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Discussion Starter · #1 · (Edited)
The first six posts are where my updates, summaries, etc, get posted. Assume the rest is an ongoing process of discussion and thinking out loud.

  • Seating Plan -- because everything else emanates from how many people (and how they are arranged) in the room. The Forest Screening Room
  • Dimensions & General Acoustic Isolation -- because that is the next variable to nail down. Sometimes it is not adjustable and just a given fact. In this case, at least for now, I have some flexibility. The Forest Screening Room
  • Gear & Line Level Voltage and Low Voltage -- shouldn't be selected until the above factors are figured out, so this is just a placeholder of possible ideas for now. The Forest Screening Room
  • Design -- by which I mean the 'look' of the theater....The Forest Screening Room
  • Acoustic Treatment & HVAC -- not to be confused with noise isolation which will take place in the Dimensions step targeting NC20....The Forest Screening Room
  • Detailed Acoustic Isolation Build Details & Ballpark Budget -- as a wild ass guess based on what things have cost before, this will answer the question "what does that gear cost" even though that's not the most expensive part of the build (not even close) and I'm not buying all new gear. The Forest Screening Room



———————-
Background: we had to leave my theater of 15 years this spring, when we downsized into that next phase of life.

The last theater was built into a detached garage and it worked very well. The new house is too small to build a theater in the house. But, we will build a detached garage or similar outbuilding, so I plan to section off part of that for the same purpose.

We won't be able to break ground on the garage until next year, so this is a planning thread for now. But it turns out the general plan for the room is important to the extent it impacts what we build. And around here it can take six months from drawings to permits so the clock is ticking.
 

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Discussion Starter · #2 · (Edited)
Seating
  1. Single row of theater type seats
  2. Really only require two seats but will go for three because I want one seat that is smack in the center
  3. Single row of bar style seating behind the theater seats for overflow / eating more complicated foods
  4. Our last theater could seat seven people at its max configuration. The usage was probably:
    • 75% 1 person,
    • 20% 2 people,
    • 4% 3 people,
    • <1% more than 3 people.
  5. Since the seats in our temporary theater are downright unpleasant, this is the one piece of gear I may buy in advance since I can use them right away and need them right away! Caveat is that I can only fit two seats in the temp room, and we need three for the theater……and we almost have nowhere to store a third for the 1 to 2 years between now and then. So I’d need to go with a brand that has some consistency with models over time or make room in our modest attic to store a third. Used, if high quality, is fine, too. I’ve got an ad in the classifieds section and automated searches of Craigslist and eBay.
  6. Seating specifications:
    1. Need at least 50 inches from butt to footrest. Shorter, and the footrest will end up on my ankle and not my feet. Strangely, lots of chairs especially many discount models don't meet this requirement.
    2. Need to have the option to have the footrest fully extended before the back reclines at all.
    3. Motorized headrest. Must be tall enough to really support the head. But not much more/taller. And ideally not super wide. (Support versus blocking sound is a balancing act.)
    4. Removable arm rests -- I think. There are tradeoffs and this might go either way.
  7. update: got two Valencia Zurich seats to test drive in the temp room. Not bad but nothing special either, ie, very similar to others at this price point.
 

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Discussion Starter · #3 · (Edited)
Dimensions & Sound Isolation (the shell)

Dimensions

  • There are of course practical considerations even though this is a new space being built:
    • Too large, and I end up not being able to use a consumer level projector like a JVC NX5, so to get the necessary light output on the same budget, I end up with an inferior projector. So that limits how large the screen can be, and what the minimum throw distance is, what the seating distance is etc (which is all fine).
    • Too large, and I spend more money filling a space with high quality sound and have to compromise on the sound quality in order to have the requisite SPL.
    • So I'd rather size things for our usual usage and allow the occasional larger gathering be compromised.
    • In general, the more space devoted to the theater, the less space for other uses in the garage.
    • In general, the more money spent building out a larger space, the less money for other things.
    • I think it will be tough to go over 12 feet in height.
  • So far, the best combination (as small as is reasonable, but with enough space to optimize performance) appears to be the following because it allows for the two most likely screen and seating positions.

