Abstract: According to one or more embodiments of the present disclosure, a riser may be operated by a method including repeatedly heating and cooling a riser between an operational temperature and a non-operational temperature. When the riser is heated from a non-operational temperature to an operational temperature, the riser undergoes thermal expansion. When the riser is cooled from an operational temperature to a non-operational temperature, the riser undergoes thermal contraction. The riser undergoes irreversible growth over repeated heating and cooling cycles, and the length of a lower section of an upper riser portion is sized to accommodate the irreversible growth from cycled thermal expansion of the riser.

Abstract: A device for enhancing enjoyment of electronically reproduced music including a chair with liquid-filled bladders coupled to transducers such as electromagnetic driver assemblies responsive to audio-frequency electrical signals. A diaphragm of elastic sheet material provides support for part of the bladder and part of the transducer. Bladders and transducers are located in the seat and back of the chair, and the transducers move the liquid in the bladders, so that movement of the liquid can be felt by a user sitting in the chair. The electrical signals are preferably filtered to pass only bass frequencies to the transducers.