Question Home Cinema Design Priciples

Discussion in 'Home Cinema Building DIY' started by Pulsar, Nov 18, 2018.


    1. Pulsar

      Pulsar
      Well-known Member

      Joined:
      Jan 19, 2003
      Messages:
      3,172
      Products Owned:
      0
      Products Wanted:
      0
      Trophy Points:
      106
      Location:
      West Midlands - Stourbridge
      Ratings:
      +343
      Hi,

      I am in the very early planning stages of a dedicated garden cinema room. At this stage everything is up for debate including room dimensions / ratios, layout, screen size etc. Can anyone here recommend any resources that I can use to help self-teach some of the basics of good cinema room design?

      Thanks

      Rob
       
    2. Peter Parker

      Peter Parker
      Distinguished Member

      Joined:
      Apr 6, 2001
      Messages:
      13,551
      Products Owned:
      1
      Products Wanted:
      0
      Trophy Points:
      166
      Location:
      UK.
      Ratings:
      +3,056
      I like the CIH + IMAX option.

      So you fit the biggest 16:9 screen you can fit for your preferred seating distance, and you mask the top and bottom so you have a 2.40:1 screen.

      You watch 16:9 within the 2.40 screen height, and then zoom (or use an Anamorphic lens) to make the image wider for scope ratio movies. You will need a projector with lens shift as well as a zoom ratio of greater than 1.33. DLPs are usually restricted in that regard so other brands like Sony JVC and Epson will be more suitable.

      If you get a movie that has aspect ratio changing for IMAX elements (The Dark Knight, Interstellar, Dunkirk etc), you keep the image zoomed to the width and just remove the top and bottom masking so the IMAX portions are visible when they occur. That way all movies are presented correctly with respect to their aspect ratios and the largest movies are seen largest, and the smallest as smallest.

      For this to work you have to ensure your seating distance is close enough so that 16:9 is as large as you feel comfortable with, so that it doesn't feel too small. That's usually based on how tall an image is as taller images become more uncomfortable to watch over long periods than wider ones.

      THX recommends a seating distance of 2.4 x the screen height for the primary seating position, with 3.68 x the SH for the back row. SMPTE/CEDIA recommend sitting no closer than 2xSH (and no further back than 4xSH, with a starting point of 3xSH), and no seats closer than would provide a vertical viewing angle of 35 degrees or more, with 15 degrees max being recommended. IMAX viewing is a little different with these rules but the usual rules for scope can apply there.

      What we usually recommend is projecting an image onto a wall and experiment with different image sizes and ratios, as well as different seating distances, but most people end up within the guidelines.

      Dolby, THX, SMPTE and CEDIA all have guidelines to which commercial theatres are built to and most of it can be found online if you want to build something that will be similar to commercial theatres/screening rooms.

      Square rooms are usually considered bad.

      Having an acoustically transparent screen with speakers behind is one approach, and having the room covered in black velvet so that you can only see the projected image is considered good for image quality. Reflections from the screen onto reflective surfaces and back onto the screen can reduce intra-image contrast and sometimes be a visual distraction. Some people like a room that is visually pleasing when the lights are up so you have to decide what you prefer.

      I suggest you use Dolby's commercial guidelines for speaker placement, especially with respect for Atmos:

      https://www.dolby.com/us/en/technologies/dolby-atmos/dolby-atmos-specifications.pdf

      Don't have seats against the back wall, and try and keep speakers at least 4ft away from ears. Surround speakers should be at approx ear height to give a larger separation to the ceiling Atmos speakers. That's not always possible in small rooms with multiple seats and rows.

      Acoustic treatments usually help too.

      That should get you started.
       
      • Agree Agree x 3
      • Thanks Thanks x 2
      • List
      Last edited: Nov 18, 2018
    3. DougAP

      DougAP
      Well-known Member

      Joined:
      Oct 14, 2012
      Messages:
      1,471
      Products Owned:
      0
      Products Wanted:
      0
      Trophy Points:
      116
      Ratings:
      +699
      • Like Like x 1
      • Thanks Thanks x 1
      • List
    4. DougAP

      DougAP
      Well-known Member

      Joined:
      Oct 14, 2012
      Messages:
      1,471
      Products Owned:
      0
      Products Wanted:
      0
      Trophy Points:
      116
      Ratings:
      +699
      Cross-posted with @Peter Parker , but glad to see we agree on the first principles to consider!
       

    Share This Page

    Loading...
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice