Magico S3 MKII Loudspeakers M-CastThree way. Sealed box. Extruded aircraft grade aluminum cabinet a single piece monocoque shell produced at one of the only facilities in the world capable of extruding aluminum at this diameter, internally braced with bolts running through the half inch shell to stabilizing cross members. Magico builds sealed enclosures because sealed enclosures measure and behave correctly. No port tuning, no bass reflex coloration, no frequency at which the box