Home Theater Forum and Systems banner

New Home Construction - How big should the A/V room be?

8K views 35 replies 10 participants last post by  Fred33 
#1 ·
I'm planning on adding a theater room to a new house I am building. The room as currently designed is currently 8' x 11' x 23' on concrete slab but I have some flexibility in that size. I've done enough reading now to think that I should follow a plan something like this for designing my new room.

1. Pick a room dimension that provides better modal qualities. I've seen some standard ratios posted and 1 x 1.4 x 1.9 is one I've seen that would give me a room 8' x 11.2' x 15.2' or maybe 1 x 1.6 x 2.33 which would give me 8' x 12.8' x 18.67'. Given the other house dimensions it's harder to make the room wider than it is longer. It probably wouldn't be hard to raise the ceiling a little. Are there other dimensions that might work well in this situation?

2. Assume the first row of seats are 38% of the distance from the front and the second row of seats 76% of the distance from the front wall.

3. Pick a screen size and resolution that is appropriate from that distance.

Any thoughts on that general approach?
 
#2 ·
Given how much you'd have to shorten the room to get one of the 'perfect' dimensions (that aren't terribly perfect anyway - all rooms still have modal issues), I'd take the extra space any day. It opens up a ton of other options and much more flexibility in seating.

Try 38% and 62% for seating locations - or 62% and wherever the back row falls (as long as you keep it away from the back row).

Seriously, don't get too hung up on perfect dimensions -there aren't any. All you can do is avoid particularly bad ones. What you've described isn't bad though making the ceiling a bit higher would certainly help.

Bryan
 
#3 ·
I'm planning on adding a theater room to a new house I am building. The room as currently designed is currently 8' x 11' x 23' on concrete slab but I have some flexibility in that size....?
MY HT is 8 x 9 x 18 :yes::yes::yes: and is okay to me (it was a bonus room in the house).

You have to consider what furniture, equipment, lay out, etc... you wil be using here. I'm sure you want to have a nice set up. Like one of the post said: "Every room will have to be treated to have a great response" ... you will always have to use accoustical treatment. If you can, make the room bigger do it; if in the future you want to get extra furniture or change what you have, you won't be limited by the size of the room .....:T:T:T
 
#4 ·
Re: New Home Construction - More Questions

Thanks guys. This has been very helpful. Unfortunately every answer leads to more questions. Some Now I'm looking for some thoughts on how to allocate my budget. Since I realize my personal preferences have a big impact on any advice I'll give you some background.

I'm 48 and my wife is 50. We're building this house to die in but who knows. I've got a BSEE degree and a Masters in Telecom Management but I've gravitated more to the business side of Engineering and am more comfortable discussing foreign currency than Fourier transforms. When I buy things I want them to be high quality but not gold plated.

I am absolutely not an audiophile. My audio card and speakers are always the cheapest part of my computers. I'm more likely to listen to NPR than the radio and even less likely to listen to a CD. For this theater I want to hear the sound from all the directions the movie company intended but I'm unlikely to notice if the pitch is off. I'm considered borderline hard of hearing so I do think some sort of equalizer would be valuable so I can adjust certain frequencies. Since my wife has no hearing problems I'm wondering if there is something where I can preset one arrangement for me and one for her (and probably one for when she comes in a tells me it's too loud). :hush:

I am more interested in the video quality. I want to watch movies, TV, football games and play computer games (strategy not first person shooters). I'm thinking of buying a 1080p system so it will support the latest video/computer graphics 3 to 5 years from now but I don't want to waste my money either. When I buy a new computer I generally make sure I have the latest CPU architecture but I usually buy something a couple of steps below the highest processor speed.

I'm not a do-it-yourselfer. I want to do my research up front and tell the builder to build it the way I want. I read the thread on painting the wall for a screen. If I can tell the builder to prep the wall this way and use this paint for $500, buy a screen for $1000, or paint the wall myself for $200 I'm going to tell the builder to paint the wall. If the screen only cost $600 I'm probably going to install the screen so I can avoid potential fights with the builder over the quality of the paint job.

For furniture I'm leading toward 2 rows and seating for 6. The room will be dedicated with no windows. I'm somewhat concerned about soundproofing. It will be a one story house with the bedrooms on the opposite side of the house past the kitchen and great room. I don't want to worry about the neighbors if my 16 year old son turns the volume up too loud. The exterior walls will be brick with 2x6 construction and an R-25 insulation package.

