The spider has been neglected by many speaker brands, considering it as the "k[mm/N]" which allow to adjust Fs[Hz] according to the existing moving mass. The strength of conventional spider isn't linear, and its variation gives rise to Fs[Hz] variation according to cone excursion. As a consequence, the bass response depends on sound pressure. - We have developed an exclusive corrugation profile which keep constant Cms[mm/N] on the full excursion. The non-linearity measurements and the listening session show the merits of our innovation