Loudness control in a small volume Recital Hall

Abstract

Mississippi State University’s new music building features a 173-seat Lecture Hall that also serves as a recital hall. The limited volume presents an acoustical challenge to accommodate a variety of uses—most concerning are the louder and larger ensembles with up to 25 musicians and 50 singers sharing the stage. Due to project-specific constraints, the 24 foot stage-to-ceiling height and the 60,000 cubic foot volume are less than the early design-phase recommendations for the expected uses, which raises concerns about loudness buildup and inability to generate desired reverberation. Our goal is to implement variable loudness control systems that provide a useful reverberation range with good clarity across different settings. We identify and justify four loudness control strategies—maintain early, supportive reflections; shape the room to form patterns of sustained sound in areas with adjustable absorption; reduce high-frequency sustain in areas near audiences; avoid flutter echoes—and illustrate how those strategies were integrated into the architectural design through room shaping, fixed wall treatments, and deployable curtains and banners. We discuss subjective and instrumented observations about the loudness (measured in Sound Strength G), reverberation time (measured in T30), clarity (measured in Clarity Index C80), and overall character of the room response.