Hopefully that gives somebody an idea of where I'm coming from. Assume I have $8-10,000 to spend for everything in the room including furniture, video, sound, wiring, remote controls, installation, calibration, soundproofing and anything else I haven't thought of. I'd really appreciate any thoughts on how I should expect to allocate that budget.
 
#5 ·
Keep as much space as you can. I wouldn't even think about splayed walls. To get any real benefit,you need at least 1" per foot of length on each wall. That would make the front 46" narrower or about 7'. That causes issues with screen size, speakers too close to walls, etc.

A decent 1080p projector will shoot between 40 and 50% of your budget. But, that's OK if that's your goal. Just be realistic about the audio side and how many seats you'll be able to buy - not to even mention the cost of a contractor to actually build this.

Bryan
 
#6 ·
OK, scratch the 1080p. I don't think I want to consume that much of my budget on the video.

As for the construction costs I'm not counting that since it's part of the new home I am building. Since I'm still negotiating with a couple of builders I can still make changes to basic structural elements pretty easily. I've attached a drawing of the house plan I'm starting from. If I need a foot here or there I can increase the home size or steal a little space from the kitchen/great room. Construction costs are about $55/sq. ft here so making the home a little longer or wider wouldn't be too expensive. By the same token I can make it a foot shorter and have about $600 more for something else. That's why I'm trying to 'right-size" the room.
 

Attachments

#9 ·
OK, scratch the 1080p. I don't think I want to consume that much of my budget on the video....I've attached a drawing of the house plan I'm starting from....
Do you have a drawing just for the HT???? ....If you do, maybe you can post it and get opinions from others expereriences that can guide you to have a nice set up.:yes::yes::yes: ... if you don't have one, It will be a good idea to start planning one.

After looking at the drawing, it seems to me that the room will be narrow and long (mine is 9 x 18 inside dimensions, I'm not counting the thickness of the walls); I have two rows of seats and the space between the wall and the seat is only about 11" in one side only .... in your case it will be around 18" each side to have it centered on the room (depending on the size of the seats :scratchhead::scratchhead:....I think a wider room will be necessary .....just my opinion.

Do you need a projector???? .... What about plasma, LCD, DLP???? .... maybe you can save some money there. I have a 67" DLP, with todays price it costs around 2800.00 .... but if you want a projector, you can also consider a used one to save some money :huh::huh::huh:
 
#7 ·
After some more reading tonight I wonder if I really need to scratch the 1080p or not. Since we haven't even decided on a contractor it will probably be Christmas before this house is finished. Would anyone care to guess where the 1080p pricing might be in 6 months? Do projector prices tend to follow PC pricing with significant sales the day after Thanksgiving and sometime after Christmas?
 
#8 ·
They may fall a little but they're already fallen a lot in this last generation. As for the room size, if you need the money, shortening up to 19' wouldn't be a bad thing but would put more of a crimp on proper seating if you want 2 rows.

Bryan
 
#10 ·
John. the ancient Greeks found a room ratio the length 1.5 times the width and ceiling as high as possible to obtain the best acoustics, that still applies to today . As to a screen , paint your plaster , (dry wall) it saves you a fortune , and there is little difference in quality between that and a 2000 dollar screen , I know because i have done so , and so have my friends . Put most money into good speakers , acoustic treatment to the room can be added later anytime . Get a cheap projector as the projectors are getting better and cheaper every day , latter you can get a crash hot one for bugger all . Hope my suggestions are helpful to you John . Kind regards , Alan .:T
 
#11 ·
John, I'm not sure if you've seen this room mode calculator or not. You should definitely download and play with it, noting the various "golden ratios" it suggests. While it's not hugely important to stick to these ratios, the calculator is also great for room volume: compare yours to the suggested minimum and you'll get an idea of where you stand.

You might also like to check out this viewing distance calculator.
 
#12 ·
I only have one comment about the screen:

I would not paint a screen unless it fell exactly on one horizontal drywall piece in the middle. Drywall and plaster is almost impossible to get perfectly flat. There are usually seams with mud buildup. All this could cause a "speedbump" in the screen, which once you notice, you will not be able to un-notice.

If the screen was across only one board laid horizontally, none of the image would be on the seams, so it would probably be okay, so long as the screw holes were filled right.

And I have never seen a perfectly flat all-plaster wall. What looks flat at a glance and what is flat enough for a screen are very different.

That all being said, I have a $500 fixed frame screen (Greywolf II) and love it. The pull down versions are much cheaper. So you don't have to spend a fortune to get a good screen.

Best of luck.
 
