How can you measure the effectivity of a soundproof material?Please help!
This is a challenging question. Effectivity is a very subjective term. Think about the soundproofing in an automobile...or the soundproofing in a radio broadcasting booth, On a small scale if you desire to measure the direct effectiveness of different materials, build a small box (probably two feet in each direction of 3/4 inch plywood...thinner material will be deflected by the sound inside...wire a small speaker to one wall of the box and line the box with the desired test material. Place a small decibel meter outside the box away from the speaker wall at a close distance from the box and using a suitable radio, or hi fi system, play sound through the speaker. The readings on the decibel meter will give a direct correlation between the different types of material used to line the inside walls of the box. This test box could be used to give information about the frequency range effectiveness of the different tested materials. If you have access to an oscilloscope, you might get some interesting information about the acoustic properties of various materials used in soundproofing. Enjoy the experimenting