Especially new are the woofers and midrange drivers with patented flat cones. They consist of a special mixture of TPX and polypropylene thermoplastics, which are additionally stiffened by a defined amount of glass fibre rods. In the middle of the flat membrane, an inverse fabric dome optimises the vibration behaviour. The large "Concert Grand" version is equipped with three 18 mm woofers with these cones, the smaller "Baby Grand" with two 15 mm woofers. A 15 cm flat cone is used as the mid-bass driver in both models and a silk dome in the tweeter range. The ported cabinets, which are strutted and divided into chambers, are available with real wood veneer in rosewood or cherry or with black or white piano lacquer. A die-cast aluminum base is included in the scope of delivery. Both loudspeakers are specified with an impedance of 4 ohms.