    12.5' tall*
    15' wide**
    18' deep (update: after much discussion is seems like 24' is safer. i don't have to add a second row but this gives me the option later to do a full on riser and recliner second row)

    because in this case:
    a) the screen could be two feet into the room on a false wall and I could sit 10 feet from it, putting me at a 1/3 spot for room modes purposes, and have the right "field of view" for my eyes.
    b) At the same time, the screen could be baffle mounted on the wall of the room, if desired, which again if I sit 10 feet from it, places me at the 55% spot in the room length which is ALMOST as good (in terms of room modes) as 1/3 of the room.
    1. *Actually, a height of 9 feet works better for room modes in the sense that it places the ears when seated at about 1/3 of the room height, which is better than where they would be with a 12.5' ceiling even though 12.5' would look better and create the fewest room modes. 15‘ tall would also work placing ears at 20% of room height. Ideal dimensions for a two row theater: The point of...
    2. **This width might be a little tight for a three seat row PLUS 4' on each side to allow proper distance from the surrounds.
  • But 21( or 24) x16x9 (or 12) may make more sense
    1. This would allow up to 2.5 feet behind fabric on each side, so subs are easy to hide in each corner.
    2. Acoustic treatments could be as large as is ideal
    3. I could even get creative with the shape of the room, doing a taper or stepped design where the room appears to get smaller towards the screen
    4. A gear rack could be behind the fabric
  • UPDATE:
    • Turns out due to budget and site constraints, the building can only accommodate at 10 ceiling. So the finalized plan has a theater of 19x14x10.
    • This will make a second fully reclining row possible but not ideal. Luckily I am 99% interested in the main row, and don't plan on recliners for a second row.
    • Acoustically this looks nice too for modal characteristics:
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Isolation
  • Construction techniques/requirements:
    • HVAC and general sound isolation close to NC20
    • Fresh air intake/exchange via a ducted minisplit
    • Double wall and ceiling, room within room construction
    • Using a small lobby as the airlock between two acoustically optimized solid core and well sealed doors
    • Lobby as part of the room within room construction
    • Minimal wall penetrations (ie, no outlets and lights nor speakers etc penetrating the shell -- all surface mounted in the room behind fabric panels)
    • More details and discussion in this thread: Critique my private cinema specifications for my builder
      1. Detailed Framing Notes for the Builder:
      2. Alright, all this input is much appreciated and I look forward to getting schooled on an ongoing basis! Let me have it.

        Politely.

        ---

        Here is where I am at in my thinking for the framing notes.

        Again, I would LOVE to be corrected / questioned / advised further. I don't consider this definitive but just as good as I have been able to make it so far.

        For example, this "sketch" is just to make sure the shell is sufficient in size for what I know I want now, and with a little room to grow (second row) if desired later.

        View attachment 3238816

        View attachment 3238818

        View attachment 3238820

        View attachment 3238822

        View attachment 3238823

        And liberal use of the SoundProofingCompany diagrams since we'll be buying the key materials there (eg, GG) and their diagrams are the best way I can see to help communicate to the contractors what the right use of them is:

        View attachment 3238826

        As you can see above and below I have had to modify them a little for my plan since I want one of the usual drywall laters to be OSB or plywood to make it even easier to install stuff anywhere (which is what I'll end up doing since everything is surface mounted), as well as fighting against raking etc.

        View attachment 3238827

        View attachment 3238828

        And then the usual caveat about what GG is and how to use it, because to civilians it is a huge mystery.

        View attachment 3238830

        And this kind of nice detailed instruction. They may not read it and remember it but at least I'll be able to remember it with this, share the photo, etc., in the moment.

        View attachment 3238831

        (Thanks to write ups Jeff P has done for the following tips.)

        View attachment 3238838

        View attachment 3238845

        View attachment 3238846

        View attachment 3238850
  • Specs from "Home Theater Recommended Practice Audio Design Home Theater Recommended Practices/ Audio Design CTA/CEDIA-CEB22 R-2018 (Formerly CEA/CEDIA-CEB22)" available for free from Consumer Technology Association Publications Store or you can pay upwards of $75 to download it from other sites.
    Font Screenshot Document Number Parallel
  • We will be trying to achieve Level 2 minimum and build with Level 3 in mind/goal. So, what does that mean?
  • Font Parallel Rectangle Number Pattern
  • And in our case, we care more about the first principal since this is a detached building.
  • Rectangle Font Circle Number Paper product

  • Font Rectangle Circle Number Art
How to assess? Again, we will target the Premium level but not worry as long as we exceed the step down level.
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Ultimately this focus on a single noise floor number obfuscates what may matter and what may not. This thread is a great discussion, and shows where deviations from the goal may be okay.


