The effects of light equipment on the acoustic characteristics of a TV studio

Abstract

The characteristics of light equipment were investigated to understand their acoustic properties and effects in a television (TV) studio. The absorption coefficients were measured in a reverberation chamber with representative spotlights of 1 kW and 2 kW. Based on the absorption coefficients, laboratory tests using a 1:10 scale model of the test specimens were designed. The purpose of the experiment was to identify the absorption and scattering characteristics, including the coverage density, angle, and the presence/absence of barn doors. The results showed that the averaged absorption coefficients varied from 0.04 to 0.13, and the averaged scattering coefficients ranged from 035 to 0.81 as the coverage density varied from 5 to 16%, respectively. When the height position of the light was varied from 9 m to 3.5 m in the TV studio, it was found that the sound strength increased to 0.71 dB, and the clarity (C50) decreased to 0.30 dB. At a low height of 3.5 m, the reverberation time (T20) and the early decay time (EDT) increased for frequencies below 500 Hz and decreased for frequencies above 500 Hz. The use of light equipment increased the sound strength; however, the variation in both 120 and C50 was only slight. The standard deviation of the EDT and C50 in the space decreased by 16% and 43%, respectively.