QUALITATIVE ANALYSIS OF THE SAWDUST COMPOSED PERFORMANCE AS SOUND ATENUATION MATERIAL
The research is carried out to describe a characteristic of the sawdust composed as sound atenuation material. The purposeof the research a) to describe the sound atenuation and reflection coefficients of material composed, and b) to know materialperformance in the interval effective frequency. The six samples were made of the Pterocarpus Indica sawdust, gypsum, phenolformaldehide,and transparent resin, then those were formed in cylinder with diameter 10 cm. This research used: a) TwoMicrophone Impedance Tube B&K 4206, b) B&K 2718, c) B&K Pulse Multianalyzer , d) one set computer Pentium IV with 512MB, HD 40 GB, Pulse Program v. 6.0. The results were: a) the coefficient absorption for three composed with 0.57 – 0.67; and ithas an interval effective frequency between 600 Hz – 1.4 MHz. Three composities were made of the sawdust of PterocarpusIndica more than Gypsum, because phenol and resin weren’t significant effected. Two composities in lower quality and its hascoefficient absorption next to 0.4 and one composite has not characteristic. The coefficient reflection of two composite between0.58 – 0.68 (fair-good), and it has an interval effective frequency 700 Hz – 1.4 kHz. It can be concluded that sound atenuationperformance of composed, effective with ratio Gypsum and Pteracorpus Indica 5 : 6 with thickness 1.6 cm.