But in summary:

View attachment 3318919

Which looks like the following

(freq, audibility threshold)

20,63.54
30,49
40,40.33
50,34.26
60,30.32
70,27.35
80,24.6
90,22.52
100,20.8
143,15.72
200,12.25
300,9.8
400,8.3
500,7.5
600,7.3
700,7.2
800,7.2
900,7.2
1000,7.2
2000,-0.3
3000,-5.2
4000,-4.86
5000,-0.74
6000,7.65
7000,14.3
8000,18.88
9000,21.3
10000,20.44


HVAC & Noise Floor (since HVAC is often the weak point)

  • Theater:
    • Noise Rating (or Noise Criteria) should not be more than 22 measured .5 meter from any diffuser in Theater. (Discuss if this becomes problematic.)
    • General goals: The theater system should maintain 72 degrees (and below 55% humidity) with an outside temperature range from 30 degrees to 99 degrees F for up to 7 people in the room for several hours.
      • But usually we will only have 2 to 4 people in the room, so if that helps adjust the plan, let’s discuss.
    • Air exchange: 8 air exchanges through the handler per hour seems to be the normal goal.
    • Fresh air: target 12-15 cubic feet of fresh air per hour per person.
      • So, 7 people at 12-15 cubic feet of fresh air per person per hour would mean we should target 84 to 105 cubic feet of fresh air per hour but since we will seldom have more than four people in there, 60 cubic feet of fresh air per hour is likely adequate and maybe easier to accomplish?
  • Lobby/Gear Room:
    • Noise Rating / NC35 is okay in the lobby. So potentially a wall blower could work (ductless system)?
    • Capacity: It could generate as much as 6000 btu per hour from equipment but usually under 4000 btu per hour. Allowed to have more temperature swings than the theater.
 

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Discussion Starter · #4 · (Edited)
Gear

Although it should go without saying, I will say it anyway. This is just a placeholder list. The most important piece of gear is the room, and everything will flow from how that shakes out in terms of dimensions, and acoustic properties.

That being said, this is AVS and everyone asks about gear, so this is a sketch of one possible set of gear.

Screen
  1. A cinemascope screen.
    1. I like close to a 55-60 degree field of view for widescreen 235:1 films. Additional testing shows 55 minimum is my requirement.
    2. That means 178:1 movies are about 45 degrees, which is great
    3. Another way to think of it: I like to be about 2.4 screen heights back from the screen.
  2. Acoustically transparent
    1. Given the wide angle of view I'll likely have all three speakers behind the screen.
    2. I will have enough space behind the screen to allow for micro perf as an option but hope to avoid that.
  3. Size: Given my front row proposed seating distance of c.10 feet, a 10 foot wide screen may be ideal.
    1. I may get a 16x9 screen and more or less permanently mask it to 2.35.
    2. I may get a standard size frame that can be adapted to whatever material ends up being best.
    3. That means 135" diag is too small (under ten feet wide) and the next standard size up is often 150" diag, which is technically almost 11' wide. If I go that way, I may need a slightly positive gain screen with the class of projectors I am considering and or use a minimum throw distance.
Speakers
  1. 9.4.6 is probably where I end up.
    1. Since I'm optimizing for a single row, two subs might be enough to start with.
    2. I don't see a reason in a room this size for six overhead speakers but I'll wire for that, just in case and suspect Ill just run four at first.
  2. No interest in compromising placement to make the second / bar row sound better any time it detracts from the real seats.
  3. Pretty agnostic regarding brands. Will seek best in the price range my budget allows at the time. I lean toward high output capable brands that have a reputation in this space like the Triad, or JBL kind of approach. (I like Revel in a domestic room but they don't seem optimized for a theater space. I'll continue to use them in my living room. Heck They are not even adding their data to the CEDIA design tool!)
    1. If going with Triad, this is what they recommend for me (Bronze could cover a single row theater, including four Bronze subs, but Silver would be better and allow the quasi back row a better experience, though Silver subs would not be necessary.)
    2. Details:
      Suggested room sizes/seating distance for achieving 105dB in a SEALED room
      Room SizeMax Seating distance from LCR
      Cubic MetersCubic FeetMetersFeet
      Bronze System
      3 Bronze LCR, 2-4 Bronze Surrounds413
      With 1 Bronze Sub501,765
      With 2 Bronze Subs802,825
      With 4 Bronze Subs1304,590
      Silver System
      3 Silver LCR, 2-4 Silver Surrounds516
      With 1 Silver Sub1003,531
      With 2 Silver Subs1505,297
      With 4 Silver Subs2308,122
      Gold System
      3 LCR/Center, 2-4 Gold Surrounds619
      With 1 Gold Sub1404,945
      With 2 Gold Subs2107,416
      With 4 Gold Subs30010,594
      Platinum System
      3 LCR/Center, 2-4 Gold Surrounds826
      With 1 Platinum Sub1505,297
      With 2 Platinum Subs2207,769
      With 4 Platinum Subs33011,654
  4. All speakers will be hidden. Would like to hide the subs (like two behind the screen). But in the rear that gets slightly less easy though should still be doable.
  5. While I am tempted by a baffle wall, I worry that it limits future options and limits my ability to have extra room length behind the screen that is sized to optimize room mode behavior, and or provide space for more trapping, etc.
Audio

