Riser filling

Discussion in 'Home Cinema Building DIY' started by chantrys, Jan 7, 2012.

  1. chantrys

    chantrys
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    I am about to have a riser built for a second row of seats in my cinema. The riser is being installed on top of the existing carpet & underlay and we will be using the same carpet & underlay to cover the riser, but can we leave the frame empty or should it be filled with something?

    Many thanks.
     
  2. Peter Parker

    Peter Parker
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    Fill it with rockwool insulation to prevent cavity resonance.

    If you look over on the home theatre builder section of avsforum, you'll see plenty of images of people building risers and how they did it.

    Gary
     
  3. poolside

    poolside
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    Hi chantrys. I came across this same question a few years ago when designing my own cinema room which has a seat riser and stage riser. My research at that time did highlight the need for some form of filling in order to stop a timber box section riser from 'drumming'. Two prime options were recommended; stuffing with a high density wall insulation or filling with dry play sand. The later could be a messy option - depending on circumstances. I finally went for for a solid concrete design given that I had the materials to hand (no additional cost) and it was a dedicated construction/room.
     
  4. chantrys

    chantrys
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    If I got a base fitted to the riser to make it a fully enclosed box, it may work out cheaper to use sand. I'll have to find out if the extra cost of the wood negates the savings of using sand.
     
  5. Peter Parker

    Peter Parker
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    You can fill a riser with sand or cement (commercial theatres are often built with concrete risers), but usually they fill just the (domestic) stage with sand to help with the effect a stage mounted sub woofer will have. They also usually mount the stage on a sub floor that is isolated from the main floor. A riser doesn't necessarily require the mass that a stage might.

    Using rockwool is a quick and easy method IMHO and is easy to remove if the room usage changes, but either method works. You're going to need a lot of sand to fill a riser and rockwool is pretty cheap these days (from around £5 a roll)

    Here's a link to an Erskine designed room showing both stage and riser construction:

    Another Erskine-designed masterpiece (if I don't screw it up). - Page 3 - AVS Forum

    Gary
     
  6. chantrys

    chantrys
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    thanks Gary.
     

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