Almost from its introduction, the in-wall loudspeaker has been an audio stepchild. Unfortunately, this reputation is well deserved, as poorly conceived and poorly executed designs continue to flood the market in a feeding frenzy to cash in on the most obvious and popular selling points of the in-wall concept: invisibility and the freeing up of precious domestic real estate.

Viking Electronics

But eliminating the space invaders that take up valuable floor space comes at a hidden cost: sound quality suffers significantly.

A comprehensive study of currently available in-wall models led DALI engineers to the conclusion that the shortcomings of the in-wall loudspeaker lay not in the concept itself, but only in the slipshod manner in which it has been realised so far.

Therefore, DALI set out to create in-wall loudspeakers that would be fully the sonic equal of any comparably priced conventional design, but with the added convenience and discretion that only built-in loudspeakers can offer.

Drawing heavily on technological innovations from our acclaimed high end Euphonia Series, modified to meet the strict demands of the rapidly expanding installation market, we devised the Euphonia IWS 3 Phantom, a 2½-way speaker with a 6½” woofer/midrange and a Hybrid Tweeter Module in a sealed enclosure.

The DALI Euphonia Phantom in-wall loudspeaker targets the critical listener who seeks a compact, non-intrusive solution that maintains the design integrity of his living space at no compromise in audio performance.

Euphonia Phantom lives up to its design brief: to set a new standard for audio quality in the in-wall category.

DALI will launch several in-wall speakers in each of our current ranges. All DALI in-wall speakers will have the suffix name Phantom.

All In All, It’s Not Just Another Brick In The Wall

In undertaking the daunting challenge of developing an in-wall loudspeaker, it is necessary to attain a full understanding of the essential differences between a floor-standing speaker and an in-wall model.

As a rule of thumb, the floor-standing speaker will generate more reflections in a room and offer lower sensitivity in comparison with an in-wall speaker.

The floor-standing speaker essentially radiates sound in a 360° angle, dispersing acoustical energy across a far larger area of the room. An in-wall has the dual advantages of reduced room reflections and higher sensitivity, as it only disperses acoustical energy in a 180° angle. In fact, an in-wall design is, theoretically speaking in several aspects, a “better” defined acoustical solution than a conventional floor-standing loudspeaker.

However, there are crucial trade-off’s that must be addressed before rushing to exploit the obvious advantages of an in-wall solution. Specifically, there are two major obstacles that must be overcome. With an in-wall, the listening position is fixed, a condition that must be understood and accepted by the user.

The second and major issue is the acoustic properties of the mounting site itself. Most walls that would be deemed suitable for built-in loudspeakers have low rigidity, making speaker installation a bit like suspending the speaker from a wire. An unstable platform will limit the speaker’s sonic potential.

A key unknown in this equation is the wall cavity, which may be filled with different kinds of insulation materials or with nothing at all. This is a highly unpredictable situation from an acoustical point of view and can have tremendous impact on the performance of the speaker.

In typical in-wall designs with no rear enclosure, acoustical compromises must be made in the drive units to compensate for possible wall cavity scenarios. These compromises are inevitably detrimental to sound quality.

This places the in-wall speaker basically at the mercy of the flexible wall in which it is mounted and of the materials (if any) in the wall cavity.

These crucial problems have been addressed and eliminated in the design of the Euphonia Phantom.

The Phantom Menace

As described above, the main problem with an in-wall speaker is not the speaker, but the wall in which it is framed and the cavity behind it.

A Stable Platform

A wall can vary tremendously in stiffness and therefore exert significant influence on audio performance. DALI addresses the problem of a “soft” wall by making the Euphonia Phantom itself quite heavy and rigid, a massive 7 kilos (16 lbs.). The sheer mass of the speaker acts as a solid base even when mounted in a very “soft” wall.

An enclosure that forms a rock-steady platform for the motion of the drive unit in an in-wall speaker is critical. With anything less, the platform may move with the drive unit, thereby degrading sound quality.

The Wall Cavity

In a typical in-wall speaker with an open back, the material in the cavity wall will exert major influence on the sound. Because it is impossible to predict what, if any, materials will be present in the cavity wall, DALI has eliminated this great unknown by employing an airtight sealed enclosure for the Euphonia Phantom.

A sealed enclosure ensures full control over the acoustics of the speaker, eliminating the sonic influence of any materials – or absence of materials – in the cavity wall.

There are at least five critical requirements for an in-wall loudspeaker enclosure:

* It must be compact to fit the wall cavity.
* The enclosure must have as much interior volume as possible to preserve audio quality.
* The enclosure must be as non-resonant as possible.
* The enclosure should be heavy.
* The enclosure should be fireproof.

