Sonos Arc was able to convince us completely at the time as a sonically perfectly matured and excellently crafted sound system. Now the Arc Ultra, the official successor to the flagship model, is available, which appears almost unchanged on the outside but comes with a modernized setup and optimized sound performance.
Thus, this soundbar offers WiFi 6, Bluetooth 5.3, an HDMI ARC/eARC port as well as a total of 14 high-, mid-, and low-frequency drivers. In addition, there is AirPlay support, Dolby Atmos, and voice control via Alexa or Sonos Voice Control. Via the app, users can also directly access music streaming services such as Amazon Music, Apple Music, or Spotify.
What else distinguishes the 9.1.4 sound system, from its predecessor, which control options are offered, whether a second HDMI port is available to connect other source devices, how high the power consumption is, how the sound is rated in practice, and what the optionally available Sub 4 has to offer or whether purchasing the slim subwoofer is worth it, is all revealed in our detailed test report.
The Sonos Arc Ultra is optionally available in a matte black or white finish, with the black version available for our test. The exceptionally high-quality and flawlessly crafted housing is made of plastic and is largely provided with a perforated pattern.
Thanks to its rounded design, the soundbar looks very slim and modern despite being nearly 1.2 meters wide. The oval-shaped body is placed in a kind of L-shaped mount that forms the base but also includes the rear with the connections and extends as a narrow bar up to the top side.
On the top, you’ll find the most important touch controls, while the connections on the back are concealed in an indentation and consist only of a LAN port, an HDMI eARC/ARC interface, and the connection for the power cable. There is also a physical Bluetooth button and a mechanical microphone switch that can turn off the built-in far-field microphones. Also on the backside are two screw holes for the optional wall mount offered in the Sonos shop. Four small LEDs on the front, which can light up in different colors, inform about the current operating status.
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Inside, a quad-core A55 processor with 1.9 GHz and seven angled dome tweeters, six mid-range drivers, and one woofer are driven by a total of 15 Class-D amplifiers. The particularly complex woofer is made of two opposing cones driven by four motors and two amplifiers. Bluetooth in modern version 5.3 is available for wireless music streaming. With WLAN (WiFi 6), AirPlay, and multiroom, additional wireless connection options are also included.
The Sonos Arc Ultra, like its predecessor, is delivered without an external subwoofer, although the Sub 4 is optionally available for purchase and was part of our test scenario. The active premium WLAN subwoofer, just like the Sonos soundbar, is available in black and white. The casing has equally high-quality looks and feel. The most striking feature is the rectangular recess that runs through the center of the housing, similar to the Sonos Sub Mini. In this recess, the two elliptical 5 × 8 inch force-canceling woofers face each other.
Otherwise, on the predominantly smooth design, you will find a connection button with LED display on the front and, on the underside, the power connection and a LAN port (10/100). The slim subwoofer, which weighs about eleven kilograms, also offers WLAN (WiFi 6) and the Trueplay function, which perfectly adjusts the acoustics of the room to your own Sonos system.
Setup, Operation, and Features
As usual with Sonos products, users cannot avoid the Sonos app introduced in May 2024, which first requires the creation of a free Sonos account by email registration. However, this app had certain technical hurdles from the start that still partially persist to this day. During our initial setup, none of this was noticeable, as the installation wizard guided us through the steps clearly, which ended with an update in our case.
The setup is similarly straightforward with the Sub 4, which uses NFC technology. In our test scenario, the entire entertainment system was fully operational after about ten minutes. Connecting the soundbar to the TV is also easy since there is only one HDMI ARC/eARC port, which must be connected to the TV’s HDMI (e)ARC input. Note that only TVs with an eARC port reliably support all audio formats, including Dolby Atmos and TrueHD.
Control is mainly handled via the new Sonos app, which, among other things, makes it possible to switch the input or audio source, make sound adjustments, or change the volume. You can also integrate various music services such as Spotify or even individual radio stations like “80s80s” directly into the app and play them there, so everything can be bundled in one place. In our test, the app worked largely reliably and smoothly. Only the search function, which is supposed to help you find specific songs, albums, artists, or radio stations, was rarely truly helpful.
Within the app, users also have the option to connect to an Amazon account to use the Alexa voice control in the usual way. Alternatively, Sonos Voice Control is available, which in principle offers the same control options and functions. For example, users can set a timer, ask for the weather, start a radio station, or switch between Bluetooth and TV mode.
