Monday, November 17, 2014

Soudproofing a Basement

Keep it simple and avoid overpriced materials. A few have ben mentioned already.

You will need clips and channels on the bottom of the joists to decouple that drywall. If that drywall is directly attached (coupled) your low frequency bass isolation will suffer a great deal. Do not use resilient channel. Very problematic.

Use standard R19 fiberglass. The other insulations mentioned will not be an improvement over cheap fiberglass. Lab data defines this for us.

Use standard drywall. You cannot beat the mass associated with standard $8 a sheet 5/8"drywall. Use two layers. Forget about MLV. It's $$ and drywall weighs a lot more and is cheap

Damp that drywall with a quality damping compound.

Avoid recessed lighting and other unnecessary penetrations.

That's a start.
Ted White

The Soundproofing Company

Bill, Ed, and Daniel,

A great way to soundproof the ceiling with or without the use of resilient channels (RC-1) is to staple up a material called mass loaded vinyl (MLV). I feel this is a much better material to use than the Firestone APP 170. Now granted it is a little more costly, but is is a 100% vinyl material impregnated with barium salts and silicas, which give it the same properties (soundproofing wise) as lead sheeting.
Bill was right about the cost of lead lined drywall, however, you can always purchase the lead foil (sheeting) and glue it with industrial adhesive or contact cement directly to the back of the drywall, and you have virtually the same thing at less than half the price. The vinyl is as good a soundproofer as the lead, though the lead is a little bit better at blocking low frequency noises, (bass sounds etc.)
If you don't have the room to float using the resilient channels, because the duct work is too far beneath the floor joists, you could always use the (MLV) stapled to the joists and  seam taped at the seams, and then simply drywall over the (MLV) with a layer of 5/8" fire code rock. If the main concern is keeping the sound down stairs, then this is the ticket. Please feel free to give me a call if you need further information. Thanks Gents.

Bob Orther
Super Soundproofing Sales/Technical Associate.
Ph: (760) 749-7049    FAX: (760) 749-6384
For orders only (888) 942-7723

Forget that stuff. Low mass, high cost.

You can build a very well isolated room at a reasonable cost if you follow the following basic, tried and true methodology.

#1 Decouple the framing. This can be done with staggered stud or double stud walls. To decouple the ceiling, consider clips&channel. Resilient Channel (RC-1) attempts to decouple, however there is no industry standard or specification for its construction, so I’d be concerned about using it.

#2 Install absorption in the cavities. This means standard fiberglass R13 in the walls, R19 in the ceiling. Know that there is no data that supports that any other insulation (including the “acoustic” labeled, and recycled cotton) works better. Also, foam (open or closed cell) is superior for thermal, but distinctly worse for acoustic. Use the cheapest fiberglass you can find.

#3 Add mass. Nothing better than standard 5/8” TypeX. Great mass at 70+ pounds a board, and cheap at $7 a sheet. Use two layers. Only mud and tape the final layer.

#4 Consider damping these drywall panels with one of several field-applied damping compounds. Some work better than others, and independent lab data shows you get what you pay for here.

After that, you’d turn your attention to the ventilation, lights and doors. All of these are flanking paths for sound to get out of the formidable room you just built. They can be dealt with fairly easily, but you’ll want to design this in. 
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