Dedicated home theater room

Discussion in 'Archived Threads 2001-2004' started by Brian_Dickson, Jan 22, 2002.

  1. Brian_Dickson

    Brian_Dickson Auditioning

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    I am moving into a house with a garage that is pretty much useless, so I had the great idea of turning it into a dedicated home theater room. I don't have the best equipment at this time but I plan to start building. I figured the best way to start would be to have a room for the sole purpose of making the veiwing and listening experience the best that it can. Now, my question to you is, is there a difference in the insulation and drywall that I use in an acoustical sense? Should I put up wallpaper or paint? Carpet or cement? Should I suspend my speakers from the ceiling or put them on stands? I am very new to this but want to learn so any suggestions will help, thanks![​IMG]
     
  2. Dan Hitchman

    Dan Hitchman Cinematographer

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    First off, welcome!

    Second, what are the dimensions of the garage you plan to use? H, W, and L

    If you plan to sound isolate the room from the rest of the house it depends on how much space in the room you can afford to give up since some plans call for a staggered stud wall approach or double layered dry wall with staggered seams. You should also seal the room with acoustic caulk so there is no sound leakage (also seal the outlets after they are installed). Sound waves act like light waves. If there is a tiny hole somewhere for the sound to escape, it will. Plus a heavy door with sound proof seals would help too. Since part of the garage is probably on an outside wall(s) and the ceiling is more than likely not insulated at all you do need proper R valued pink insulation for heat and cold (also helps with trapping sound transmissions).

    Then, after the new room dimensions are created, you can determine with software and some help how to best acoustically treat the room.

    I wouldn't suspend speakers from the ceiling.

    Industrial grade carpeting (you might spill drinks and food and it needs to be wear resistant) and a thick, quality pad will help with slap echoes. Probably will have to water seal the cement floor first (as if you were fully finishing a cement basement).

    I'd run about three dedicated 20 amp lines (for audio equipment, amps, and projector) from the breaker box to the room and two dedicated 15 amp lines for lighting, electric curtains, etc. and if you want to plug in a vaccum cleaner or lap top, etc. (all five breakers on the same side/leg of the fuse box to minimize ground loops). You also have to plan for a quiet HVAC system for heating, cooling, and cold air returns (some use the dumby column approach on the sides and back of the theater to hide duct work and surround speakers, and hide the staples from putting up acoustic fabric paneling).

    If you decide to take out the drywall that's there you could run PVC pipe channels (with strings) so you can easily upgrade or add wiring and interconnects without having to punch holes in any new drywall you add.

    That's some of the basics to be considering. There is more to discuss, but I didn't want to overwhelm you at first.

    Dan
     
  3. Brian_Dickson

    Brian_Dickson Auditioning

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    Dan-

    Thank you for the reply! I am not sure what the dimensions are at this time because we haven't moved in yet, but I am going this weekend so I will be sure to measure. The terms "staggered stud wall" and "double layered dry wall" are a little foreign to me. I will have to do some research on those. The walls don't have any dry wall on them right now and it has the normal 2x4 vertical boards with horizontal supports staggered throughout.

    Is acoustic caulk different than regualar caulk? I don't think I've ever seen it.

    What is the software that will help with the acoustics?

    Again thanks for helping me get on the right path, I was a little lost on what to look for first!
     