Processing: Hard to predict what processing options will exist 12 months from now, but we are seeing stuff that can handle this number of channels drop into the $3k range. I'm partial to Anthem but not beholden. (On a temporary basis could press the old MRX720 plus external amps where needed into use while shopping for the next great thing.)
Power: Amps are amps if they are operating correctly and used within their design limits. Something like a set of Behringer A800 could do the job well, for example, depending on speaker, room, etc. I don't use an amp as a tone control.


Projector

I'll be eagerly watching how the JVC NZ series of projectors perform in the real world since that is the way I'm leaning for projection. (Have an RS500 on hand from the last theater, that I am using in my temp setup, and could press into service in the new space at any time while sourcing something better.)

The key will be actual peak light output for the expected life of the illumination source (which is interrelated with the screen choice and size as well, or course, so the two may inform one another).

  • 22 ftl minimum using rec 2020 for hdr (appreciate more) for it's full life
    • in my use case, 1000 hours a year for ten years
    • im okay with replacing the lamp every 1k to 2k hours
  • 2. and then solid sdr using the following kinds of criteria dovercat summarized when researching 3d specs:
@dovercat collected the following info in another thread:



For 2D digital cinema

Digital Cinema Initiatives, LLC, Digital Cinema System Specification Version 1.2 March 07, 2008

Nominal Projected Image

ambient light level projector off 0.01cd/m2 (0.0029ftL)

white luminance 48cd/m2 (14ftL)

luminance uniformity 85% of center

minimum sequential contrast 2000:1

minimum intra-frame contrast 150:1

transfer function down to 5% peak white. 2.6

color accuracy match

Review Room

ambient light level projector off 0.01cd/m2 (0.0029ftL)

white luminance 45.6-50.4cd/m2 (13.3-14.7ftL)

luminance uniformity 80-90% of center

minimum sequential contrast 1500:1

minimum intra-frame contrast 100:1

transfer function down to 5% peak white 2.6 +/-2%

color accuracy +/-4 delta E

Theatrical Presentation

ambient light level projector off 0.03cd/m2 (0.01ftL)

white luminance 37.8-58.2cd/m2 (11-17ftL)

luminance uniformity 70-90% of center )

minimum sequential contrast 1200:1

minimum intra-frame contrast 100:1

transfer function down to 5% peak white 2.6 +/-5%

color accuracy +/-4 delta E


Ideal viewing distance 1.5-2x screen height, maximum viewing distance 3.5x screen height


I am uncertain if the white luminance above is for peak white or reference white, as term peak white seems to be used occasionally when referring to reference white. I have read conflicting information that DCI has a peak white of 15.28ftL and a reference white of 14ftL. Could someone clarify this for me?

According to the UK Film Council Digital Screening Network content projected in Rec.709 colour space is assumed to have been mastered for a display gamma of 2.45. So projecting blu-rays should be at gamma 2.45.



For film print cinema

What I have read elsewhere on the web so may not be reliable.

I have read traditional 35mm color film print 400:1, sequential 1600:1 pre 1997, 4000:1 from 1997. With film print in theory capable of 10,000:1 but in practice limited by the dynamic range of the negative and further reduced by projection flare. Resulting in a projected sequential contrast ratio of about 3000:1 and intra-scene contrast of about 500:1. SMPTE 196M minimum on screen contrast ratio 400:1. Typical theaters around 2000:1 - 1,000:1 with intra-scene contrast as low as 150:1 - 100:1. Do these figures sound about right?


