Our friend 秋山幸仁 (CEO/Owner) of Feastrex is finally pursuing his dream project... "Permendur" is an alloy in which iron and cobalt are mixed in a ratio of 1:1 and has the highest saturation magnetic flux density among the soft magnetic materials used in practice. It is used in magnetic field lenses, flat linear pulse motors for artificial hearts, etc. It is a very expensive material that can be called a precious metal. It is time to realize the concept of the "ultimate speaker" I once dreamed of. We will complete the Feastrex spherical magnetic circuit with the smallest magnetostriction in the world (0.25%) using the best material.