I am in the process of finishing my basement and have been researching the best methods for reducing sound transfer between the basement and main floor of our home, a ranch. Since my daughters' bedrooms are nearly above the theater, my primary goal is to keep the sound in the basement, although sound coming into the theater will need to be addressed as well. I understand that the best method for reducing sound transfer would be to build a room within a room. Unfortunately, this will simply not work with my current layout.



When complete, I should have a theater that is approximately 16’ X 24’. Here are my other key measurements:



Ceiling on N side of beam (concrete to joist): 7’2”

Ceiling on S side of beam, S of ductwork: 6’11”

Ceiling just S of beam (width of beam + ductwork is 45”): 6’5”



*If this requires additional explanation, let me know.



Since I am unable to build a room within a room I am considering the use of resilient channel, or furring strips. Additionally, I may add a second layer of drywall, although I am concerned about doing that with the already low ceilings. I am looking for any input you have regarding the use of resilient channel, especially when coupled with sound isolation clips (see links at bottom of post).



Aurulex offers resilient channel at fairly steep prices. Home Depot offers resilient channel at quite modest prices. The two products look different from each other-is there any difference other than price? Is there another brand I should consider? The sound isolation clips seem to run about $5 each. My math leads me to believe that I would need approximately 70 of them (ceiling only), so I am wondering if I would be better off using them, or some sort of a sound blocking material instead.



I am interested in any opinions on this project!



David



http://www.soundproofing.org/sales/SSP.htm

http://www.acousticalsolutions.com/products/isolation/clips.asp

http://www.soundisolationcompany.com/Sound-Isolation-Clips.php

http://www.kineticsnoise.com/arch/isomax/index.html

A couple of observations here. The product from Sound Proofing, and Sound Isolation are the Kinetics ISOmax isolation clips. The Acoustical Solutions is the PACInternational (www.pac-intl.com) style clip. All of this are designed to be used with HAT Channel NOT resilient channel. Resilient Channel is an entirely different product with much less low frequency attenuation than either of the other two products.

Next, if all you are planning to do, is the ceiling, don't bother. You need to do the ceiling and the walls or all that will happen is the sound will flank around the ceiling. If you're tight on headroom and room width/depth, then your better choice will be two layers of drywall with green glue between the layers.

Don't even think about Mass Loaded Vinyl (MLV) products which are marketed under various trade names such as AcoustiBlok, etc. The mechanism used by MLV is mass and MLV has less mass than 5/8" drywall at a far higher cost.

Its been stated by one or more of the forum experts that resiliaint channel is counter productive at isolating the low frequencies. Clips, however, are recomended. If height is a concern, ISO MAX clips are usually the option. Not sure if clips will out perform double drywall or double drywall + GG.

Be wary of sound flanking. Isolation is only as good as the weakest link.

EDIT - speak of the devil, Dennis was the expert I was thinking of, though others have said the same. His advice is more concrete than mine.