The Euphonia series incorporates a special vibration-absorbing cabinet material HornFlex® to eliminate cabinet resonances and vibrations and maintain the integrity of the audio signal. In theory, this material would be a perfect acoustical solution for the Euphonia Phantom, but is in fact not feasible due to space limitations in the cavity wall, as well as the issues of interior volume and fireproofing.

Instead, we developed a rear enclosure with virtually identical damping abilities that also meets all five requirements.

Die-Cast Aluminium Enclosure

The die-cast aluminium enclosure of the Euphonia Phantom In-wall speaker is rigid and strong, even when cast very thin.

This is an ideal solution, as it allows the restricted space behind the loudspeaker to be employed to increase the captive interior air volume behind the drive unit, instead of being filled with thick-walled enclosure material.

Aluminium has the unfortunate disadvantage that it can resonate in the audible frequency range if not properly damped.

To prevent resonance in the aluminium casing, the enclosure is cast with bracing ribs and the inside has a layer of compact bituminous damping material.

The front baffle is firmly attached to the aluminium enclosure. Together they form a structure that cancels vibrations and resonances.

The rear enclosure fits a standard 4-inch deep wall. Its restricted depth also contributes to the preservation of audio quality, as the cabinet is too small for standing waves to build up.

The rigidness of the aluminium, the cast bracing ribs, the interior vibration absorbing layer, the MDF front baffle combine with the aluminium rear enclosure and the compact dimensions of the Euphonia Phantom form a unique sonically damped solution, perfect for a high performance in-wall speaker.

Driving Miss Phantom

The Euphonia IWS 3 Phantom employs a 6½” bass/midrange and a Hybrid Tweeter Module consisting of a 29 mm soft dome tweeter and a 10 x 55 mm ribbon tweeter in a sealed enclosure.

6½” – When Size and Space Matter

The 6½” bass/midrange unit is custom-made for the Euphonia series. In order to achieve our sound design principles of “Time Coherence” and “3D Audio,” the cone must be very fast and very lightweight.

To achieve these goals, we developed a type of paper cone that contains unusually long wood fibres in a carefully measured proportion.

The shape of the cone is optimised to effectively transform the electrical signal at the voice coil into corresponding air motion and to provide wide dispersion – another DALI sound design principle.

Paper has a low density and is able to move very fast – at frequencies up to 10 kHz, but because of its low mass, vibrations in an ordinary paper cone will have an undesirable characteristic sound. In Euphonia Phantom, these vibrations are eliminated through the use of wood fibres and double coating of the cone.

The wood fibres distribute energy in all directions due to their random alignment in the cone, thereby eliminating the material’s “own sound”.

The cone, spider and surround are mounted in a rigid, ventilated die-cast aluminium chassis with no cavity underneath the spider and a vent in the pole piece (yoke) to prevent compression behind the dust cap. These measures prevent compression and improve free airflow.

The magnet system is optimised for minimal distortion. In order to achieve low distortion, the magnetic field (flux density) must be absolutely stable and independent of voice coil motion.

In a traditional magnet design, maximizing flux in the voice coil gap is a high priority. Such designs typically use a thick pole plate in order to increase the conductivity of the magnetic circuit.

In the Euphonia Phantom bass/midrange driver, we have focused on stabilizing the magnetic flux in order to optimise the quality, not just the quantity of flux.

By using very powerful magnet and a very thin pole plate, we drive the pole plate iron into the “saturation” area, where flux density is stabilized at a precisely defined level.

This saturation principle is analogous to Class A power amplifiers where output current flows from a saturated bias circuit, stabilising the operating parameters for the amplifier’s electrical components substantially.

It is commonly known that this design principle ensures lower audible distortion, a more “relaxed” sound and higher subjective output power than indicated by the specifications.

Similar advantages are offered by the Phantom’s “Class A” magnet principle and, as in the world of amplifiers, the result is significantly better audible performance than a first glance at the specs would indicate.

We Are The Hybrid, Resistance Is Futile

The Hybrid Tweeter Module in the Euphonia IWS 3 Phantom consists of a 29 mm-oversized soft dome tweeter and a 10 x 55 mm ribbon tweeter.

The Hybrid Tweeter Module is in our view the ideal high frequency solution. Both the soft dome and the ribbon tweeter are artifact-free (e.g. resonances and high Q peaks within their working range).

They both deliver extremely smooth, wide horizontal dispersion, one of DALI’s sound design trademarks.

Dome, Sweet Dome

The 29 mm oversized soft dome tweeter is especially designed for DALI. The tweeter is designed with a neodymium magnet structure with a rear chamber, a coated silk dome and a very long voice coil that allows undistorted reproduction of the high frequencies.

