1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

new construction questions

Discussion in 'Home Cinema Building DIY' started by daver96, May 29, 2003.

  1. daver96

    daver96
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Howdy. I am going to start construction in a couple of months on my new house. My media room (interior dimensions) are 19' (front/back) and 16'11" (sides) with a base ceiling height of 9' (the plate height of the house).

    I know that these room dimensions are not optimized golden-rule-wise, but there are still a few items I can play with.
    1) should I step the ceiling up to 10' (this would require soffits - a box ceiling if you will - since the front wall is an outside wall, and other posts have indicated that soffits add a lot of unwanted reverberation and reflections). I'm trying to make the room sound as good as possible, bearing in mind that the other dimensions cannot be changed, and I'm curious if a 10' boxed ceiling would sound better than a 9' standard ceiling with the other room dimensions taken into account.

    2) I am trying to figure out to what extent I should soundproof the room on a tight budget, since I like to play movies loud (who in their right mind doesn't?). One of the side walls has the kitchen and dining room on the other side of it, with the family room on the other side of the kitchen/dining room (all other sides of the room aren't adjacent to areas where I'm concerned with noise transmission). My current plan has an offset 2x6 wall (see this diagram) between the media room and the kitchen/dining room, with the other walls being standard 2x4 construction(see this diagram). On all walls and the ceiling, I am planning on using a single layer of sheetrock/gypsum board, with ASC's WallDamp between the sheetrock and the studs on the interior of the media room (all 4 walls plus the ceiling) as well as on both sides of the wall that is shared between the media room and the kitchen/dining room. The shared 2x6 wall will also have QuietZone wall batts in it, and I plan to treat all the joints/cracks with acoustic sealant. I have calculated that the cost of the walldamp and the sealant is about $1200 extra. Is this going to sufficiently mute the low frequencies so that I don't wake up my wife? :-D Would adding an additional layer of sheetrock (like this) make that much difference?

    3) Do putting sound batts in the walls make the room itself sound any better, or do I just need those in the walls that I am concerned about sound transmitting through? I suppose the same question applies for the WallDamp.

    Any insights would be GREATLY appreciated.
     
  2. Gary Lightfoot

    Gary Lightfoot
    Well-known Member

    Joined:
    Apr 6, 2001
    Messages:
    12,145
    Products Owned:
    0
    Products Wanted:
    1
    Trophy Points:
    136
    Location:
    Surrey. UK.
    Ratings:
    +1,956
    A good method that works is to build a 4x2 wall (600mm centers) one inch in front of the existing wall, and fill it with 4ins of good Rockwool insulating batts, and then finish with two layers of plasterboard.

    The batts help stop any in-wall resonance and reduces the higher frequencies from traveling through. Bass can only be stopped with mass, and two layers of plasterboard will help do that.

    Sealing all edges with high modular silicon rubber or similar prevents any sound traveling through any gaps that may be there - where air can go, so can sound, so sealing is a good idea.

    What you have shown above reiterates the normal 4x2 method, and shows staggered studs so that you don't lose as much as 6ins of room space.

    I don't know how good the products featured there are, but the basic idea is sound, so should work.

    There is more on this subject over at www.avsforum.com, and Dennis Erskine designs and builds cinema rooms for a living, so anything he has to sayis worth noting. Use the search for his name and soundproofing in the screen forum for more info.

    Unless you build a room within a room to completely isolate the inner room, you will stil get bass traveling through walls merely by the fact that it is touching them. It will be reduced by the wall being built in front of the existing wall, but the floor and ceiling will be able to transmit sounds, albeit less so than if the walls were touching.

    So, I would say to go with the final drawing using two layers of plasterboard. Two layers help build a stiffer wall, and glueing the two layers together using something like 'no more nails' will help with the stiffening. A 'loose' wall can act like a bass trap and reduce the bass in the room.

    HTH

    Gary.
     
  3. ReTrO

    ReTrO
    Active Member

    Joined:
    Jul 12, 2000
    Messages:
    3,498
    Products Owned:
    0
    Products Wanted:
    2
    Trophy Points:
    71
    Location:
    High Wycombe, Bucks, UK
    Ratings:
    +59
    There's is some really good reading on building a soundproof studio (and thus a good soundproof HC/HT room) on the Auralex website.

    See here: http://www.acoustics101.com/
     

Share This Page

Loading...