Amplified music and variable acoustics—Shorter reverberation times at low frequencies

Abstract

A survey from 2010 among professional musicians and sound engineers revealed that a long reverberation time at low frequencies in halls during concerts of reinforced music such as pop and rock, is a common cause for an unacceptable sounding event. Lower frequency sounds are, within the genre of popular music, rhythmically very active and loud, and a long reverberation leads to a situation where the various notes and sounds including vocals cannot be clearly distinguished. This reverberant bass sound rumble often partially masks even the direct higher pitched sounds. In an article from 2011, it was hypothesized that mid- and high-frequency sound is seldom a reason for lack of clarity and definition due to a 6 times higher absorption by audience compared to low frequencies, and a higher directivity of speakers at these frequencies. A survey from December 2016 among 25 professional musicians and sound engineers confirms that a longer reverberation at higher frequencies in the empty hall can advantageously be projected and that the 125 Hz octave band is probably the single most important band to control. Details from this survey and results regarding the author’s most recent developments in the field of variable and mobile absorption in favor of both amplified and classical musical genres are presented.