Balanced drive motor structure for optimal drive force symmetry, resulting in greatly reduced even-order harmonic distortion Rigid air-dried paper cone to ensure piston motion even at high levels for lower distortion Low-loss suspension (high Qm) for improved reproduction of details and dynamics Rigid steel chassis with extensive venting for reduced air flow speed, lowering audible distortion Vented center pole with dual flares for decreased noise level at large cone excursions Large motor structure for enhanced control and power handling