On a piece of furniture, a soundbar nearly 1.18 m long needs a surface wide and deep enough to accommodate it. Mounted on the wall below the screen, it no longer needs furniture, and the sound travels in line with the picture. This Sonos mount holds the Arc Ultra as close to the wall as possible and disappears behind it once the soundbar is in place. The soundbar automatically detects its wall-mounted position and adjusts its bass.
The mount consists of a thin plate screwed to the wall, onto which the Arc Ultra hooks from the back. The two supplied knobs screw by hand into the threaded inserts on the back of the soundbar. The soundbar is then slid down until the knobs slot into the notches in the plate. The soundbar sits flush against the wall, with no bracket or arm protruding underneath: viewed from the front or at an angle, only the soundbar remains visible. The plate weighs 0.55 kg and supports a 5.9 kg soundbar. The power and HDMI cables connect to the back of the Arc Ultra before mounting, then run down behind it towards the mains socket and the TV.
A speaker placed flush against a wall does not sound the same as one on a piece of furniture. The wall reflects some of the low frequencies back into the room, and this bass adds to the bass coming directly from the soundbar. The bass increases in volume, sometimes to the point of becoming overpowering or making the partition resonate. The Arc Ultra detects that it is wall-mounted and automatically changes its equalisation to control this resonance, without requiring any adjustments in the app. The correction affects the bass, the part of the frequency spectrum most sensitive to proximity to a wall. The soundbar’s Sound Motion module, a flat woofer with four motors and dual diaphragms, is therefore adjusted from the very first listen. Bass, treble and loudness settings remain available in the Sonos app to fine-tune the result to your taste.
Sonos recommends installation below the TV. Mounting above the screen remains possible when the TV’s height or the room layout requires it.
In either case, leave at least 10 cm between the soundbar and the TV. Two of the Arc Ultra’s tweeters face upwards and create the Dolby Atmos height channels by reflecting sound off the ceiling: the soundbar needs space above it. When installed below the screen, this 10 cm gap corresponds to 14 cm between the top edge of the plate and the bottom of the TV. A supplied positioning guide lets you transfer this measurement to the wall. It looks like a simple packaging spacer, so it is best not to throw it away before installation.
The touch controls must remain facing upwards. Each end of the soundbar must be at least 30 cm from a wall or obstacle. Avoid room corners or enclosed recesses.
The box contains the plate, the positioning guide, the two knobs, six screws and six wall plugs. First, hold the plate against the wall to mark the screw positions, then drill according to the wall material. In a wooden stud, a pilot hole made with a 3 mm drill bit is sufficient, and the wall plugs stay in the box: they are not used in wood or plastic. Plasterboard without a stud, or a plaster, concrete or brick wall, requires an 8 mm drill bit and the supplied wall plugs.
The plate is then secured with a Phillips screwdriver or a power screwdriver, using a spirit level to check that it is horizontal. The arrows engraved in the centre of the plate must point upwards. All that remains is to screw the knobs into the back of the soundbar, connect the cables and hang the assembly.
Yes. Sonos markets it in France under the name “Wall Mount for Sonos Arc and Arc Ultra”, and both soundbars attach to it in the same way. Automatic bass correction when wall-mounted applies to the Arc Ultra.
Yes, the Arc Ultra also fits on the Arc mount. However, the two soundbars have different dimensions, and the old mount may remain visible from certain angles. The dedicated mount stays completely hidden behind the Arc Ultra.
Automatic correction addresses wall resonance. Trueplay goes further: it measures how sound reflects off the walls, furniture and other surfaces in the room, then adjusts the equalisation. After a change in position, a new measurement takes the soundbar’s location into account. Quick calibration uses the soundbar’s microphones and works with both iOS and Android, provided the microphone switch on the back is in the up position. Advanced calibration is exclusive to iOS devices and requires about five minutes of walking around the room with your phone in hand. It delivers better results in larger rooms.
No. The mounting plate holds the bar flat against the wall, with no joint or arm: the bar follows the orientation of the wall. It must never be mounted vertically or on its edge.
Simply lift the bar to release the knobs from the notches, then pull it away from the wall. The mounting plate stays in place, and the bar hooks back on by sliding it down, just as when it was first installed.
The Arc Ultra comes with a 1.5 m HDMI cable and a 2 m power cable. The TV’s HDMI ARC or eARC port and a power outlet must therefore be within reach. It’s best to check this before drilling, especially when mounting above the screen or if the cables need to run through cable trunking. The power cable cannot be replaced with a longer one from another brand, as a cord not supplied by Sonos voids the soundbar’s warranty.
The thumbscrews screw into the Arc Ultra’s mounting inserts, which have M5 threads with a 0.8 mm pitch over a length of 6.5 mm. A replacement screw must match this thread to avoid damaging the inserts.
Pierre
I haven’t needed to use it, but it’s a very good, high-quality product.
Comment from 25 August 2025 — Experience from 14 August 2025
