Cedar Creek Cinema II

[Sonnie]

Welp... it's that time to start planning.

I have a lot of space to work with since this will actually be an addition to the back side of our home.

There use to be a formula for calculating the proper size of a home theater room... anyone recall it?

I would probably like to have something about 16-18' wide by 24-26' deep... somewhere in that range or close to it.

Keeping in mind a 4 recliner section is about 12' wide and a 5 recliner section about 15' wide. Not sure what I will do there yet, just a thought to keep in mind for the width.

[salvasol]

Sonnie wrote:

There use to be a formula for calculating the proper size of a home theater room... anyone recall it?

I would probably like to have something about 16-18' wide by 24-26' deep... somewhere in that range or close to it.

I think it was 1:1.6:2.4 (9'x14.5x21.6)

[salvasol]

I did a search ....and almost got it right

Height Width Length
1.00 1.14 1.39
1.00 1.28 1.54
1.00 1.60 2.33

Table 2: The ideal room has a ratio of height, width, and length similar to one of these

Here is the link to full Article

[Sonnie]

That's a pretty good read there.

New dimensions and layout pics in this post.

[Space]

Here is an article more related to the room ratios and volume of room.

http://www.acoustics.salford.ac.uk/a.../?content=best

It was a link taken from this page;
http://forum.studiotips.com/viewtopic.php?t=685


All heavy reading but all worth the time, imho.

[Sonnie]

They seem to agree with each other.

I used the Room Mode Calculator we have here at the Shack and compared a few sizes.

The far right is what we had in our previous dedicated room... 8.5 x 11.5 x 19.5.

From what I understand, you want the as evenly spaced out as possible, but also the more you have the better.... you do not want them too far spaced out. The first column appears the best.

[robbo266317]

The only issue I would have with the first one is that their are six close groups.
1) 57, 62, 64
2) 88, 89
3) 125,127
4) 170, 173
5) 188, 191
& 6) 232, 234

The second one only has two close groups with the rest spaced out.
1) 70, 72
2) 141, 144

[Sonnie]

I need to try to figure out a good ratio with 9' height if possible. It seems hard to get that height with enough width and depth.

[robbo266317]

What is your maximum & minimum widths available.

[Sonnie]

It will be an addition, so I can do pretty much whatever I want. I was trying to stay in the 9' high x 16-20' wide x 23-27' deep. Somewhere in there. The 10' x 16' x 23.4' may end up having to work, but the height could end up being an issue. I would rather not have to deal with it and probably wouldn't have to if I can go with 9' height.

[thewire]

24 X 15 looks pretty good to me for a 9' ceiling. That isn't when I am using any specific ratio, just looking at the calculator.

[robbo266317]

I will have a better look tonight but have a look at 24 x 21 x 9.
No problems below 150 Hz. Also if you are going for a vaulted ceiling it's harder to predict what that is going to do to the response.

All I do is choose the dimension that i prefer eg width or height and paste it into the spreadsheets here: http://www.acoustics.salford.ac.uk/a...oom_ratios.xls using the formula. 9.0 =D3*B3 =D3*C3 and then search for likely candidates. (That is with 9.0 in cell D3 and the two formulas in the next two cells)

[Sonnie]

15' would be too narrow... I need 16' and would prefer 17'.

I have read in several studies that multiples of each other is the worst you can do, but plugging in 21 x 24 x 9 does not look too bad... although that is a bit wide and a tad short for what I would like.

[thewire]

I was recommended not to exceed a volume of around 4590 cubic feet. It is a challenge to fill all that space with sound.

[robbo266317]

A fair compromise can be had by a room of 25 x 18 x 10
Which comes out at 4500 cu ft. and only has a minor group at 90Hz.
If you plug the figures in here:- http://www.bobgolds.com/Mode/RoomModes.htm
it also shows there are only minor problems.
For a graphical display of room node ratios check out here:- http://forum.studiotips.com/viewtopic.php?t=3148
hth

[Sonnie]

I really do like that size... especially the 18' wide.