Gamma is s-curved with the center being about gamma 3.0


Assuming a film transmissivity of 87%, the SMPTE 196M specified 55cd/m2 (+/-7cd/m2) 16ftL (14-18ftL) for professional screening rooms equates to approximately 14 ftL from a film projector running with clear (D-min) film. SMPTE 196M states that commercial cinemas must provide 12 ftL to 22 ftL at the center of the screen measured from viewers location, with luminance uniformity 75-90% and the edges of the screen measuring at least 10ftL. Room reflected light should not exceed 0.25%. ITU standard is 10ftL to 14ftL with luminance uniformity of at least 75%.


Kodak document on scope and flat apertures states "Typically, a projector set up to produce the SMPTE standard 16 footlamberts screen luminance for the 2.39:1 aspect ratio "scope" format will have only about 13.4 footlamberts for the 1.85:1 "flat" format, even though the "scope" screen image is wider"

"The introduction of CinemaScope by 20th Century Fox in 1953 remains one of the most significant engineering achievements in motion picture technology. The technical triumph of the "scope" format is its elegant simplicity. The anamorphic lens allows the use of the maximum image area on the film, and puts it on the screen. A larger image area gives pictures that are brighter, sharper, steadier, and less grainy. In contrast, the current 1.85:1 "flat" format evolved simply by cropping the available film image area and projecting it at greater magnification to produce a widescreen picture, at the expense of both light and image, and a waste of available film area on the print."


Lucasfilm Theatre Alignment Program (TAP) showed the average screen luminance in first-run theatres to be about 11ftL center. Just under half of all complaints to a phone THX hotline were that the image was slightly too dark, with the next most common complaint being the image was extremely dark. Buena Vista survey of thousands of screens reported in 1997 to have found an average of 8-9ftL center. Kodak operation big screen survey of first run theaters in the same year found an average of 6-8ftL center. According to Kodak even at 12-13ftL the image in medium and dark scenes lacks detail due to insufficient brightness.


I am somewhat uncertain about white being 14ftL as I have read elsewhere that the 16ftL open-gate figure translates to 12ftL with film running.


SMPTE 196M color temperature 5400K +/-200K


SMPTE recommends the screen occupies at least 30 degrees of the viewers field of view.


Viewing distance, 1953 research by 20th Century Fox when developing cinemascope 2.35:1 determined screen should occupy 45 degrees of viewers field of view. Due to film granularity, jump and weave becoming problematic closer.


THX

Center of screen 16ftL +/-2ftL, 5% in from the edge no less than 75% and not more than 85% of that at the center. No part of the screen should be less than 10ftL

Center resolution 68 lines/mm or more, side resolution 56 lines/mm or more, corner resolution 40 lines/mm or more.

Maximum viewing distance, screen occupies at least 26 degree, recommended 36 degrees from most distant seat

The SDR requirements are easier to meet that HDR and wide color, so the latter will be the limiting factor. Laser might be an option, but since I don't put general use hours on the machine, the extra cost is hard to justify (especially since the color coverage versus light output is lower) and a ten year old laser projector, even with a decade of life left in it is likely not a hot commodity on the used market). Plus it means building in a lot of headroom.

But hopefully we have lots more real world info over the next several months.

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LINE LEVEL & LOW VOLTAGE

  • Projector outlet (rear center of ceiling) surface mounted two gang box, connected to power inlet in equipment stack location (another two gang surface mounted box)
  • All other outlets also mounted inside theater shell as surface mounted boxes. (If holes are cut for electrical boxes they must be dressed with putty pads.) Leave extra service loops at each location with wires hanging inside of room passing through small caulked holes.
  • All outlets on same phase leg of subpanel.
  • Two in-floor outlets. These will need to have conduit inside the slab. One at 55% of room towards rear, and one at 66% of room towards rear.
  • Zone lighting circuits in room, recessed lights over screen, sconces, ceiling recessed fixtures front of room separate from rear of room, step lights for safety All lights on dimmers. Consider connected controller with simple key pad in room. Any holes cut other than soffit and riser lights need to be in backer boxes or covered with putty pads. Or, better, all such items will be surface mounted in the screening room so just run wire through a caulked hole for connection to a surface mounted item later.
  • Six dedicated 20 amp circuits for outlets (use 10g wiring)
    1. 3 at equipment stack location in Lobby.
    2. 3 for screening room – one for the two floor outlets and two for the walls
  • 4 independent lighting circuits in the screening room plus one in lobby
  • Install whole house surge protection in the subpanel for the garage.
  • Bathroom should be on its own circuit including the lights and the exhaust fan.

