Acoustical Influence of Lighting Equipment Arrangements in TV studios

Abstract

Various factors affecting space have been studied, and new research results are still being published. In the case of TV program production, more and more various forms and lighting techniques are introduced to maximize the visual effect. However, among many factors, research on lighting fixtures is still rare. Therefore, this study is to examine the effect on the acoustic environment of such lighting equipment. First, the characteristics of lighting 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 0.35 to 0.81 as the coverage density varied from 5 to 16%, respectively. With the coefficients obtained in a previous study, four TV studios in different size and usage were selected to investigate the influence of lighting fixtures through computer simulation. The simulations were categorized into three based on the change in type, coverage density, and height. The variations in the reverberation time due to the change of type were the highest variation of 8% in Hall A. In the case of coverage density, the reverberation time showed the highest variation in the order of Studio C, Hall A, Studio D and Hall B. The range of variation was 9% and 8% at Studio C and Hall A. For the height with the same density, Studio C exhibited the largest variation in reverberation time of 0.04 s at a density of 5%. Generally, the variation of Studio C and D was large compared with that of Hall A and Hall B. In the case of EDT, Studio C displayed a variation of higher than 15%. In the case of C80, only Studio C exhibited a difference of higher than 1 dB for all coverage densities. When the variations in height and density are considered, the highest variation was found in studio C. The difference in reverberation time between the heights and densities of (4 m and 5%) and (8 m and 15%), respectively, was 0.9 s, corresponding to a variation of approximately 12%. In addition, C80 values of Studio C and Studio D between the heights and densities of (4 m and 5%) and (8 m and 15 %) were 1.63 dB and 1.27 dB, respectively. In conclusion, compared with the hall type multipurpose studio with audience seats, the shoebox type studio without audience seats was more affected by the lighting equipment. In terms of studio type, the small-size studio showed the greater variation. In the case of hall type, the relatively long reverberation hall showed greater variation in reverberation. When both height and density are considered, the variation range widened. Therefore, where both installation area and height of lighting equipment for each program production change frequently, designing of TV studio must be considered the effect of lighting equipment more significantly.