Spectator hall at racetracks and the like with loudspeakers

摘要

A spectator hall at racetracks includes a roof with an inner ceiling decreasing in height from the racetrack, an opening directed to the racetrack, a back wall, a number of seats arranged with increasing height from the racetrack, at least one loud speaker at the ceiling near the opening, and an invisible front wall covering the opening. The invisible front wall is made from a stable material like glass or acrylic polymer, and is mounted stiffly e g by stiffening bars.