Acoustically isolate the power (line voltage) and low voltage intrusions, and keep them separate from on another:

  • Where wires coming into the theater, seal the hole with acoustic caulk.
  • Do not install an in wall receptacle, but instead run a single wire and then install/mount the electrical box as a surface mount (both for electrical outlets and for lighting circuits). Surface mount everything.
  • Conduit through wall should not touch exterior structure, and the penetration on the interior structure should be a little larger than the conduit and sealed with acoustic caulk.
Property Product Wood Interior design Floor



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Low Voltage

CONDUITS:
  • Between lobby and Theater, at least four 2” conduits for low voltage wiring, connecting lobby (gear rack area) – one to each wall in the theater— 45 degree turns max
  • AND one 2” conduit to projector location (center of ceiling one foot from back wall, by entry door of theater)
  • All these conduits will be EMPTY for now other than draw strings.
  • Conduit edges should not touch exterior structure and wall penetrations should be slightly oversized so that caulking rather than conduit touches the drywall
Treat lobby this as a home run for structured wiring for the theater and entire “garage” building
Wiring for thermostat at back of theater
In outer /overall building, with termination/home run in lobby, in conduit from the main house:
  • Three runs of CAT6E cable
  • Two runs of coax cable
  • Pull strings

INWALL RATED LOW VOLTAGE
  • I will provide and rough in
  • Speaker wire runs
    • Three speaker wire runs to front wall (West)
    • Three speaker wire runs to each side wall
    • Two speaker wire runs to read wall
    • One speaker wire run to each corner (=4)
  • Coax Audio runs:
    • One to each corner (=4)
  • Balanced audio runs:
    • One to each corner (=4)
  • Ethernet:
    • Three CAT6E to front of screening room (home run to lobby)
    • Three CAT6E to in-room projector area
    • One CAT6e to each side wall
  • No wall penetrations for wall plates just caulked holes (unless otherwise discussed and agreed)
 

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Discussion Starter · #5 · (Edited)
Design

Reserved for plans, sketches, renders. For now, this some key looks and ideas, and then a color scheme, fabric choices, seating choice. This is lower priority since defining the shell size, construction technique, and isolation requirements is the most timely piece so construction on the garage (in which these rooms will be the "bonus room") is the key milestone to achieve so things can move forward. But some of the principles like fabric walls and a combination of fabric and a large slatted bass trap type ceiling are important aspects since they define some of what ends up being important in building the shell.

It's a movie watching machine.

We are fans of minimal design. And form following function is typically our thing.

For example, a two tone look with a purpose:

Building Event Font Room Rectangle



Or this cool looking ceiling which is actually a giant bass trap where the slats are used for diffusion (really just to prevent too much high frequency absorption) with a very thick and spaced bass trap above:

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And out of 100s of images of theaters online, THIS is my wife's favorite. (I'm okay with it because my last theater was a black box and that was fine for me.).... Though of course the floor and ceiling need to be as dark as the walls......and I don't mind the idea of hiding all the speakers and acoustic treatment behind fabric...in fact its what I prefer. I have had "industrial" looking spaces where speakers and treatments were the flavor. I'm older and more chill now, and the sleek clean look appeals to me.




---

Fabric walls: Acoustimac Executive (Fabric wall covering choices (DMD versus GOM versus GIK)) where the results were revealing since there will be speakers behind the cloth so some chooses are sub optimal.

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So swatches were acquired. Two schemes look workable.

Brown Rectangle Textile Grey Font


Brown Textile Road surface Rectangle Wood


But these are shown with a brown leather swatch from Octane, since I inferred the wife would choose heated massage enabled theater seats over anything else…….but she much preferred a cleaner look, so it now appears to be the Valencia Zurich that wins.

Furniture Rectangle Comfort Armrest Chair


That’s not bad. I too prefer the cleaner lines, and for me the power headrest and lumbar were the key, so….win win, right?

Well, almost, except that the Zurich is only stocked in black. Other colors can be custom ordered but lead times can be as long as six months….and getting more seats later on that match becomes more complicated…..and we only have room to use two until the theater is built.

So that helps shift plans to the “Executive” style fabric, I think, for the walls.

Rectangle Font Line Material property Parallel


Though I will keep in mind for limited use (not fire rated) that this stretch velvet is pretty acoustically transparent too:

Rectangle Slope Font Line Parallel
 

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Discussion Starter · #6 · (Edited)
Acoustic Treatment/Plan

My last room was based on a plan from GIK, combined with ideas gleaned from white papers from places like Harman research, and it was optimized/calibrated by Accucal on site.

