Acoustics for Amplified Music and a New, Variable Acoustics Technology

Surveys among professional musicians and sound engineers reveal that a long reverberation time at low frequencies in halls during concerts of reinforced music is a common cause for an unacceptable sounding event. Midand high-frequency sound is seldom a reason for lack of clarity and definition due to a up to 6 times higher absorption by audience compared to low frequencies, and a higher directivity of loudspeakers at these frequencies. A new technology of inflatable, thin plastic membranes presents a solution to this challenge of needed low-frequency control. It is equally suitable for multipurpose halls that need to adjust their acoustics by the push of a button and for halls and arenas that only occasionally present amplified music and need to be treated just for the event. This paper presents the authors’ research as well as the technology showing applications in dissimilarly sized venues, including before/after and off/on measurements of reverberation time versus frequency.