Overview
Ten years after upending hi-fi conventions, Devialet rewrites its own myth with the Phantom Ultimate 108 dB. This French wireless speaker combines 1100 watts of power, 108 decibels of sound pressure, and a frequency response that plunges down to 14 Hz—technical performance that defies the laws of physics for an 11-kilogram object. Powered by a new generation of drivers and an NXP iMX8 processor, this ovoid sphere turns every listening session into a sensory phenomenon where sound is felt as much as it’s heard.
Physical design and build: when form follows function
The Phantom Ultimate 108 dB retains the spherical silhouette that has become Devialet’s signature, but there’s nothing arbitrary about this shape. The ACE geometry (Active Cospherical Engine) enables omnidirectional sound dispersion while minimizing diffraction. With dimensions of 246 mm wide, 342 mm deep, and 255 mm high, the speaker occupies a surprisingly compact volume given its acoustic capabilities.
The bi-injected composite structure combines multiple materials in a sophisticated construction. The outer ABS layer offers a soft-touch finish while ensuring the required rigidity. Beneath it, a layer of glass fiber–reinforced polycarbonate adds density and inertia to absorb vibrations. At the core, an injected aluminum spine serves as the backbone. Redesigned for this generation, this pivotal piece serves multiple functions: it mechanically supports drivers subjected to considerable forces, dissipates heat generated by the electronics, and helps eliminate parasitic resonances.
The new-generation drivers mark a significant evolution. The aluminum-dome tweeter benefits from a redesigned grille with a 13% increase in open area, the result of six months of research. The aluminum-dome midrange adopts a coaxial configuration with the tweeter for optimal phase coherence. The two ABS-dome woofers are mounted in a push-push (back-to-back) configuration, a layout that cancels mechanical vibrations while doubling acoustic efficiency. The absence of a dust cap on the woofers, visible on this generation, required a complete overhaul of the suspension and magnetic motor to achieve a slimmer profile without compromising excursion.
Three finishes are available. Light Pearl dresses the speaker in matte pearlescent white with chromed metal plates, creating a subtle interplay with light. Deep Forest wraps the sphere in a deep, almost black green, accentuating its monolithic character. The Opéra de Paris edition, adorned with genuine 22-carat gold leaf, elevates the technical object into a luxury piece.
Embedded technologies: a technological arsenal in the service of emotion
The Phantom Ultimate 108 dB concentrates seven proprietary technologies protected by four new patents. The new-generation ADH remains the cornerstone of the system. This hybrid amplification combines on the same circuit an analog class A amplifier—guardian of linearity and musicality—with four class D digital amplifiers that deliver power and efficiency. Real-time processing has been optimized to maintain perfect synchronization even at extreme frequencies, reaching 35 kHz with THD+N distortion of just 0.0005%.
SAM (Speaker Active Matching) continuously analyzes the audio signal and adapts in real time the voltage sent to each driver. For every sample of the signal, the system precisely calculates the voltage needed for the reproduced sound pressure to be the exact image of the original signal. This active correction maintains phase and amplitude with surgical precision across the entire bandwidth, particularly critical in the low end where diaphragms make excursions of several centimeters.
HBI (Heart Bass Implosion) is the most visually spectacular innovation. This suite of multiphysics innovations allows the side woofers to pulse with an amplitude visible to the naked eye, creating a hypnotic show synchronized with the music. The convex woofer diaphragms increase internal sound pressure, enabling extension down to 14 Hz—a frequency so low it’s felt physically more than heard. This technology turns the speaker into a true pressure-wave machine that literally passes through the listener.
AVL (Adaptive Volume Level), inherited from the Devialet Dione soundbar, brings real-time dynamic equalization. The system continuously analyzes content to subtly adjust the frequency response according to listening volume, preserving tonal balance even at low levels. This ensures that the subtle details of a whispered dialogue remain as intelligible as the most intense moments of an action soundtrack.
Magic Wire DAC optimizes the path from the digital signal to the converters, minimizing jitter and electromagnetic interference. The Devialet ASIC (Application-Specific Integrated Circuit) integrates the entire signal processing chain on a dedicated chip, enabling minimal latency and optimized energy consumption.
