Devialet Phantom Ultimate 108dB Active Speaker Review

Best known for its esoteric amplification, this French high-end specialist has more recently branched out into making earbuds, portable speakers and a soundbar. The Phantom Ultimate 108dB is Devialet’s latest active speaker design, sitting above the more compact Phantom Ultimate 98dB and superseding the original Phantom I 108dB.

The Ultimate 108 is reasonably compact at 255x246x343mm [HxWxD] but weighs a hefty 11kg. The dimensions don’t tell the whole story – this is no simple rectangular or chamfered box, as the cabinet is a curved work of art. Equally at home on a credenza or a stand, it could be the simplest aesthetic addition to your home. It recognises that at this level, active speakers need to create a sense of beauty whilst also being fully functional.

It crams a vast amount of Devialet’s technology inside, and the end result is a claimed 108dB maximum sound pressure level (SPL) at 1 metre. This is very loud, and more than most will ever need, I suspect. For example, during my listening sessions, I never exceeded the halfway volume marker in my 33 square metre listening room.

Jean-loup Afresne is Devialet’s Chief Product and Technical Officer, and a veritable fountain of knowledge. He’s responsible for the latest generation of drive units, which he says meet the exacting standards needed to attain the required level of sonic and mechanical performance. The driver complement includes a 25mm aluminium dome tweeter, a 130mm aluminium coned midrange driver and two 200mm opposed, side-firing ABS convex coned woofers. These are configured in a push-pull configuration within the compact 6-litre sealed enclosure.

A cool 1,100W of amplification is deployed to the drive units, and this accounts for at least some of this speaker’s considerable weight. The woofers work up to 250Hz, the midrange driver from 250Hz to 2kHz, and the tweeter from 2kHz to 35kHz. Crossover points are optimised for driver efficiency and fidelity, the company says. The Devialet app includes a six-band equaliser to attenuate or intensify a specific frequency band to shape the output for more personalised listening across the selected audio mode.

Afresne says there are three design pillars of the Phantom 108, the first being acoustic excellence. Claimed frequency range is a seriously impressive 14Hz to 35kHz (-6dB), thanks in some part to the company’s bespoke Analog Digital Hybrid (ADH) amplification. Second, Devialet’s new software platform and advanced connectivity must provide a modern user experience. The third pillar is the aesthetic and user interface design. Physically, this latest Ultimate 108 has minor cosmetic updates with a cleaner tweeter grill and new capacitive touch buttons for improved user interaction.

Getting Going

The aforementioned Devialet app – available on Apple and Google platforms – is required for initial setup and to configure and optimise the rich feature set. Delving into the app, one can set two units up as a stereo pair or dual mono. Primary sonic tailoring options include a Night Mode with reduced bass output, numerous audio modes to emphasise specifics of music, movies or even podcasts. The speaker output monitoring actively tunes the frequency response according to what it hears as the in-room frequency response.

This product supports Airplay and Google Cast, is Roon Ready, and has UPnP, Tidal Connect and Bluetooth 5.3 functionality. Qobuz is on Devialet’s roadmap for the 2026 release.

Integrating these speakers into my listening environment was hassle-free and ready in minutes. Devialet simplifies installation by producing a range of stands and a wall mount, plus a matching remote control. The Phantom 108s were connected via Isotek EVO3 Premier power cables to an Isotek V5 Aquarius power conditioner. In my room, the pair worked best about 80cm from the side walls and 60cm from the rear wall.

The Listening

I tried to find a niche for the Ultimate 108 across musical genres and varying applications – including a multi-room setup, a dedicated 2-channel stereo pair and as home theatre front speakers. Each time I came away grinning, as in every situation, this active speaker system shone. It always sounds clear, unforced, open and extended. Bass is amazingly well extended and shows great control and force. Midband is detailed, and treble is clean, crisp and spacious. There’s a fine sense of rhythm and dynamics, too.

In my listening room, I found the monitor setting removed some upper bass mid warmth and a sliver of upper mid forwardness – so this is what I settled on. This done, the thrumming bassline of Michael Kiwanuka’s Floating Parade filled the room and had realistic texture and body, but didn’t overload it. Orchestral strings floated above the rest of the soundstage with admirable clarity. Vocals were smooth and tonally authentic, while the backing singers were as impactful as the string section.

Races are Run by Madisson Cunningham and Andrew Bird served up an expansive soundstage, and inside this the vocals sounded quite haunting. The fiddle plucking had wonderfully intricate texture, alongside razor-sharp speed and decay. Drumming was taut yet suitably powerful, and the guitar work was impressively nuanced.

Moving to a moodier track from Lady Blackbird, When the Game is Played on You had this Devialet speaker system pulling out all stops to communicate the music’s emotion. The broad soundstage contained plenty of percussive detail, alongside impressive keyboard sounds and guitar licks. Vocals sounded really stirring as they battled with the twanging electric guitar and solid electric bass line. All the strands of the mix were pieced together seamlessly, letting me enjoy the power of this piece of music.

Going from 2-channel stereo mode to working as home cinema front speakers, the soundtracks of Terminator, Dune and Dune: Part Two had a great impact. Selecting the Movie sonic signature further enhanced the experience, with a panoramic soundstage and excellent image placement – all delivered with great dynamic range and authority. Whether playing quietly or loudly, the Ultimate 108 served up an impressive aural imprint.

Splitting the pair up into two mono units spread across my adjoining rooms, I used the AirPlay interface to provide a truly coherent multi-room audio experience. No lag, no dropouts, just clear and coherent music. I found my iPhone’s volume up/down buttons for AirPlay too coarse, so I reverted to the Devialet app, which could provide the level of granularity to dial in your preferred level.

For me, the only issue with this speaker system was positioning, as the side-firing woofers present their own placement challenges in some rooms. You do need some sidewall clearance to contain the bass output. Also, this speaker is quite deep, so you’ll need to think about how close it needs to be to your boundary wall – in some rooms, the smaller Phantom 98dB model may suit better. All the same, Devialet makes mixing and matching between its active offerings very simple, as the app just takes care of it. Indeed, the audio role flexibility of the Phantom 108 is a real drawcard – you can use it as you need across multiple listening scenarios.

The Verdict

The Devialet Phantom Ultimate 108dB loudspeaker is more than just a pretty face, as it sounds as good as it looks. In absolute terms, it isn’t perfect, of course – no loudspeaker is –, yet it does so much right that it’s a captivating listen. The fact that it’s relatively modestly sized is all the more remarkable, given its all-round competence – for example, its low frequency performance far exceeds many premium-priced purpose-built hi-fi speakers.

Especially with the monitor function enabled, this is an exceptionally capable design that’s always engaging to listen to – its honest, natural tone and deftness of touch make every genre of music sound good. It doesn’t stop there, as it’s a highly capable home cinema performer too. All this, and good looks too! As such, if you’re after an extremely well-engineered, sonically adaptable and high-performing active loudspeaker with real aesthetic appeal, this is a no-brainer.

For more information visit Devialet