Properties of a drive unit membrane

6		The "W"	™	cone

User manual Utopia Be line

For more than 15 years the composite cone sandwich technology is a Focal-JMlab exclusivity. The “W” process, ﬁrst initiated in 1995 with the Grande Utopia, provides now a true optimisation of the frequency response.

Three parameters are of prime importance: mass, internal damping and stiffness.

•Stiffness allows the cone to behave as a piston over a wide range of frequencies, especially important at bass frequencies for low distortion.

•Low mass delivers maximum acceleration on transients for the best reproduction of fine detail.

•Internal Damping damps out any ringing or vibrations in the cone structure that

would otherwise color the sound.	Analysis using laser interferometry allows the optimization of the “W” cones
	in terms of rigidity/damping/mass.

Materials

•Paper a light material, though not very rigid, but with reasonable internal damping. Sound often suffers from a “cardboard” coloration.

•Polypropylene/Plastics a material relatively heavy, but with good internal damping properties. Not especially stiff and the sound tends to lack detail and precision.

•A simple woven aramid fibres cone (not a sandwich type construction) uses a resin to seal the cone and bring about the rigidity required, but this tends to lead to a dull plastiky coloration.

The sandwich structure Focal-JMlab

During the mid 1980s, a new type of cone was developed and patented by Focal-JMlab which com- bined low mass, stiffness and high internal damping; the “Poly-K sandwich”.

Using woven aramid fibres tissue skins and a core of hollow microspheres of glass mixed with a resin, this structure exhibited extremely high rigidity and low mass.

The damping could be controlled by the properties of the core.

Since this original construction, the process has been refined and developed to produce a new generation of aramid fibres sandwich. The major advance in the construction of this cone is the use of a special structural foam in place of the resin + microballs. This foam is used primarily in the Aerospace industry; no other foam offers the same high ratio of stiffness/mass.

The name “W” is derived from Verre-Verre(Verre = Glass). The “W” cone uses two very fine tissues of woven glass that are lighter and thinner than aramid fibres.

In addition, the molecular bond between the foam and the glass tissue is far superior to that of the aramid fibres. This results in a cone structure which is mechanically more stable and with superior stiffness. This construction allows us to further optimize the transmission speed of the sound wave in the cone. This new construction process allows the amount of internal damping in the structure to be very accurately controlled by varying the thickness of the foam: the thicker the foam,

the higher the damping factor.

The relationship between the thickness of the glass tissues and the foam core allows us to finely optimize the cone structure depending on the particular application and the frequency area

to reproduce.

The “W” cone produces an extremely transparent and neutral sound free from coloration and distortions normally associated with loudspeakers.

Its only limitation, the price; more than ten times the price of a quality paper cone.

Comparison of the index of rigidity in flexure (expressed in N.mm).

The performance of the “W” cones significantly betters that of other materials for the same mass. In addition, internal damping is also superior.

The hand-made manufacturing of the "W" cone. Our industrial process is patented.

The ‘W’ structure, a central core of foam covered by skins of glass tissue.

Utopia Beryllium Line specifications

The Focal Utopia Beryllium Line represents the pinnacle of headphone technology, combining cutting-edge materials with sophisticated design to deliver an unparalleled listening experience. Renowned for their audio fidelity, these headphones have become a benchmark in the high-end audio market, attracting audiophiles and casual listeners alike.

At the heart of the Utopia series is the innovative beryllium driver. This unique material has been chosen for its exceptional rigidity and lightweight properties, which allow for precise sound reproduction across a wide frequency range. The beryllium dome used in the drivers is lighter than traditional materials like plastic or aluminum, contributing to a rapid response and minimal distortion, even at high volumes.

Another hallmark of the Utopia Beryllium Line is its open-back design, which enhances the listening experience by creating a natural and immersive soundstage. This design allows air and sound to flow freely, resulting in a more open and airy sound. Listeners are treated to an expansive audio landscape, with instruments and vocals feeling as if they are placed in a three-dimensional space.

The Utopia headphones also incorporate Focal's "M" shape dome technology, which optimally shapes the driver to provide an extended frequency response. This technology ensures that the headphones deliver rich bass, detailed mids, and sparkling highs. The frequency response ranges from a low of 5 Hz to a high of 50 kHz, allowing listeners to experience the full spectrum of sound.

Comfort is another critical aspect of the Utopia design. The headphones feature soft memory foam earpads and a lightweight structure that ensures long listening sessions can be enjoyed without discomfort. The headband is made from high-quality materials, contributing to both the aesthetic appeal and the longevity of the product.

Further, the Utopia Beryllium Line boasts a striking aesthetic, with a luxurious look that includes genuine leather and an elegant, modern finish. The combination of form and function makes these headphones not just a tool for listening, but a statement piece for any audio enthusiast.

In summary, the Focal Utopia Beryllium Line stands out for its revolutionary use of beryllium in driver technology, open-back design, and commitment to comfort and aesthetics. These features come together to create a transcendent auditory experience, setting a high standard for what audiophiles can expect from premium headphones. Whether for casual listening or critical listening sessions, the Utopia Beryllium Line is engineered to impress.

Focal Utopia Beryllium Line user manual Properties of a drive unit membrane, Materials

Models: Utopia Beryllium Line

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