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Soundproofing

I have an unfinished basement space, roughly 1000 sqft that I would like to convert to a TV and 2-channel listening room. The ceiling is open floor joists to to the first floor, any recommendations on soundproofing materials that I could use to rough finish between the joists. Floor/ceiling joists are 2x10's.

Thanks,
David
h2gastech
audiotroy's avatar
audiotroy
1,621 posts
 
h2 we have a lot of experience in this arena, we built a soundproof wall which was insanly effective 110db in room 85db outside of room and we bult the wall out of inexpensive materials.

The room and total project was featured on Rev Runs Rennovation 
season 2 Secret Cinema 

here is a grainy non hd copy of the programhttps://www.youtube.com/watch?v=EqrxRo0vmf4

https://www.flickr.com/photos/58319891@N08/albums/72157650239108910

https://www.flickr.com/photos/58319891@N08/albums/72157650233548529

We are trained theater designers please let us know if we can guide you in any way.

Dave and Troy
Audio Doctor NJ


folkfreak's avatar
folkfreak
1,149 posts
 
Amusingly @audiotroy illustrates how hard this is -- 85dB is the noise level of a busy road! While 25dB reduction is impressive even at a more normal 95dB in room then 70dB out of room is the level of a vacuum cleaner. If you are looking for silence (i.e. 50dB or less) then you need some 40dB+ of isolation which is really tough to achieve. Even in my heroically isolated room my wife can still tell which tracks I’m playing when she is in the room above (leaks via doors, windows, bass through ceiling etc). The dB of the audio leak through wouldn’t be measurable (ie. its in the background room noise) but the ear is incredibly sensitive.
audiotroy's avatar
audiotroy
1,621 posts
 
Actually Folk freak we got that sound leakage down heroically using layers of inexpensive materials done in a constrained layer damping system over the regular sheet rock, if we would have been able to build the wall out more we could have knocked it down very much more.

There is a huge difference between designing from scratch and retrofitting. Also the DIY Network is really cheap so our solution had to be as inexpensive as possible. 

We used cemment board, sheet rock, cemment board sandwich with green glue between all layers then we used a custom made absorbing diffusing panle the room sounded and looked great. 

Dave and Troy
Audio Doctor NJ
bdp24's avatar
bdp24
4,908 posts
 

The op is asking about soundproofing materials, and for the space between the joists and behind the new ceiling I would 2nd the suggestion of Roxul Safe ’n’ Sound (instead of the more common fiberglass insulation such as Corning 703). Using the ASC isolation "channeling", to which the new sheet rock is attached instead of to the studs, will decrease the transmission of sound to the room above.

Applying the ASC Wall Damp to that sheetrock, with a second layer of sr on top of that, will decrease the walls ability to do what drum heads do when struck with a drum stick---move in and out in the middle, which is how they create sound. Sheetrock actually flexes between the locations where it is screwed down, the middle moving in and out, creating noise. Folkfreaks’s room exhibiting none of that---the room was very quiet. Not just in it’s isolation from the outside world, but in the sense of it not creating any sound of its own. The quietest room I’ve ever not heard ;-) .

jburidan
672 posts
 
Roxul in walls and ceiling.
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