Note that there is still no German voice output implemented, so commands must be given in French or English. Sonos basically plans to make its voice service available in German in the future, but the manufacturer has not given a specific time for this yet. In everyday use, however, the touch buttons on the top of the device are sufficient, including a touch slider that allows you to adjust the volume by swiping. Three more buttons allow you to play, pause, and skip streamed audio tracks. The absence of its own remote is well compensated by this and by the fact that the main control options can also be accessed with the TV remote.
“Rich movie sound with the elegantly designed Dolby Atmos entertainment system from Sonos”
The slim soundbar is network-capable (WiFi 6), supports AirPlay, and allows for wireless (music) streaming via Bluetooth 5.3. In our test, such a connection was easy to establish and remained absolutely stable and without interruption over multiple rooms at a distance of well over ten meters. Also available is the TV Audio Swap function, which lets you transmit the TV sound at the push of a button to the Sonos Ace headphones, for example, so as not to disturb a partner sleeping next to you. Physical connection options such as an aux input or a USB port are not available.
Sound Quality
In the Sonos app, there are various options for customizing the sound. For example, you can adjust bass, treble, and balance of the audio pro between –10 and +10 decibels. For the subwoofer, an independent level value between –15 and +15 can be selected. There is also a volume limit, speech enhancement, a night mode, and the Trueplay function. The latter is software that measures the room acoustics with emitted tones and the built-in microphones and perfectly adjusts the equalizer accordingly.
When playing music, which we tested first, we noticed the strong bass performance as particularly remarkable. This is made possible by the so-called Sound Motion technology, referring to the new double membrane woofer inside. With it, the Arc Ultra already delivers very precise bass without an additional subwoofer, which in our test scenario came across surprisingly punchy. For less bass-heavy music, the added value delivered by the Sub 4 is accordingly limited.
However, it’s a different story with tracks featuring more dominant bass lines like “Yeah” by “Usher” or “Murder She Wrote” by “Chaka Demus & Pliers,” where the already rich low-end foundation is taken to a whole new level by the Sonos subwoofer. The system scored particularly well here with its powerful bass vibrations that transmitted directly to our legs, practically pushing us onto the dance floor. Apart from that, the Arc Ultra delivers an extremely detailed sound image across various genres and songs such as “Friends in Low Places,” “Living on a Prayer,” or “Daydream Believer.” Alongside the snappy bass, the striking midrange and clean, detailed highs were in no way inferior. We particularly remember the extremely distinctive violin parts from “Clint Mansell – Summer Overture” from the film “Requiem for a Dream.”
Here, the Dolby Atmos soundbar managed to reproduce the already very emotional or memorable track in a maximally authentic way, letting us physically feel every note. The Arc Ultra is therefore definitely well suited for use as a hi-fi system.
However, the performance in movie playback is more crucial, which we tested with the action-packed blockbuster “Godzilla vs. Kong.” As a starting point, we chose the first big clash of the two monsters amidst a US warship fleet. In the course of the fighting, ear-splitting explosions from detonating ships and planes as well as from firing aircraft guns lined up in quick succession. The Sonos Arc Ultra managed to bring the frantic on-screen action perfectly into our entire test room, gripping us in a way that we had seldom experienced before.
In combination with the Sonos subwoofer, an even fuller, more forceful, and more powerful soundstage was produced, making those effects feel much more tangible and immersive. The effective Dolby Atmos playback also contributed to an all-around impressive overall experience. Thus, the sound effects were very convincingly perceptible from all directions, pulling us even deeper into the sometimes chaotic on-screen happenings for an absolutely immersive experience. Yet even with normal TV content like evening sitcoms or game shows, the Sonos Arc Ultra performed excellently and offered flawless speech clarity with impressive strengths.
