Loudspeakers

There's more than a return to 'flower power' at work in Sonus faber's 'Camelia' driver concept where the edge of its midrange cone is both unclamped and has regular sections cut away. A conventional circular cone will necessarily have a singular circumferential resonance, a primary mode that's typically damped or otherwise modified by the compliant surround between the cone edge and the basket. Varying the path length across the radius of the cone by adopting this flower shape has the effect of distributing this one resonance into a series of lower-level modes that are damped by the inverted surround/suspension fixed underneath.

The concept is not new and is both described in a Patent held by Vifa-Speak A/S and used in Scan-Speak's Discovery driver series. Scan-Speak has developed the idea into what it calls 'Non Resonant Suspension Coupling', or NRSC, where it effects changes in mechanical impedance by altering the stiffness, mass and damping at the edge of the cone, creating additional reflections and scattering resonances. PM