The magnet system has three powerful neodymium magnets that provide a strong and stable magnet system. Copper rings are utilized to further enhance performance and to short circuit eddy currents in the magnet system, as well as optimise the impedance characteristics.

The rear plate of the magnet system is ventilated to allow acoustical passage to the rear chamber of the tweeter for a significantly lowered resonance frequency of 750 Hz. The rear chamber itself is damped to suppress undesirable resonances.

The geometry of the soft dome tweeter is designed for optimum dispersion characteristics and well-controlled rigidity. Rigidity is increased using a special coating on the silk dome. The coating is applied in a multi-step process in order to obtain the desired characteristics without sacrificing dynamics.

All this ensures an unparalleled impulse response and energy-time-frequency characteristics.

The voice coil is wound on a perforated aluminium form (for low compression) with extra large winding width for long-throw excursion. This ensures that compression is minimised when the soft dome tweeter handles high peak signals and enhances power handling.

The soft dome tweeter is rolled in carefully around 3 kHz and is allowed to operate up to its natural high frequency limit well beyond 20 kHz without being rolled off in the crossover. Together, these features ensure smooth, stable performance – enhancing the overall quality of high frequency reproduction.

Deserves a Ribbon

As in the ultra high end DALI MegaLine, a ribbon tweeter is used in DALI Euphonia IWS 3 Phantom. The ribbon tweeter has a broad frequency band and superb dispersion of the highest frequencies. The ribbon tweeter is gently rolled in above 10 kHz, reaching full contribution from 13 kHz to well beyond 30 kHz. The ribbon tweeter is a master in the horizontal dispersion of high frequencies and is a superb partner for the soft dome tweeter’s unique ability to reproduce frequencies from 3 kHz upwards.

Six rectangular magnets and aluminium conductors control and activate the low-mass, ultra-thin diaphragm. The magnets are positioned three in front of the diaphragm and three behind to ensure a perfectly symmetrical magnetic field.

The magnets in front of the diaphragm are powerful, compact neodymium magnets, while the rear magnets are larger ferrite types for improved heat dissipation.

To obtain perfect dispersion characteristics and optimum energy transfer in the high frequencies, a special acoustical lens guides the energy from the diaphragm into the room.

Numerous simulations and experiments have been conducted to carefully optimise the pattern and geometry of the acoustical lens.

Low Frequency Level Adjustment

Because the in-wall speaker is mounted in a reflecting boundary of a wall or ceiling, the low frequency sound pressure level is increased.

The level of low frequencies will vary depending on the distance from the loudspeaker to the next reflecting boundary such as a corner where the walls meet.

Different wall and ceiling types will absorb more or less of the bass energy, which means that the listener must have the option of controlling the level of the low frequencies.

To compensate for these variations, Euphonia Phantom incorporates a front-panel switch to adjust the bass level.

The switch has two settings “NORMAL” and “ENHANCED”. The low frequency level adjustment in the two settings has been carefully tuned based on a number of simulations and experiments in different rooms and loudspeaker setups.

The “NORMAL” setting is recommended when the loudspeaker is mounted in a sturdy wall close to a sidewall. This setting compensates for the possible increase of the lower frequencies when a speaker is close to a reflecting boundary.

The ENHANCED setting is recommended if the speaker is either some distance away from sidewalls or if the ceiling absorbs a substantial portion of the low frequency energy. The “ENHANCED” setting will boost the level of the lower frequencies and thereby compensate for a room that absorbs some low frequency energy.

Low frequency adjustment is also beneficial when the Euphonia IWS 3 Phantoms is used in conjunction with a subwoofer. Typically, it is possible to achieve better integration between the subwoofer and the Euphonia Phantoms by experimenting with the low frequency level switch and the various settings of the subwoofer (phase, level, crossover frequency).

Crossover to Better Sound

The heart of any loudspeaker is the crossover. The Euphonia Phantom crossover is made with high quality components that are point-to-point hardwired and glued/strapped on a stable vibration absorbing base plate. By hardwiring point-to-point, the connection between crossover components is optimised and loss is reduced to an absolute minimum.

The inductors in the crossover are wound from pure copper. The inductors are carefully positioned and angled, to minimise any interaction of the electrical fields.

The capacitors are high quality polypropylene foil capacitors and large-surface bipolar capacitors. The capacitors have been carefully selected for excellent sonic performance in collaboration with the inductors and the rest of the loudspeaker design.

A single power resistor is used in the crossover. Wire-wound and based in an aluminium house, it is screw-mounted to the base plate to eliminate any risk of mechanical noise.

