The Cabasse development protocol combines numerous measurements in an anechoic room, combining on-axis and 360° results. It guarantees a perfect control of both the directivity index and the total radiated power all along the frequency bandwidth to match the SCS principles. It is a key process, together with listening sessions, in the development of the cross-over boards. The slopes can vary from 6 to 24 dB per octave for an optimal acoustical phasing, taking into account the influence of the external shape of the enclosure to optimise the qualities of the co-axial drive-units.