Home Cinema Conversion by 1st December 2020 - What size PJ Screen? -


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Ok Guys,
I'm starting on my integrated garage conversion (this is under the main living room and exactly the same size) which is in a 20ft (6.1metres) x 17ft (5.18 metres) room and will be dedicated to all things cinema. The premise is, it's currently a solid concrete floor, will be building false wooden insulated floor. Two 8ft french doors on the right side to repalce the garage doors, complete rewire and the garage is twin skin so brick AND breezeblock so will be insulating everything. It'll be having 11.1 Atmos sound and I've already decided on the amp and speakers etc. However, this is my query! SCREEN SIZE!

I'm currently running the Sony VPL-VW320ES projector which is 4k and has a maximum 2.06x zoom from the specs. It will have Denon 6400H amp with Q Acoustics 3050 front, 3090 centre, 3050 side and rears and not decided on the ceiling speakers as want to run a 7.1.4 system.

Currently the PJ is using a 100" screen in the living room (which is above the integrated double garage that I'll be converting) but is also running across the living room i.e across the shorter 17ft. The cinema room will be switched the other way around allowing the the projector to use the 20ft length of the room meaning I can go bigger on the screen as 100" is too small. However.... that's by the by...

Current SCREEN 100"
  • 100" Screen Diagonol,
  • An 11.4ft/137" (3.47m) Throw Distance from screen,
  • Zoom at 1.92x (calculated)
  • Calculations give approx 125nits
  • Picture is fantastic.

So, the query I have here is, I fancied using a 150" screen but I don't think I'll have enough throw or space with this PJ, so now looking at a 140" screen instead. This would allow me a maximum throw and to place the PJ basically as far back as possible say at 4.6 metres, so basing the throw on 4.6 metres, this would give the following:

New SCREEN 140"
  • 140" Screen Diagonol,
  • A 15.1ft/181.5" (4.61m) Throw Distance from screen,
  • Zoom at 2.05x (calculated) which is the maximum zoom the PJ does...
  • Calculations give approx 83nits

So, obviously the extra 1.14 metres of throw and that increase in picture size really suck the estimated brightness out of the picture, what's peoples advice here with what I'm trying to achieve and given the screen size in the room I'm going for... do people think this is a mistake, I just don't want 100" again, I wanted bigger... suppose there is a possiblity of using a 120" and reducing the throw thus increasing the brightness but I wanted to go BIG as we all usually do.

For reference I'll be sitting around 15ft back from whatever size screen I use.

What's peoples thoughts on this, as this is costing me £10k to get the room converted. I don't want to get this wrong, but there's a wealth of experience on these forums and I'm open to all ideas!!!!

EDIT: Just for reference if I went 120", the following would be used...

New SCREEN 120" if I went just 120"...

  • 120" Screen Diagonol,
  • A 15.1ft/181.5" (3.94m) Throw Distance from screen,
  • Zoom at 2.05x (calculated) which is the maximum zoom the PJ does...
  • Calculations give approx 113nits
Last edited:


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