This time I’ll have more flexibility and would plan to get more consultation ahead of time. And I will eventually cover the walls with fabric for a clean look.

In terms of measurable outcomes/goals, getting the reverberation time / decay time down to c .25 seconds, and smooth even response through multiple subs and other trapping are key.

In general, I'll be following the specs from "Home Theater Recommended Practice Audio Design Home Theater Recommended Practices/ Audio Design CTA/CEDIA-CEB22 R-2018 (Formerly CEA/CEDIA-CEB22)" available for free from Consumer Technology Association Publications Store or you can pay upwards of $75 to download it from other sites.

In particular, these pieces:
Font Document Number


And this more specific set of criteria that Dolby uses in their mastering room specification:

Font Rectangle Number Parallel Slope
 

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Discussion Starter · #7 · (Edited)
Acoustic Isolation Builder Details


This video does a nice job of summarizing what it takes, though he doesn't emphasize enough that one needs to do all these things together, not just some of them, to get the best results.



Here is how I'm describing it in writing.

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and then a few pictures adapted from the SoundProofingCompany

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then some detail on GG and drywall hanging

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And then the ceiling:


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And the doors

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with an exemplary picture/job from a fellow AVS-er

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The floor

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The HVAC

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including CEDIA guidelines



and details about wall penetrations, low and line level voltage

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Budget/Shopping List

(this is an ongoing list, just a place to keep track of likely pricing but I'll wait till construction is at the point that it requires purchases)


Shell of room including HVAC -- NA (part of garage cost)
Interior false wall framing -- 10k
Treatments -- 5-10k (depends on amount of DIY etc but since it is all hidden behind acoustic fabric, it doesn't have to be pretty, just good, eg, decay time around .25 seconds, linear response, etc)
Projector -- 12k
Speakers -- 10k
Subs -- 7k
Controller and Amplification -- 5k
Screen -- 2-4k
Seating -- 10k
Fabric and system -- 4k
Misc -- 5k
Carpet — 2k
Consulting -- 1k

but the truth of the matter is that I have most of the speakers, subs, AVR, some amplification, some of the seating, and a projector in storage or a temp room, so these numbers are just for illustration because sometimes people ask about budget and this gives a good ballpark summary.
 

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Discussion Starter · #8 · (Edited)
Update:

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General building situation finalized. Green represents the room within room, 19x14x10 interior dimensions.


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(EDIT: This post is where the thinking about loud, floating bad or incomplete ideas to get feedback and think through how to make things better begins. COMMENTS welcome!)

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We learned from the last build that we used one row of seats 95% of the time. So this time I'll not bother with a riser or a second row of seats, and just put a bar-style table and chairs behind the main row for those rare overflow occasions.

The goal would be to not bother with a riser, and to have the "bar" low enough that is doesn't interfere with audio....so it might be table height or counter height and not bar height.

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So what does a room meeting these requirements look like?

This room layout achieves the right immersion / angle of view.

Those aren't dual walls. That is just my limited skill set with this software.

The interior wall is a fabric wall on three sides, allowing cable runs and acoustic treatment and hiding of the side and surround speakers.

The front wall is a false wall with an acoustically transparent screen.

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Discussion Starter · #9 ·
Better audio:

These side walls don't allow the ideal four feet of space to the left and right of the listener for surround sound.

Here is what such a room setup would look like. In terms of audio, this is probably superior BUT it makes the screen FEEL less immersive (though when the lights are out and the walls disappear, the actual angle of immersion is exactly the same).

Conclusion: I think I have to "get over" what the screen looks like in the context of the room when the lights are on, and focus on:

1. Good audio
2. Appropriate immersion based on angle of view

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You should have an entire section on acoustical treatments. What are your plans?
 

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Discussion Starter · #11 ·
You should have an entire section on acoustical treatments. What are your plans?
Good call out.

My last room was based on a plan from GIK, combined with ideas gleaned from white papers from places like Harman research, and plans by people like Grimani and Mellor. It was optimized by Accucal on site.

All the gear was outside the room.

This time, I’ll be using fabric walls to enable more flexibility, and have additional space for even more options with subwoofer placement. Right now as the diagram hopefully indicates, I’ll have a full 12 inches of space between the real walls and the fabric walls with which to “play.”