Connectivity and operating system: intelligence serving simplicity
The brain of the Phantom Ultimate 108 dB is an NXP iMX8 processor, a multicore ARM Cortex chip designed for demanding multimedia applications. This processor runs DOS 3 (Devialet Operating System), the third generation of Devialet’s in-house OS. This software platform manages all audio streams, streaming protocols, and synchronization between multiple speakers with imperceptible latency.
Wireless connectivity reaches a new level with Wi‑Fi 6 (802.11ax) in 2×2 MIMO configuration on the 2.4 and 5 GHz bands. This standard provides greater stability, reduced latency, and the ability to handle multiple simultaneous streams without degradation. Bluetooth 5.3 with A2DP and AVRCP profiles supports SBC and AAC codecs. The absence of high-definition codecs like aptX or LDAC is a limitation for Bluetooth sources, but network protocols more than make up for it.
The streaming protocol arsenal covers all modern use cases. AirPlay lets Apple users cast directly from their devices, limited to 16-bit/44.1 kHz. Google Cast goes up to 24-bit/96 kHz for Android users. Spotify Connect and Tidal Connect offer native integration of these services. UPnP support enables playback from any DLNA server on the local network. Roon Ready (RAAT) certification will delight audiophiles using this sophisticated music management system.
Wired connectivity is pared down to the essentials: a Gigabit RJ45 Ethernet port for a stable network connection and a TOSLINK optical input accepting up to 24-bit/192 kHz. The lack of analog RCA ports or an HDMI ARC input limits integration options in some systems, and the previously offered Arch hub is not compatible with this generation.
User interface and app: fingertip control
The physical interface on the top of the shell includes four capacitive touch sensors arranged in a cross. The volume + and – controls allow quick adjustments, the play/pause button controls playback, and a fourth button activates Bluetooth pairing. A central LED indicator communicates the speaker’s status: off, blinking during startup, solid white when operating. This minimalist interface favors visual elegance while providing essential controls.
The Devialet app, completely redesigned for this generation, becomes the nerve center of the experience. The six-band equalizer allows fine-tuning of the sound signature to suit preferences or room acoustics. Three preconfigured audio modes automatically adapt processing: Music Mode preserves neutrality to respect artistic intent, Movie Mode broadens the soundstage and accentuates effects, and Podcast Mode optimizes vocal intelligibility.
Stereo configuration transforms two Phantom Ultimate 108 dB units into a compact hi-fi system. Pairing is done directly in the app, with synchronization between speakers handled by the Devialet DOS 3 Sync protocol at 96 kHz/24-bit. The additional 3 dB of acoustic gain—and above all the creation of a true stereo image—elevates the mono experience.
Multiroom mode lets you create independent or synchronized listening zones. Each Phantom can play different content or join a group for synchronized playback throughout the home. Adjustable A/V latency ensures perfect lip-sync when watching movies. Night mode intelligently attenuates low frequencies to keep the peace with neighbors without distorting tonal balance.
The Devialet Remote, sold separately, offers precise physical control via a premium rotary dial. A proximity sensor on the speaker automatically detects the remote to facilitate pairing. In a stereo setup, a single remote controls both speakers.
Measured acoustic performance: the numbers behind the sensation
The maximum sound pressure of 108 dB SPL measured at 1 meter under 1 kHz puts the Phantom Ultimate on par with a chainsaw in sheer loudness. This ability to generate considerable sound pressure in a 6-liter volume defies acoustic conventions. The frequency response extends from 14 Hz to 35 kHz (±6 dB), covering well beyond the human audible spectrum. The plunge to 14 Hz deserves particular attention: at this infrasonic frequency, sound becomes pure vibration, creating a physical sensation of chest compression.
The noise floor measured at 0 dB SPL at 1 meter attests to meticulous electronic design, enabling micro-detail retrieval even at low volume. Total harmonic distortion plus noise (THD+N) of 0.0005% rivals the most expensive hi-fi electronics. 32-bit/96 kHz digital processing preserves the resolution of high-definition sources throughout the signal chain.
