WOW! A lot of great feedback - highly appreciated! This will be a long post, but let's see if I can answer all the great questions
Originally Posted by javeryh
14'-9" doesn't seem like enough for room within a room AND 2 rows of seats. My room started at 23' long and by the time I was done soundproofing and everything I just barely fit 2 rows. Your first row looks to be WAY too close to the screen. I think in the long run you'd be better off trying to fit 4 seats in one row instead of compromising all over the place.
Multi-Rum sounds delicious by the way!
Haha never looked at the word that way. However, 'Multi-Rum' directly translates to 'Multi-Purpose-Room', so not as delicious as you could have wished for
Originally Posted by Tedd
First row viewing angle isn't realistic. Front row viewers won't be able to take in, all of the screen. Front row viewers' eyes will jump around the screen and I expect the front row won't see much use. Front row ears look to be dead center of the length of the room, and there's a lot of nulls and peaks there. uF is rated for 9' viewing distance and XD is something around 10.5', to minimize seeing the screen weave. Please see my response to jjcook below.
Front row speakers are way too high. Plus you ideally want the speakers to be 6" off the backside of a woven AT screen, so
there's no timbre shifting. I've never really understood this. Is the AT screen any different than a conventional speaker grill which sits very close to the drivers? Besides, as I will be doing DIY speakers, I plan on being able to deal with any timbre shifting in the crossover.
The screen is boxed in, with many near boundary surfaces. I plan on using black fabric panels all around the screen, including the "box" it sits in. Hopefully that will avoid any screen glare issues, which I assume you are referring to?
Will those subs cause the screen to vibrate/ripple? After what I can read from other IB sub owners at AVS and the Cult it shouldn't be an issue. By having the drivers facing each other, the mechanical forces should (pretty much) cancel each other out.
Why waste space for a baffle wall, when there's no space to waste? Not needed for the speakers throw distance to play reference level. The main reason for the baffle wall is to have the LCR speakers behind the screen - especially the center. In the past I've had the center speaker below the screen, and it always bothered me that the sound was not coming from the "right" place. So when I started designing the theater I knew I wanted a baffle wall. The IB sub is a secondary priority, but something I've always wanted to try.
Two rows of seats in 15' of depth. That is very tight, and how does the second row not end up right on the back wall? Seating on the side wall and I expect will be buried in the back corner. I have tried explaining the reasoning for my seating distances further down in this post. You are right though, that the back side seat will be buried in the corner. However, I might as well use that space for seating than just empty space.
Covering the gear is fine, so there's no distracting electronic displays visible, but is there any plan for proper ventilation for the gear? Yes, I will be using silent fans to exhaust the hot air into the return of our ventilation system.
And what is the HVAC plan to cool a small room with six bodies, pj, av gear? What about adequate air changes to make sure the room doesn't become stale? All the AV gear and PJ will vent directly into the return of the ventilation system. The room itself is roughly 1400 CF. Assuming that I would need to exchange air six times per hour leads to 1400CFx6/60min = 140 CFM. I plan on installing 230 CFM silent fans in a push/pull configuration pulling fresh air from the intake and pushing hot air into the return. These will be placed in the soffits in order to minimise noise, and I can possibly run them at lower RPMs as well.
Thanks a lot for taking the time to post so many great questions, Tedd! I've tried answering in blue
Originally Posted by DavidK442
I have modeled things on the computer before that seemed reasonable. However after mocking up the walls with pinned sheets the claustrophobia set in and I quickly abandoned my crazy rat maze plans. I suggest you do the same.
I have tried projecting a movie onto the wall to see what size I would be comfortable with, and I realised that I prefer a fairly close seating distance. I also always choose a seat in the front half of the theaters - I like the extra immersion.
Originally Posted by Tedd
So, are you actually going to fill those six seats? Or could you get away with less seating and one row of seating, to properly accommodate a big screen?
There's lots of really nice European design rooms that are smaller, and you don't need to cram a small room with things like soffits, and columns.
Why 4x 15" drivers in a small room? (Guilty of this myself, and it's insanely overkill.)
I hope to be able to fill all the seats from time to time - especially with friends, family and the neighbouring kids. I host a decent amount of movie nights and events, so maximising seating is a priority. If I overestimate I can always get rid of the front row and install more luxury seating in the back. But it is a very good suggestion and something I will be evaluating once I've gotten some hours on the projector
Totally agree, I will not try and cram columns in there. I will though install a soffit for lighting, ventilation, cables and hiding the projector (for noise reduction).
