cost effective sound 'proofing'

Discussion in 'Home Theater Projects' started by dan_dj, Dec 19, 2003.

  1. dan_dj

    dan_dj Auditioning

    Joined:
    Nov 18, 2003
    Messages:
    14
    Likes Received:
    0
    I'm getting ready to start drywalling my theater and want to do some lower cost sound proofing to the ceiling. I was thinking about some fiberglass insulation between the joists and then double drywall. I'm not expecting it to be completely sound proof, but want to make it at least bearable upstairs. Should this do the trick?

    What is the best way to 'double' the drywall? Screw up the first layer, and then glue the second? Use screws for both layers? Should the seams be lined up or should I stagger them?

    Thanks.
     
  2. SteveLeach

    SteveLeach Stunt Coordinator

    Joined:
    Nov 19, 2003
    Messages:
    159
    Likes Received:
    0
    Here is a link to w web page that I have found to be very helpful, to me at least. I'm nearing the end of my design work so I've been trying to determine how much sound proofing I really need. http://www.soundproofing.org/infopages/soundwalls.html If you scroll down the page just a bit, you will see a comparison of different types of wall construction and what the resulting sound proofing value is. Keep in mind they are trying to sell their products, but I think the information is still valid.
    To save a bit of reading, when they mention calking. What they mean is that none of the drywall edges actually touch the floor, ceiling or in the corners. They leave about a .25" gap and then fill it with calk.

    To answer your question, for double dry walling you would want to stagger the seams, and personally I'd prefer screw attachment over gluing, but I don't really know if there is a significant acoustical difference.

    Hope this helps...
     
  3. Tom Kay

    Tom Kay Stunt Coordinator

    Joined:
    Mar 4, 2003
    Messages:
    86
    Likes Received:
    0
    Hi Dan

    You might want to consider using resilient channel, a 12 foot long flimsy sort of metal channel that "softly" mounts the drywall to the wall studs and joists. It "de-couples" the drywall from the studs, at least as far as acoustic enrgy and transmission are concerned.

    At first I was a tad intimidated by resilient channel because it looked too flimsy to screw into, and too weak to hold the weight of drywall. But after a did a little test section, these concerns proved to be non-existent. It was easy to use, and surprisingly strong.

    It's cheap to buy, easy to install, and if the studies by various acoustic labs are correct, effective in reducing the sound that makes it through walls and ceilings. I haven't finished my drywall, so I cannot comment on effectiveness yet.

    There are lots of sources of info on resilient channel, so have a look and maybe think about it. You have to add insulation in the empty spaces of walls and ceilings too, but it all works together.
    Cheers, Tom.
     
  4. ChrisWiggles

    ChrisWiggles Producer

    Joined:
    Aug 19, 2002
    Messages:
    4,791
    Likes Received:
    1
    Resiliant channel is more designed for stopping noise. Its affects on the acoustics in the room are unpredictable at best. You may obliterate bass performance inside your theater room.
     
  5. Derek Iverson

    Derek Iverson Stunt Coordinator

    Joined:
    Dec 10, 2002
    Messages:
    191
    Likes Received:
    0
    Really?
     
  6. Terry Montlick

    Terry Montlick Stunt Coordinator

    Joined:
    Jul 3, 2003
    Messages:
    120
    Likes Received:
    0


    I can't completely agree with this. Yes, resilient channel is for soundproofing. It has been pretty thoroughly studied, and will attenuate sound by as much as 10 STC points, depending on construction details. However, it has little effect on frequencies below around 100 Hz.

    Wall and ceiling acoustic characteristics are quite variable in these low frequencies, regardless of construction details. This is because wall and ceiling structures resonanate at between around 50-100 Hz. Such resonances may positively or negatively affect room acoustics, depending on existing room modes.

    Regards,
    Terry
     
  7. ChrisWiggles

    ChrisWiggles Producer

    Joined:
    Aug 19, 2002
    Messages:
    4,791
    Likes Received:
    1
    Well, I was just saying that it is designed from a "stopping noise" perspective, NOT an in-the-room acoustics perspective. If you do it right, I'm sure it can help your room sound, but I wouldn't go using it willy-nilly is all.
     

Share This Page