Directivity remains controlled up to around 8 kHz thanks to the coaxial tweeter/midrange design. Beyond that, the polar pattern gradually narrows—a phenomenon inherent to any single-bodied speaker. This characteristic influences optimal placement: a position between 45 and 90 cm from the floor maximizes impact, while a minimum clearance of 30 cm from the wall allows low frequencies to develop naturally.
Technical specifications
Audio performance
- Amplifier power: 1100 W
- Maximum sound pressure: 108 dB SPL @ 1 m
- Frequency response: 14 Hz – 35 kHz (±6 dB)
- Noise floor: 0 dB SPL @ 1 m
- Digital processing: 32-bit / 96 kHz DSP
- Audio inputs: up to 24-bit / 192 kHz
Drivers
- 1 aluminum dome tweeter (new generation)
- 1 aluminum dome midrange (new generation)
- 2 ABS dome woofers (new generation)
Proprietary technologies
- ADH (analog/digital hybrid amplification) – new generation
- SAM (speaker active matching)
- HBI (heart bass implosion)
- AVL (active volume level)
- DAC Magic Wire
- Devialet ASIC
- Devialet Operating System (DOS 3)
Connectivity and streaming
- Wi‑Fi: Wi‑Fi 6 (802.11a/b/g/n/ac/ax, 2×2 MIMO, 2.4 and 5 GHz)
- Ethernet: RJ45 Gigabit (100/1000 Mbps)
- Inter-speaker connection: Devialet DOS 3 Sync. Protocol (96 kHz / 24-bit)
- Optical input: 1x TOSLINK
- Bluetooth: 5.3 (A2DP and AVRCP profiles, SBC and AAC codecs)
- Streaming compatibility: AirPlay, Google Cast, Spotify Connect, Tidal Connect, UPnP, Roon Ready (RAAT)
Design and materials
- Configurations: mono/stereo (paired)
- Construction: bi-injected composite enclosure (ABS + glass fiber reinforced polycarbonate, die-cast aluminum central core)
Dimensions and weight
- Speaker: 246 × 342 × 255 mm (W × D × H)
- Weight: 11.1 kg (speaker only) – 12.3 kg (packaging)
Power supply
- Voltage: 100–240 V~, 50/60 Hz
- Power consumption: off < 0.5 W | standby < 2 W
Box contents
- Devialet Phantom Ultimate 108 dB speaker
- Power cable
- Documentation
Frequently Asked Questions
Does the Phantom Ultimate 108 dB replace a full home theater system?
A single Phantom Ultimate delivers remarkable power and bass extension for movies but is limited by its monophonic nature. Two speakers in a stereo setup create an impressive soundstage for a 2.0 system, particularly effective in rooms up to 40 m². The absence of a dedicated center channel and surround effects is still noticeable for home cinema purists. The app’s Movie Mode nevertheless optimizes playback for video content.
What’s the real difference between the Phantom Ultimate 108 dB and the 98 dB version?
Beyond the 10 dB difference in maximum sound pressure, the differences are substantial. The 108 dB reaches down to 14 Hz versus 18 Hz for the 98 dB, offering an extra octave in the extreme low end. It also extends higher to 35 kHz versus 25 kHz. Power jumps from 400 W to 1100 W, and crucially, the acoustic architecture differs: the 108 dB adopts a three-way system with coaxial configuration versus two-way for the 98 dB. Weight and dimensions increase significantly (11.1 kg versus 4.3 kg).
How does the visible movement of the side woofers work?
The spectacular pulsing diaphragms result from HBI technology. The two back-to-back woofers operate in opposite phase: when one pushes, the other pulls. This push-push configuration doubles efficiency while canceling mechanical vibrations. Excursion can reach several centimeters at low frequencies, creating a hypnotic visual effect perfectly synchronized with the music. This motion isn’t a gimmick but the physical manifestation of the generated sound pressure.
Can you use multiple Phantoms from different generations together?
The multiroom system supports all Phantom generations (I, II, and Ultimate), regardless of power. However, to create a stereo pair, both speakers must be identical in model and power. This backward compatibility lets you expand your setup over time without rendering previous models obsolete.
- Eco-contribution included in the sale price.
- Manufacturer reference: KW898
























