5Focus Ring™ and Power Flower™

User manual Utopia Be line

Being hidden away magnetic circuits are seldom considered. However the energy that they give is essential to the quality of reproduction. Focal-JMlab is always asso- ciated with investing in powerful arrays. And with the new Utopia line, the com- pany wanted to apply its latest innovations.

“Focus Ring™” - a patent for the magnetic circuit of the tweeter.

An intense magnetic field is of the utmost importance for good tweeter performance and the TGU conceived for large Utopia into 95 was a key point in the development of the Utopia line. Selecting a magnet that combines high power with small dimensions narrows the choice of magnet material to Neodymium. However the small dimensions required - and the need for a light coil with a narrow air gap leads to intense heating of the magnet. A problem then occurs due to a characteristic of Neodymium: its low “Curie Point”. The magnetisation saturation decreases as the temperature rises and will cancel at a certain temperature, called the “Curie Point” (Tc). For a ferrite, Tc is equal to 450 °C and, for a Neodymium Nd2Fe14B magnet Tc is equal to 319 °C. Which means, should the magnet reach its Tc, the magnetic stru cture will loose its magnetism bringing irreversible damage to its output and an audible loss of dynamics and definition. Since the design of the TGU in 95, the evolution of the home cinema arena has imposed new constraints with regards to power handling. In high fidelity musical performances very little energy is demanded at high frequencies. However, with the special sound effects of home cinema new rules in terms of power handling are created, with the subsequent effect on magnet temperatures.

Handling these new demands was a key rational in the design process of the new tweeter Beryllium Utopia (TBe), which adopted a key new concept called “Focus Ring™” - Focal-JMlab patent pending. The material used in the magnet is Samarium-Cobalt Sm2Co17, which is more expensive and slightly less powerful than Neodymium. However it offers a major advantage in that it pushes the “Curie Point” (Tc) back to 825 °C, avoiding any chance of temperature related magnetic losses. However to obtain a magnetic field of 2 Tesla, as in the TGU, doping of the magnetic circuit is required by using a Neodymium ring to surround the Samarium magnet, thereby concentrating the magnetic flux and reaching the target field. In addition, with the ring being mounted away from the coil it is not affected by temperature increases and gives the tweeter exceptional stability

“Power Flower™” - a patent for a high precision mid-range

The new mid-range 165mm driver has also directly benefited from Focal-JMlab’s experience of developing Cone “W” technology since 1995. A new membrane has been developed for use with a new a 40mm coil and the optimisation of its rigidity has allowed a “single skin” cone to be formed, which is perfectly controlled over a one octave range from 1 500-3 000Hz - essential to the setting of the OPC filter. The phase plug is no longer effective and is replaced by a large aluminium focus plug. Any risk of coloration is eliminated and directivity is optimal. The link with the tweeter can be made seemless and the impusle response of the combined tweeter/mid-range is ideal.

This mechanical optimization of the drivers eliminates the source of various sonic problems and in addition offers the guarantee of great manufacturing consistency. The magnetic circuit must be of high precision with very low losses. But the utilisation of large pole parts generates a problem of flatness. The bonding beetween pole piece and magnet is not consistent and generate magnetic losses. The “multiferrites”, technology, first initiated by Focal-JMlab more than twenty years ago for the company’s top woofer , also brings an unexpected solution to the mid range of the Beryllium Utopia line. The new - patent pending - “Power Flower™”, uses seven powerful, but small diameter ferrites laid out concentrically around the core. Bonding beetween pole piece and ferrites is very accurate and cancel any variations due to small deviation in the flat surface. Moreover the polar parts are machined in the shape of flower, whose petals match the shape of the ferrites, and to stop magnetic escapes between the bottom and top of the field. Finally, this arrangement satisfies a double requirement: high power output and perfect control of the magnetic discharge. Magnetic loses in production are thus very small and in combination with the tight tolerances of the Cone “W” manufacturing, the “Power Flower™”* design has given exceptional accuracy to the 165mm mid range unit. The very small tolerances ensure a perfect reproduction of any performances, particularly in the highly sensitive mid-range, guaranteeing the strict tonal balance of the speaker.

"Curie Point" of different magnets. Only Samarium-Cobalt and Alnico offer a large safety area when temperature increases.

"Focus Ring™" : Neodynium ring concentrates the magnetic flux to 2T. The central magnet uses Samarium-Cobalt to offer high stability with temperature.

The shape optimisation and the use of multiferrites reduce consistently the magnetic field losses.

*The concept of “Power Flower™” also offers two additional advantages of excellent coiling for the coil and offers two another advantages, an excellent cooling of the reel and a full back de compression.

The new mid-range “Power Flower™”. A great manufacturing consistency provides an exceptionnal accuracy to this 165mm, guaranteeing the strict tonal balance of the speaker.

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Focal Utopia Beryllium Line 5Focus Ring and Power Flower, Focus Ring a patent for the magnetic circuit of the tweeter
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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.
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