4x15" drivers is definitely overkill!
However, I know I want dual subwoofers in the room for better bass response. If I am to install an IB sub using 2x18" drivers then I'll have to build them facing out into the theater (and not each other), which means that the false wall would need to be massively re-inforced to cope with the mechanical forces from the drivers. I guess the alternative is to use some sort of box subs, but since I want the false wall for the center speaker anyway, I can put an IB sub there as well. And by having this much overkill I imagine I would never need to upgrade to any other subwoofer
Originally Posted by jjcook
Some feedback on the 9' viewing distance:
My room is only 9'11" deep so I'm fairly close to the screen. I had originally went with a 100"-wide 2.35:1 screen for a ~2.4x ratio of viewing distance divided by screen height. It is a very comfortable size/viewing angle but was not enough for me; along with other room upgrades I'm moving to a 120-wide 2.0-aspect screen which from initial testing (before tearing the room up) was the compelling immersion that I was looking for. That said I am building a 4-way masking system so that regular tv quality content / poor quality content can be shown at a more modest size
Exactly my thinking as well. I have tried different screen sizes and found that I like to sit fairly close to the screen for better immersion.
My seating distances will be ~11' for the back row and ~7' for the front row. The back row will be my primary seating position as this will also put my ears and eyes at a better level with the center of the screen. Assuming a 47" high CIH-image this equates to 2.8xSH and 1.8xSH for the two rows, which for the second row at least, seems ideal to for my taste. When the front row is in use, I plan to zoom in using lens memory to get a slightly smaller screen size. I will start with a 2-way DIY masking system, but later on I might upgrade to a 4-way DIY masking system if I find the need when zooming in.
These distances (when taking the depth of the false wall into account) should put my seating distances at roughly 0.2xL and 0.45xL (measured from back of the room), which accordingly to the excellent presentation by Anthony Grimani in Home Theater Geeks Episode 177 and 178, should avoid any major peaks or nulls in the response - fingers crossed
Originally Posted by Tedd
That's one theme I often suggest. The subtraction of seating and their cost, might very well be budget for other luxury things like masking. Pretty much everybody reaches for seating numbers for their room, thinking those seats will be filled most of the time. But will they?
I expect jjcook isn't talking about a woven AT screen though, regarding a 9' viewing distance. Screen weave on bright scenes, with shorter viewing distances, with an AT screen, can become a big distraction.
I would second David's suggestion of a quick mocking up of the space, before building anything. I got a huge reality check years ago, when I did this.
As mentioned above, I will try an re-evaluate the need for two rows after some time using the theater.
Great point on the woven AT screens, Tedd! I will need to investigate this more.
Originally Posted by jjcook
Actually there are a few options for AT screens that are a reasonable choice for 9' viewing distance (Chris -- see fabric thread linked in my sig for more details); Milliskin Spandex, Dreamscreen V6, DT Screens all performed very well on bright panning snow boarding content from Art of Flight at 18ftL which is the ultimate torture test for AT screen weave visibility.
I do admit its not as perfect as a Stewart 100 but given my room size I can't go non-AT even if I wanted to -- so for me its a tradeoff costing some visual quality but I do gain correct placement of LCR audio which I also value.
A third vote from me on this. Chris should also get AT fabric samples (get large ones not the sheet-of-paper size) to test out weave visibility for himself.
Awesome jjcook! I will definitely be checking out your tests of different AT screen materials.
Originally Posted by Silva741
If you really need two rows the best solution is probably to forget about having an AT screen. Having the front speakers visible is perhaps not as cool looking as having an AT wall, and the audio from the center speaker wouldn't be optimal, but that would allow you to have more seats.
As stated above in the reply to Tedd, it is a high priority for me to have the LCR (especially the center) speakers behind the screen, even though it means I have to compromise a little on screen distance
Originally Posted by jjcook
If you go with ~in-wall speakers then you won't lose any (or much) depth going with an acoustically transparent screen. If you plan to go forward with the pseudo-infinite baffle in a false wall then you probably have the space to do your LCR as DIY as well as you indicate. Just make sure to get the boundary step compensation correct.
I will not be going for in-wall speakers. Instead I will design the DIY speakers for infinite baffle placement.