#14 ·
Anthony , I have painted a rough as guts plaster wall , and the picture was perfect once the screen is illuminated , I know it does not make sense , but I have done it and tested it . no difference between that and $2000 screens . don't take my word on it but do it and you will be pleasantly surprised and save heaps no bull. Alan :jump:
 
#13 ·
Agreed. Painting sounds like a great idea and it's relatively cheap - but the imperfections can be really annoying. That said, you can DIY a screen pretty reasonably using matieral from Carada or others. If video is your primary concern, then I wouldn't scrimp on the screen. The best PJ in the world won't help if your projecting onto a sub-par surface.

Bryan
 
#16 ·
I did want to try it when I got my projector, I just had too much on my plate and wanted to just buy it and be done. Maybe sometime in the future.

It probably would not have worked in my case as well. I ended up with the Greywolf II screen because I needed the 1.8 gain to get a good picture with my size and lighting. The 1.0 screen I had as a loaner washed out quickly with any room light (my wife and I like to read or do other chore/hobby things while watching TV, so being able to see a good picture with the room lights up was a must). The 1.8 gain screen really works well for us.

I'm not sure if you can get that kind of gain from painting, but I do remember some expensive paints designed for screens that might work. Name escapes me now, though.
 
#18 ·
I appreciate all of the suggestions. I've been giving it a lot of thought and here's where I'm at for now.

I'll probably buy a screen. I'm a little like Anthony in that I've got a lot on my plate and I rather just have it done. Having the builder paint it probably wouldn't save me much. A paint color change is +$200 and smooth walls are another upgrade cost.

After looking at some theater seating sizes I've decided to add a ft to the width. I've learned the standard room height is 9' so that would give me HxWxL of 9x12x23. I've attached a drawing. While I show it as a riser I'm actually going to have the floor lowered in the area near the screen so the height in that area will be more than 9'. That's so the back of the room where the door is will be the same floor level as the rest of the house. I'm trying to keep things in the house wheel chair accessible for when I get old and feeble. Any suggestions on how much I need to lower that area for a second row of seats to have a good view?

I've also come up with some budgetary numbers and some preliminary ideas for some of the components of the room. The prices for everything except the cabling and the furniture were from web sites that I think are reputable. The cabling was a price from an audioholics.com recommended system and the furniture was basically what was left from my $10,000 budget.

Any additional thoughts on this?
 

Attachments

#21 ·
...I appreciate all of the suggestions. I've been giving it a lot of thought and here's where I'm at for now. After looking at some theater seating sizes I've decided to add a ft to the width... HxWxL of 9x12x23. ... I'm trying to keep things in the house wheel chair accessible for when I get old and feeble. Any suggestions on how much I need to lower that area for a second row of seats to have a good view?...
I think that the room need to be wider (there is only aprox 18" between the seat and the wall) ... I think you need more than that, I have 11" in that space, and sometimes you have to be a contorsionist to get to the second row ..:yes::yes:... I'm assuming that if you have somebody in a wheelchair you will acomodate them in the back row, Right??.

If you make the room wider, you will have more space to a install the speakers, without changing the screen size as the other suggestions ....

I have a riser, it is 14" high ... there is a formula to calculate the height (I don't remember where I got it, but it was on the internet and ask you for distance, height of seat, height of the person that will be seated, height of the screen from floor, etc.) .... I think if you lower the front 14" will be okay ... but maybe you need less than that ...:scratch::scratch:
 
#19 ·
The screen is WAY too big for that seeting distance - not to mention putting speakers all the way out to the wall which will cause tons of bass response anomolies.

Bryan
 
#20 ·
Agreed. If BoomieMCT checks in here, he did a similar thing with his theater. He basically filled the whole wall with a screen because he could and had about 6" a side for speakers.

While the screen is great, it gave him little room to put speakers.

I would only go that big if using an acoustically transparent screen with the speakers all behind it.

That being said, reducing to 120" screen would give you more room for speakers. I'm 8' away from a 92" screen and I can't get much closer without seeing pixelation and screen artifacts (720p projector). 1080p would help with that some (i.e. let you sit closer or have a larger screen).

That being said, I like the design and seat placement.

Good luck and keep us posted!
A
 
#22 ·
Okay, some easy responses first. I think 12' is about all the width I'm going to go with. Since the house is single story it's already getting a little wide for the lot. Also every foot in width adds about $2K to the home cost that I'd rather put into something else. I'm thinking about having an armless recliner in the middle to reduce the width or choosing a design with narrower seats or only doing that in the back row.

