Studi Eksperimental Perbandingan Knalpot Standar Dan Modifikasi Terhadap Kebisingan

This study aims to analyze and compare the noise levels produced by a standard muffler and a modified muffler on a two-stroke brush cutter engine. The research employed a quantitative experimental method by conducting direct tests on both types of mufflers. The independent variable was the type of muffler, namely the standard muffler and the modified muffler, while the dependent variable was the noise level measured in decibels (dB) using a Sound Level Meter. The tests were conducted at engine speeds of 3,000 RPM, 4,500 RPM, and 6,000 RPM, with measurements taken along the X, Y, and Z axes at several distances to determine the characteristics of noise propagation. The results showed that the modified muffler was able to reduce noise levels at all engine speed variations compared to the standard muffler. At 3,000 RPM, the noise level produced by the standard muffler at a distance of 0 cm ranged from 106.8 to 110.5 dB, whereas the modified muffler produced noise levels ranging from 92.2 to 95.2 dB, representing a reduction of approximately 13–18 dB. At 4,500 RPM, the standard muffler generated noise levels between 117.9 and 119.3 dB, while the modified muffler produced noise levels between 100.9 and 102.1 dB, corresponding to a reduction of approximately 17–18 dB. The test results also indicated that the greater the distance from the sound source, the lower the measured noise level. Overall, the modified muffler produced significantly lower noise levels than the standard muffler at nearly all measurement points.