Tech Specs
Sonos Sub 4 Specs
| Parameter | Value |
|---|---|
| Manufacturer | Sonos |
| Model | Sub 4 |
| Dimensions (W × H × D) — Original (cm) | 40.2 × 38.9 × 15.8 |
| Dimensions (W × H × D) — Scaled (largest side = 10) | 10 × 9.7 × 3.9 |
| Weight | 11.79 kg |
| Colors | Black, White |
| Connections | LAN (10/100) |
| Hardware Features | |
| • Device Display Type | Status LED |
| • Amplifier Technology | Class‑D |
| • Number of Bass Drivers / Diameter | 2 drivers / 5 × 8 inches |
| • Frequency Range | 25 Hz (lower limit) |
| • Output Power (in W) | Not specified |
| • Wireless | Yes |
| • Active / Passive | Active |
| • Power Switch | No |
| Functions | |
| • LAN / WLAN / NFC | Yes / Yes / Yes |
| • App Control | Yes (via Sonos app) |
Sonos Arc Ultra Specs
| Parameter | Value |
|---|---|
| Manufacturer | Sonos |
| Model | Arc Ultra |
| Dimensions (W × H × D) — Original (cm) | 117.8 × 7.5 × 11.06 |
| Dimensions (W × H × D) — Scaled (largest side = 10) | 10 × 0.64 × 0.94 |
| Weight | 5.9 kg |
| Colors | Black, White |
| Wall Mount / Mounting Bracket Included | Yes / No |
| Connections | – Audio: HDMI ARC/eARC- Data: LAN (10/100) |
| Hardware Features | |
| • Frequency Range | Not specified |
| • Amplifier Technology | Class‑D |
| • Device Display Type | Status LEDs |
| • Number and Type of Built‑In Speakers | 14 total:7 angled dome tweeters6 mid‑range drivers1 dual‑membrane woofer |
| • Sound System Configuration | 9.1.4 |
| • Supported Audio Formats | Stereo PCMDolby DigitalDolby Digital PlusDolby AtmosDolby TrueHDMultichannel PCM / Dolby Multichannel PCMDTS Digital Surround |
| • Output Power (W) | Not specified |
| • Subwoofer | Optional |
| • Remote Control | No |
| Functions | |
| • Bluetooth / NFC / AirPlay / LAN / WLAN | 5.3 / No / AirPlay 2 / Yes / (802.11 a/b/g/n/ac/ax) |
| • Multiroom | Yes |
| • Voice Control | Alexa, Sonos Voice Control |
| • App Control | Sonos app |
| • Preset Sound Modes | Speech Enhancement, Night Mode |
Measurement Data
Power Consumption (W)
- Standby: approx. 4.2 W
- Operating: approx. 15.3 W
Annual Cost: € 15.99
(Calculated at an electricity price of 32 ct/kWh. The figure is based on 365 days of mixed use with an average of 195 minutes/day.)
Conclusion
The Sonos Arc Ultra is a clear evolution of its predecessor and impresses with an outstanding combination of cutting-edge technology and superior sound quality, shining in both music and movie playback. Those who really want to make their four walls shake can also rely on the optionally available Sub 4, which further boosts the already powerful overall setup.
The extensive features include, among others, the 14 integrated speakers with Dolby Atmos support, Bluetooth 5.3, and WiFi 6. Another positive aspect is the user-friendly operation, which is ensured by the possible use of the Sonos app, voice control, and the touch controls. The Sonos system is not exactly a bargain, but considering the resulting premium experience that both audiophile music lovers and home theater enthusiasts will appreciate, it’s worth every cent. Accordingly, it ends up with an overall result of 9.4 for the Arc Ultra and 9.3 for the Sub 4, each earning the top rating of “very good.”
Scope of delivery: Soundbar Sonos Arc Ultra · Power cable (2 m) · HDMI cable (1.5 m) · User manual
Scope of delivery: Subwoofer Sonos Sub 4 · Power cable (2 m) · User manual
PRO
Dolby Atmos, TV Audio Swap function, WLAN/LAN, Multiroom, Bluetooth 5.3, AirPlay, HDMI ARC/eARC, touch control, control app, voice control
CONTRA
no Aux-in, no optical S/PDIF input, no USB port, no remote control, no wall mount included, account required
Sonos Arc Ultra Evaluation
Overall Score: 94.0% (Very Good)
Criteria Breakdown
- Sound Quality (50 %): 96 %
- Workmanship (10 %): 95 %
- Operation (15 %): 93 %
- Accessories (10 %): 88 %
- Features (15 %): 90 %
- Bonus: –
- Price/Performance Index: 10.63
Sonos Sub 4 Evaluation
Overall Score: 93.0% (Very Good)
Criteria Breakdown
- Sound Quality (50 %): 97 %
- Workmanship (10 %): 97 %
- Operation (15 %): 93 %
- Accessories (10 %): 76 %
- Features (15 %): 87 %
- Bonus: –
- Price/Performance Index: 9.67
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