Focal Sopra Νο1 White Β-Stock (Pair)

Since the beginning, we have always had a great interest in the magnetic circuit, an essential aspect of a speaker drive unit. The precision and detail of audio reproduction depends on the stability of the magnetic field. After having pushed back the limits in electromagnetic technology with the Grande Utopia EM and the Stella Utopia EM, our engineer discovered that the magnetic field varies regardless of its intensity. Indeed, it is not stable because it is modulated by three factors: the movement of the voice coil (Lenz's law), the current passing through it (Foucault current) and the frequency. Consequently, the voice coil, the moving part, is in the magnetic field which becomes too variable, and this leads to loss of precision.

The NIC technology lies in a Faraday ring whose dimensions, materials and positioning we were able to optimise to make the magnetic field be no longer affected by the position of the voice coil, by the amperage or the frequency of the current passing through it. This solution permits to control the magnetic field to decrease the effects of distortion and give the sound a very high-definition and an unprecedented dynamic.

The midrange register is no doubt the most complicated to control in a sound system.Thanks to the power of finite element analysis, our teams have revealed resonances which alter definition in the suspension which connects the cone to the basket

The solutions already known for increasing the damping properties of the suspension all result in an increase of the mass which consequently alters definition. The answer came from a technology used in earthquake-resistant skyscrapers and which is also used for the suspension on racing cars. This technology is called a " Tuned MAss Damper" : an additional mass oscillates in opposition to the resonance frequency to control it.

Our Tuned Mass Damper consists in simply two tubular rings on the suspension to avoid deformation of the cone without afflicting the dynamics. It reduces drastically the distortion and increase the definition.

Our Beryllium tweeter features an incredibly light and extremely rigid dome, that deliver a transparent and dynamic sound. Its main limitation comes from the compression of air in the cavity behind it, that create interference with the incredible definition. To overcome this, the ideal would be to have a nearly infinite volume. But the requirement for Sopra to be compact meant that as much of the cabinet as possible had to be used for the bass. We had to explore other options for loading the tweeter, which led us to come up with the IHL system.

The rear of the Beryllium tweeter is loaded via a small cavity which is connected to the exterior of the enclosure by a horn. whom inside is filled with a damping material. Sound waves from the rear of the tweeter are delicately and gradually absorbed. Its acoustic impedance approaches zero so that no resistance alters the movement of the dome. This reduces distortion by 30% and pushes definition to its maximum.