  4. Chad Anson

    Chad Anson Second Unit

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    Hi Brian!
    Good to see a fellow Austinite! I am in the planning stage for my theater. I'm building my theater into what is essentially a walk-out basement (fairly rare in Texas). Before I start construction, I've got to deal with a foundation drainage issue.
    There is a lot of information to digest. I suggest reading through ALL of the threads in this and other forums (AVSFORUM.COM has a good theater construction forum, but tends to be a little hypertechnical). I also recommend that you create shortcuts to threads that you think are useful (w/ Internet Explorer right click on the page and select "Create Shortcut" and it will put it on your desktop) and save them all to a folder.
    Following are a few universal guidelines that I've observed:
    * using a room-within-a-room (building a set of walls/ceiling that is contained within an existing room) approach with double drywall on the inside room is desirable for acoustic isolation among other reasons (one layer of 5/8" and one layer of 1/2"). Insulation should be placed between the inner and outer walls... the consensus seems to be that the type doesn't matter much.
    * If you don't want to go with the room-in-a-room approach, I'd definitely still go with the double layer of drywall.
    * w/ acoustic treatments, sound should be absorbed below ear level and reflected above ear level (TheaterShield Plus and its successor is often used for absorption, drywall or drywall covered with batting and fabric is often used for a reflective surface)
    * the screen wall should have sound absorbing material all the way up
    * it makes sense to run two or three dedicated electrical circuits, 1 to the projector, and 1 or 2 to the equipment closet. 20amps is probably the best value (the wire is only slightly larger than 15amp and not so large as to be unwieldy)
    * if you have two rows of seating, the second row should be 10" or higher than the first for stadium seating effect... I'm going to go with at least 12". Look for the threads on how to build the risers
    * if you are going to use a proscenium (stage in front of the screen), there are several threads on how to build it (filling with sand, creating the radius, etc.)
    * if you are going to build columns, add them AFTER you've completely drywalled the room.
    Specifics such as room dimensions, seating distance, how much sound absorption to use, etc. are much more difficult to take into account in a general sense.
    Acoustic caulk is different than regular caulk. I haven't tried to find it locally. It is readily available via mail order.
    I think that you should ask yourself a few questions that will really help your design process:
    (?) What type of display do you want? Projector (this is what I'm going with) or RPTV? This will dictate things such as screen size, minimum distance from screen to seats, wiring requirements, etc.
    (?) How much and what type of seating do you want? Couches, theater seats, etc. I found a source for awesome refurbished theater seats for like $60 per seat.
    (?) Do you want your equipment in a built-in rack, an equipment room, a stand-alone rack, etc.?
    Where are you moving? My wife and I just moved from SW Austin out to Lakeway.
    Good luck and feel free to email me at [email protected]
     
  5. Dan Hitchman

    Dan Hitchman Cinematographer

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    Bang vs. buck for home theater video has got to be a widescreen digital front projector. Buy towards the end of construction so as to get one with DVI and or FireWire digital video inputs and compatibility for the copy protection schemes Hollywood wants for HDTV (by then they should be on the market).

    With a front projector you have to determine the projector's throw distance for the size and aspect ratio of screen you want (at least 1.78:1 ratio for a widescreen digital projector; you could theoretically do 2.35:1 if you have enough width and length and can put up with additional image scaling and add-on anamorphic lenses).

    I would assume you have at least a 10' to 12' ceiling to work with so you could have two or three rows of seating (depending on the final length of the room). Then you have to determine sightlines and the angle of view. There are formulas set out by the Society of Motion Picture and Television Engineers (SMPTE group) to determine the best overall measurements (any good commercial theater worth its salt uses these guidelines in setting up a room). For the prime seats you want about a 15% viewing angle.

    Widescreen Review has some good articles by Joe Kane (the video God) from past magazines on how to set up a theater for optimum viewing pleasure. He's right, the room may be somewhat "ugly" to your significant other, but it must be PITCH BLACK in the room when the lights are off.

    F. Alton Everest's newest edition of his "The Master Handbook of Acoustics" is a great book to start boning up on proper acoustics for various types of listening rooms (including home theaters).

    RPG Inc. makes professional studio and home theater acoustic treatments and has created software for determining where to place them given a room's fixed dimensions and where the seats will be placed. Much more precise acoustic engineering than just placing absorptive Theater Shield on the bottom of the room and reflective surfaces on top. Widescreen Review created a very, very good home theater using RPG treatments.

    There is also a "golden rule" for room dimensions that will yield the smoothest and most predictable frequency responses too.

    The AVS Forum is a good place to look at too.

    Dan
     

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