Yes any wheelchair seating will be in the back row but hopefully not for many years. My wife and I are both healthy and have no reason to believe we'll need to use a wheelchair we're just planning for that possibility in the design.

As for the screen size, I went to the viewing calculator and tried it out for 12' and 18' viewing distance with a 118" screen. The results are attached. Does that seem more reasonable? The 118" screen seems to fall into the THX seating recommendations. Does that allow enough room for appropriate speaker placement? (107" x 62" outside frame)

For reference, at the theater I usually go to there are three or four rows up front, an 8 to 10 ft aisle, a row of handicap seating and then the main risers start. I hate the front rows but usually like the first row after the the handicap seating.

More questions now -
Are there other tradeoffs for choosing a screen that size? Are there other screens I should consider? While I'll have no windows and complete lighting control I would like to be able to see this reasonably well if I have the lights up for a Super Bowl party. Will this screen/projector combo be OK? Do I need the bright white screen?

Just when I think I'm getting a handle on this I read more postings which generate more questions. That's OK though I'm enjoying the research. Pretty soon though I'm going to have to stop asking questions and contract with the builder. My wife is getting impatient.
 

Attachments

#23 · (Edited)
I'm at the stage of construction where some of the decisions I made at the beginning of our home construction are starting to pay off, and your situation is pretty similar to mine (budget/seating/room size), so I thought I'd chime in:

Not to beat a dead horse, and ignore this if the decision's been made, but I'll throw in one more vote for the wider room. Our first plans showed a 12' x 22' room for the theater, and now that it's nearing completion, I'm very relieved that we increased it to 15 x 22. 12' looked pretty good on paper, but going even a couple feet wider will be well worth the money. Actually, it was my wife who suggested the larger room - She said a few thousand dollars on a fifteen-year loan at a good interest rate to get the room I want is well worth it, since it can't be easily widened later. The extra space not only helped seating access, but surround speaker placement, acoustic treatments, screen width, etc.

If you do keep the 12' width, you might want to incorporate acoustic treatments into the walls and cover those areas with cloth instead of sheetrock. Bryan or Ethan could answer this better, but I think room treatments added to the wall surface might take up space you can't afford to lose. I did the 1st reflection points and front wall that way just for aesthetics and it seems to work well, but I'll probably still add panels later.

My seating is at 12' and 18' and I went with a DIY 124" wide 2.35:1 fabric screen. I did try painting the wall (I've tested screen, lighting, speaker, and seating placement several times during construction:ponder:), and it looked OK, but I wanted to do some lighting behind the screen so I went with fabric mounted off the wall about 4".

One other consideration for screen size is the projector location. I can't have much lighting on in the room because my projector is so far from the screen. My total theater area is 15' x 28', but I built a 15' x 6' equipment room at the back of the theater and my projector is in there shooting through a hole in the wall. With a 10' wide screen and 22' throw distance, I need to keep the room pretty dark for wide-aspect movies. It's not too bad at 16:9, though.

Good luck with your build.

Joe
 
#24 ·
The only problem with incorporating them is that you lose the isolation layer. Realistically, one can properly do a room with only 1-2" panels on the side walls if we can deal with the lower frequencies in the front, back and corners.

Bryan
 
#25 ·
Joe - I doubt if I'm going to add any more square feet to the house. Adding 3 more feet to the wall would add $7640 to the construction cost ($10,620 over the life of that 15 year mortgage). I think I might be better off investing in some of Bryan's room conditioning. I may decide to steal a foot or so from the kitchen/great room area. I am curious about the lighting/projector issue - did you need to place it so far back because of some projector constraint or was it just the fact that you wanted the equipment room back there?

Bryan - I was looking at the Surround Sound diagram in the acoustic primer on your web site. When I try to place a circle around some hypothetical point in the room I end up with the front speakers nearly in the front row (see the new picture attached). I realize that the theoretical often conflicts with the room dimensions. Would I just end up placing them near the front middle and some distance from front corners and try to condition the space to accept whatever geometry that results in?

Can you also give your thoughts on the merits of having some drywall angles like I've shown in the back of the room? I noticed on Ethan's Real Traps site that there was a recording studio with a lot of hard surface angles (picture attached). As for some of your traps what would be a minimal requirement for conditioning a room like this?

I also wonder if something couldn't be done to make some of the traps more attractive. I got a couple of fairly large pictures handing in my living room right now. The frames are about 2" deep. If I had them reframed so there was a couple of inches behind the pictures and no glass could some acoustic material be put behind the canvas to provide decoration and acoustic treatment?
 