We custom design all our drivers to achieve precisely the desired electrical and acoustical characteristics. When we design the crossover, we can concentrate on the actual time alignment and frequency separation to each driver. There is no need to use the crossover to correct or compensate for any unwanted behaviour from any of the drivers. The result is a small and simple crossover with a minimum of filtering – ensuring pristine signal transfer to the drivers.


The gold-plated spring loaded connectors are developed especially for Euphonia Phantom. The loudspeaker cable is secured by spring-lock mechanisms that ensure constant tension on the cable for a long-lasting, reliable electrical connection. This was chosen, as the accessibility to the cavity wall is not as “easy” as a floor standing. The connectors are bolted directly to the rear enclosure of the loudspeaker.

When designing the binding post we paid special attention to the conductivity. The connector leading the electrical signal to the crossover is made in one piece, contra to traditional design.

This ensures that there is no more conducting parts than absolutely needed – ensuring minimum electrical loss.

Out of Sight, Out of Mind

For easy and fast installation, Euphonia Phantom can be mounted in a wall or ceiling without any disassembling of the loudspeaker/bracket/bezel. We simply use six doglegs on the rear of the enclosure. Once the screws are turned clockwise, the “doglegs” will automatically swing into place and secure the speaker.

Two crash eyebolt fixings are found on the rear of the Euphonia Phantom. A steel wire should be attached to the eyebolts and to a solid building component part. In the event of earthquake, fire or mechanical breakdown of building parts, the wire will hold the Euphonia Phantom safely, avoiding the risk of human injury.

The Euphonia Phantom includes a painting mask to be used if the owner wishes to paint the speaker to match the home interior/decor. To spray paint the loudspeaker, the painting mask is simply placed over the drivers and the baffle.

Another useful accessory is the cutout template delivered with the Euphonia Phantom. The cutout template makes it easy to preview the loudspeaker positioning before the Phantoms are mounted. The template also helps mark the wall for the cutout of the hole in the wall.

When it all comes together

The DALI sound design principle of “Wide Dispersion” is a perfect match for an in-wall speaker. The in-wall speaker is fixed to a certain position in the room and the wide linear dispersion of the Euphonia Phantom ensures not only that the sweet spot is larger, but also that a large area in front of the in-wall speakers is covered with linear frequency response. In other words the DALI in-wall delivers better, more accurate sound in a larger area of the room.

The sound from an in-wall speaker generates fewer reflections than a typical floor-standing loudspeaker. The listener will experience fewer reflections and less time smear, resulting in clear, accurate sound. But these inherent advantages can only be fully appreciated if the in-wall speaker has been designed to resist the influence of a “soft” wall and the cavity wall.

DALI Euphonia Phantom is designed to deliver exceptional sound quality independent of the characteristics of the wall and wall cavity in which it is mounted.

Phantom of the Opera, Jazz, Pop, Rock, Techno, Symphony, Folk, Blues…

While the perception of sound is profoundly subjective and can ultimately only be judged individually, we will attempt to describe the Euphonia IWS 3 Phantom sound as objectively as possible. The Euphonia Phantom offers a convincing, high-resolution sonic illusion with great transparency and weight regardless of musical style. Voices and instruments are accurately positioned within the soundstage in a richly detailed sonic image. However please let the Euphonia Phantom convince you personally.


* Low-resonance aluminium sealed enclosure
* Unique drivers designed and developed by DALI
* Low-compression rigid die-cast aluminium driver chassis
* Low-loss rubber suspension
* Ribbon and soft dome Hybrid Tweeter Module
* 29 mm neodymium soft dome tweeter
* 10 x 55 mm ribbon tweeter
* Long excursion woofer basket
* Stable flux magnet
* Chamfered pole vent
* Paper/wood Fiber Cones – low mass, high rigidity and non-resonant
* Amplifier-friendly linear impedance
* Handmade hardwired point-to-point crossover
* Safety eyebolt for secure fixing
* Painting mask and cut-out template included
* Handcrafted in Denmark

IWS 3 Phantom
In-Wall Speaker

Frequency range +/- 3dB (Hz)

58 – 28.000 (enhanced)
64 – 28.000 (normal)

Sensitivity (2.83 V/1m)(dB)


Nominal impedance W


Maximum SPL (dB)


Crossover frequencies (Hz)

3.100 (15.000)

Bass reflex tuning frequency (Hz)

Enclosure type




Recommended amp. Power (Watts)

50 – 200


High frequency drivers

1 x 29 mm soft dome
1 x 10 x 55 mm ribbon

Midrange drivers

Low frequency drivers

1 x 6½”


Low Frequency Level

Connection inputs


Dimensions (HxWxD) (cm)

47.7 x 28.5 x 11.0

Dimensions (HxWxD) (inches)

18.78 x 11.22 x 4.33

Weight (kg/lb)



White (NCS S0502-Y)