The flagship of the new Privia line, the PX-850 has the advanced AiR sound set providing an additional level of realism including grand piano lid simulation and sympathetic resonance. The PX-850 has a dual 20w speaker system and a cabinet that opens providing a rich concert sound.The new PX-850 represents a significant step in the continuing evolution of the Privia digital piano line. A combination of a new keyboard action and a powerful new sound engine provide a new level of detail, nuance and expression for a superior grand piano experience in the lightweight and stylish design that Privia is known for. The PX-850 has 18 Instrument tones (5 are Piano), and 256 note polyphony. The PX-850 keys feature Damper Resonance, Hammer response and Sympathetic Resonance. A very special other feature is the Lid Simulation. You can choose (separate from what the actual PX-850 cabinet will do) whether you ant the lid on the Grand Piano open, closed, half or removed. The PX-350 has 1/4" audio outputs and USB-to-Device output so you can easily connect the PX-850 to recording and sound reinforcement equipment.