Depending on budget I’d like to get additional consultation before the build commences rather than just bringing in a calibrator after the room is built.
 

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Discussion Starter · #12 · (Edited)
Maybe one solution to the desire to have the screen appear to go from wall to wall, but also needing a wider room for surround sound to be ideal, is this sort of stepped design where the room gets wider towards the rear?

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And to keep the shape manageable the stepped design could be largely an illusion:

you could make the trapezoidal walls acoustically transparent (Fabric) for the looks of the room and acoustically it will model like a rectangle. Mount your acoustic treatments on the solid walls behind the trapezoid.
 

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Discussion Starter · #13 ·
Here is something similar to what I’m thinking. I‘d do a wider screen or sit closer, moving the l&r just inside the screen edge, going 240:1. I’d probably move the wide surrounds to 90 degrees on the theory I don’t care about the bar row very much.

This quote is out of context and in response to another thread but I didn’t want to steal the image with crediting the author.


I see a lot of mentions about speakers, but no plan to go along with those choices. Choosing speakers should not be a brand thing, a cost thing, or how quickly can I blow my eardrums thing. It’s about getting the angles right, what can fit them in those locations, and deliver THX established reference levels to your seating location. Not to mention off axis response wall reflections, non screen interference, so on and so on. My humble suggestion, would be to take a look at the Dolby speaker angle requirements, get some graph paper, a pencil, and protractor, and draw your room. Use the 1/3 or 1/5 rule as a general rule of thumb to place your front row, draw the recommended angles from the seating location. Then, based on where those angles land, see if the speaker you are looking at purchasing will fit in that location. Things will most definitely go a lot smoother. I attached an image to help visualize it a bit better.
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Conclusion: I think I have to "get over" what the screen looks like in the context of the room when the lights are on, and focus on:

1. Good audio
2. Appropriate immersion based on angle of view

View attachment 3159701
I agree completely with your approach, the priority should always be performance, but looking at your diagrams you placed the MLP in the middle of the room. You didn't mention how many subwoofers you're planning to have, and their placement, but the middle of the room is problematic, bass wise.

Did you consider moving the seats forward or back a bit, to avoid potential problems?
 

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Discussion Starter · #15 ·
I agree completely with your approach, the priority should always be performance, but looking at your diagrams you placed the MLP in the middle of the room. You didn't mention how many subwoofers you're planning to have, and their placement, but the middle of the room is problematic, bass wise.

Did you consider moving the seats forward or back a bit, to avoid potential problems?
Great catch!

Given that I can add or subtract a few feet in any direction at this point in the process, my first reaction would be to add a couple feet behind the screen, effectively moving the center of the room, while maintaining my relationship with the screen.
 

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Discussion Starter · #17 ·
That would be better, yes. Try to put the MLP at the 55% length of the room. Performance wise, it'd be better if you could put the MLP at the 68% line, and it'd also look better, without all that empty space behind the bar, but 55% is your best bet, to get the 60° viewing angle.
68% line becomes challenging. Either that leaves a huge gap behind the seats (which might be okay if I had a smart idea for the space) or it places the seats too far from the screen.

But 55% is workable if I do something like:

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68% line becomes challenging. Either that leaves a huge gap behind the seats (which might be okay if I had a smart idea for the space) or it places the seats too far from the screen.
Did you consider placing the projector outside the theater? Is that possible? If it is, that would help solving the throw distance problem. You could move the chairs away from the middle of the room, and avoid having so much empty space behind the bar. And also save some money, because the room would be a bit smaller, and simultaneously eliminating the noise and heat from the projector.
 

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Discussion Starter · #19 ·
Did you consider placing the projector outside the theater? Is that possible? If it is, that would help solving the throw distance problem. You could move the chairs away from the middle of the room, and avoid having so much empty space behind the bar. And also save some money, because the room would be a bit smaller, and simultaneously eliminating the noise and heat from the projector.
That's not a bad idea and since I am working with a completely flexible space (this is going to be a room in a garage/shop) within reason, I can certainly do something like that. It would also be logical to have the gear in that same "projection room". I'll need to sketch some more models and see what that looks like.

Thanks for the idea.
 

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Discussion Starter · #20 ·
Maybe something like this, though I may not need so much room behind the screen now. That excess was just to manage bass modes. Basically I need enough space that subs can easily go back there AND ideally I'd have at least 12" space between any speakers I might choose and the screen itself, JUST IN CASE I use a perf screen at some point instead of a woven screen.


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