Product characteristics were to include precision and transparency of the sound. Moghaddam, acting as chief designer, set out to find solutions to engineering problems he saw as inherent in the belt-driven suspended sub-chassis turntable design of Edgar Villchur, where the sub-chassis and tonearm are free to rotate. Moghaddam believed that the design generated undesirable torsional modes. One such torsional mode is said to be caused by "groove drag" – dynamic forces exerted by the stylus on the record as it tracked it. Moghaddam chose to attenuate the torsion by mounting the turntable-drive motor casing on its own bearing. The motor, mounted separately and tethered to a spring, is allowed limited rotation about its own axis; because the load varied with groove modulations, the increases in drag would thus be dampened by the spring-loaded motor, and the platter acceleration mitigated. In the words of Tufan Hashemi, Roksan Audio's managing director: "We argued that using a suspended or floating surface to support a record could not allow it to be accurately read, as the record itself would be floating. We said that the record surface should remain stationary and solid but in complete isolation from the rest of the deck, and our design provided a very stable base for isolating a record without suspending it." Like the LP12, the Xerxes has a two-piece platter–sub-platter configuration on which sits a thin felt mat. And while the LP12's platters are made of mazak, the Xerxes' platters are of aluminium. The outer platter is rigid and peripherally weighted. However, the Roksan's outer platter weighs less than half of that of the LP12, to reduce load on the main bearing, yet is able to achieve a greater inertia because of its weight distribution. A second challenge was how to overcome the rotation of the suspended parts – the sub-chassis, platter, arm and cartridge – relative to the motor. This was done by re-imagining a suspension that had less freedom of lateral movement relative to the drive motor. The Xerxes uses a relatively light medium-density fibreboard (MDF) top board on which the bearing and tonearm assemblies are mounted. Firm rubber "Blobs" mounted on the bottom board (along with the motor assembly) support yet decouple from the top board. Aesthetically, the two boards are encased by a wooden surround fixed to the base board with screws.