Magico A1 Loudspeaker Elliptical Crossover
In mathematics, an ellipse is a plane curve surrounding two focal points, a term also used by Magico to describe the symmetry of its crossover design. Its 'Elliptical Symmetry Crossover' (ESXO) boasts 'greatly accelerated roll-off slopes' – up to 4th-order in the 2kHz crossover used for the A1. However, high-order slopes typically mean more components, and increased losses, which is hardly ideal in a compact, sealed box enclosure of already limited sensitivity.
Magico has squared this circle, sorry, ellipse by placing a capacitor in series with the bass/midrange inductor [visible within the inset picture]. The value of the capacitor is precisely matched to the resonance frequency of the driver creating an electrical/acoustical filter that yields a 24dB/octave slope with only '12dB-worth' of components. Hence the custom Mundorf gold and oil capacitors made to Magico's specification...