Thread: Sound insulation material

Good topic

I've been collecting 18x18 eggcrates from work, and I have a roll of Bituthane ready for when I finally get motivated to try something.

If you haven't built the box yet, don't build it square...the last time I did this we angled the walls to rediret the sound, and it helped immensely. We just swagged it, but you could probably get some good tips from the sound gurus on here....

Originally Posted by f1_hurricane

Dynamat...?

Really only works on reducing vibrations on metal, not reducing volume level.

Line both sides with Mass Loaded Vinyl. It is available in 1/16" through 3/4" thickness and is sold by the foot (I think the standard is 4' width). It's very heavy and is equivalent to the same thickness of soft lead sheet. The link is only one resource of many, so shop around.

I would use different thicknesses on either side (say 1/4" on the inside and 3/8" on the outside). This will broaden the isolation in terms of frequency.

If you wanted to get really serious, I would built 2 enclosures with one fitting over the other and a 3" air gap between them. Then line both with the vinyl. This is the most effective isolation where you have Mass-spring-Mass (air is the spring) and will give you the maximum amount of acoustical isolation.

Bake's suggestion about non-parallel surfaces is spot on, as this will keep resonant frequencies from "standing" in the enclosure (think of the old Pong video game) from continuous parallel reflections.

Once the enclosure is complete, seal all the intersects as completely as possible and if there is air intake/exhaust involved, either duct it with insulated ducting or face the opening away from the workspace. Even a small crack will undo all the noise isolation, so seal as completely as possible.