Attachments

#27 ·
I am curious about the lighting/projector issue - did you need to place it so far back because of some projector constraint or was it just the fact that you wanted the equipment room back there?
It was mostly for looks. I preferred not to have the projector hanging from the ceiling so I tested how far back I could go without giving up too much picture quality, and selected that distance for the equipment room wall (I did hedge my bets a little and ran a conduit to a ceiling location just in case). All the source electronics and the DVD shelves will be in the back room - again, just for looks.

By the way, good decision in choosing acoustic treatments over room size if that was the trade-off. It was a good catch by Bryan regarding the isolation problems with in-wall treatments. I forgot all about that. In my case, I built the walls out to cover the short concrete stem walls, so I had a lot of room to play with above them. I'll still do other rteatments and bass traps, though.
 
#26 ·
The angled surfaces are a totally different thing in a studio. I'd avoid them if at all possible - it takes away easy places to deal with all dimensions acoustically. Also, do be of benefit, the amount of angle would cause you to lose a tremendous amount of space in the room which you frankly just don't have.

As for the circle, you have to extend out the angled lines to your situation - don't worry about the radius per se.

Bryan
 
#28 · (Edited)
I've seen a couple of references to acoustically transparent screens. Are those significantly cheaper or more expensive than other screens? I've seen theaters built with space behind the screen before but I never realized this was for the speakers. Are there audio advantages or disadvantages to this setup?

I've been trying to figure out where to run wires in the room. I think I can figure out where the speakers would go. I assume that, given my narrow room the back center would be the best location for the equipment rack (saving the corners for potential bass traps). I'm not sure how to accurately place the projector without putting it up and seeing how it looks. I know it will depend on the projector itself, my desired screen size and the screen brightness. I recently read a review on the Optoma HD80 that was pretty impressive. Does anyone have any experience with this projection calculator from Projection Central? http://www.projectorcentral.com/Optoma-HD80-projection-calculator-pro.htm

I like it because it lets me see how the different components affect each other. It says that the results are based on numbers provided by projector manufacturer so I have no idea if it is accurate.

I'm also wondering if there is some way to sound insulate the projector without causing overheating problems because some of the placements that I come up with are right over the viewing area.

What are the acoustical costs of ceiling mounting some of the speakers? My sister has a new baby on the way so ceiling mounting would have an additional childproofing benefit.
 
#29 ·
Whew, that's a lot of questions, Owl :bigsmile:

Regarding the AT screens, certainly they're more expensive. From my research, most are plasticised fabric perforated with little holes: this reduces the gain a little on the screen, but allows most sound to travel through (apparently there is a slight treble attenuation -- not a bad thing probably, as most movie soundtracks are a bit bright).

One brand -- Screen Research -- says they have a special woven screen that hardly loses any brightness, but can still allow the sound to pass through. They also cost a huge amount compared to regular screens. Incidentally, one of their fixed screen range is *curved* to suit the projector's throw... very snazzy indeed.

Regarding projector placement, I intend on building an alcove in a drop-ceiling bulkhead, which should isolate the project from the audience a little without reducing airflow. You should certainly NOT put insulating materials directly around the projector, or you'll be buying new bulbs each month as they burn out (or a new house after it catches fire!). The reason projectors are noisy is the fan keeping them cool.

Finally, ceiling monted speakers are getting better all the time, but a lot of HT purists think they place the soundstage a little too high. Nevertheless, it's again a case of "you get what you pay for"... better quality ceiling speakers will usually perform better than cheaper wall-mounted speakers.
 
#30 ·
John,

I would avoid the in celing approach. Remember, the higher frequencies above 500 Hz are more linear than lower frequencies which are spherical. So, your speakers, being aimed down, would fire the higher frequecies right at the ground. This would limit the spacious surround envelopment. Plus, you would not get the reflections off the surrounding walls which add to the spacious environment. You want to be able to have some flexibility with your LCR to help alleviate SBIR (speaker boundary interference reflections). I would reduce the size of the screen to say around 100" maximum. At the distance you have your front seats placed at, 100" should be more than enough to project an optimum field of view. If you can't widen your room, I highly suggest you eliminate two seats. With the distance from the side walls you have specified, you are likely to end up with a "exit door" effect at those outlying seats. Basically, the center front is your money seat and the only seat that is relatively optimum in your room with your current design. In addition, subwoofer placement will be limited since much of the side aspect of your theater is taken up by seating. Also keep in mind that placing seats side by side is not usally the best way to go either since you have room modes along the width of your room as well. Remember, I am only a few short hours way! :bigsmile:
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top