Optimum choice
The surface area of a loudspeaker cabinet is infinitely greater than that of the driver diaphragms, so it can radiate sound at a level close to that of the diaphragms, which is colored and distorted by the resonances of the cabinet structure. This alters reproduction and blurs the sound image. To prevent such "interference", it's essential that the cabinet is as inert as possible, and not emissive. At Focal, we use MDF (Medium Density Fiber) to achieve this inertia. This material may seem "low tech" compared to other materials used by some competitors, but MDF has intrinsic advantages that make it an optimal choice for cabinet construction.
Firstly, it is dense and sufficiently rigid (when used in great thickness for massive front panels) to counteract the acceleration of the moving parts under the effect of magnetic force. When a cone is propelled by the voice coil, an opposing force acts in reaction on the loudspeaker frame. This reaction force is one of the main causes of vibration in the cabinet structure, and must be perfectly controlled. A front panel of very high mass is required, but stiffeners must also be judiciously positioned to control resonances from other cabinet walls. A cabinet made of a very rigid material can be just as bad as one that is insufficiently rigid, as it pushes resonances into a higher frequency zone where the ear is more sensitive.
Secondly, MDF is similar to a sandwich structure, mainly in thickness, with the faces on either side of the panel denser than the core. This contributes to rigidity, but also provides natural internal damping to help absorb any stray vibrations. For Utopia and Sopra, the fronts are made of thick MDF panels laminated together to multiply the sandwich effect.
Finally, MDF can be easily machined with numerical controls to obtain curved shapes. The first acoustic advantage is that such shapes avoid direct reflections by progressively diffracting the sound wave around the cabinet, thus eliminating secondary emissions caused by direct reflections from sharp angles. Secondly, from a structural point of view, a curved shape offers greater intrinsic rigidity than a flat panel.
Focal products using this technology
Discover other Focal technologies
REMOTE AMPLIFIER IN CURRENT MODE
The most transparent and natural
Since main monitors are frequently soffit-mounted, these require external electronics for this application. Focal engineers have therefore developed an amplification system combining a class H with a current mode. By controlling the current (instead of the voltage), it is possible to directly control the force submitted to the membrane and eliminate any unwanted artefacts. Combined with analogue filtering and exceptional drivers, this amplification achieves the lowest THD ever measured in an anechoic chamber.
"M" profile Béryllium Tweeter
Rigidity and Purity
Patented by Focal, the pure beryllium ‘M’ profile tweeter combines rigidity, lightness and damping for exceptional high-frequency reproduction. The ‘M’ membrane is the result of many years of research and expertise. Made in a single piece, it improves sound dispersion, reduces distortion and ensures optimum power handling.
Infinite Horn Loading
High-definition sound
For the Beryllium tweeter to deliver all its finesse, it would need an almost infinite volume. Sopra's need for compactness meant that the maximum volume of the cabinet had to be used for the bass. Exploring new ways of loading the tweeter led us to imagine the IHL infinite-load horn. The IHL (Infinite Horn Loading) system enables the Beryllium tweeter to be loaded while respecting the compactness of the loudspeaker. The rear wave is gently and progressively absorbed to avoid distortion. The result is maximum definition.
JOIN THE COMMUNITY
Get a sneak preview of the latest audio innovations and new products from Focal and Naim by subscribing to our exclusive newsletters. Be among the first to benefit from privileged information delivered straight to your inbox.
Newsletter
New products and limited editions
Invitations to exclusive events
Benefit from special offers