I will investigate it along with adjusting 4-6" one way or the other on each.

[robbo266317]

Found another great site which lists the "2nd best room dimensions"
http://www.acoustics.salford.ac.uk/a.../?content=best
The file link is:-
http://www.acoustics.salford.ac.uk/a...econd_best.zip
It's a zipped Excel file, set an autofilter and you can search all the ones close to 1.8 (ie 18 feet)

[Sonnie]

I have been reading over all of these sites and wow... my head is spinning.

[Wayne A. Pflughaupt]

Sonnie wrote:

Welp... it's that time to start planning.

I have a lot of space to work with since this will actually be an addition to the back side of our home.

So you gave up on the "family room theater?"

Regards,
Wayne

[Sonnie]

You are up late.

Yeah... I think that will end up being too small and it looks like Chelsea may never leave the house. She's home grown and rooted for some reason... Plus... Angie is none to crazy about all this bass in the great room, and it is worse when you are in the family room, so the great room will probably be bad if subs are in the family room.

With a dedicated room added on to the back side of the garage, entrance from the now back door of the garage, it should really be silent even with the IB system. There will be no openings from the HT attic to our current attic. Access into the attic of the HT room will be from within the equipment room by way of a ladder. The addition will be bricked same brick as the house... as well as roof the same, so it will look like a part of the house.

This way I should be able to do it right... the right size... like I have always wanted. It will be the last big thing I do I hope.

[Rodny Alvarez]

It will be the last big thing I do I hope.

[Wayne A. Pflughaupt]

Sonnie wrote:

You are up late.

Yup - working nights this week...

Yeah... I think that will end up being too small and it looks like Chelsea may never leave the house. She's home grown and rooted for some reason...

Ya might want to increase her dowry - hee hee...

It will be the last big thing I do I hope.

I'm with Rodny - Maybe if you were 68 or something, but you're to young to be talking like that!

I do find this a bit curious, since you told us when you tore out the other one that you are losing interest in movies these days. Change of heart, I guess?

You doing the work yourself? I mean, you and Rodny?

Hopefully this time you'll stick in a window unit? Maybe some lighting bright enough to read the spines of DVDs?

Regards,
Wayne

[Sonnie]

You know... I didn't realize just how much I would miss it after I took it out. Having built the sub and setting everything up for the great room, I really miss it. I also can't get the same bass I had in the HT room. Too many things rattling... and the wife is complaining, etc., etc. It's mainly an excuse to do it right and have some fun.

Funny you mention Rodny... another Rodny who has horses on our property and does framing is planning to help me frame it up.

I don't imagine there will be any window unit... it will be a separate central unit, probably a one ton unit.

[Sonnie]

Well... BIG time changes!!!

Angie decided she did not really want our back yard space taken up by the addition and I told her the only other alternative was going to be taking the entire garage. She said she thinks she would rather do that and build on a carport for the cars, which will be a whole lot less expensive. No slab to have to pour... it is already there, even for the carport. No bricking to do... less overall construction work. This should save us a good $10-12,000. Figuring the savings even made us both agree the garage is the ticket. So back to the garage we go, but a LOT different than before. It will be larger and it will have its own 1.5 ton central heating and cooling unit. I will wall off and do my best to seal off the attic space above the garage to help with the low base, which was never that bad... it sounded like distant thunder on movies like WOTW... and then only during the extreme bass scenes. However, if I want to do an IB system, I probably need to seal it off with a 6" wall and insulate it really well. We were already going to insulate the entire attic after having our duct work completely overhauled. I'll seal it and install a solid door, which should help a good bit.

The biggest drawback to this is I am limited on the size. 8.5' height is all I will get after carpet and another layer of sheetrock on the ceiling. It will only be about 7.5' high for the 10' of riser in the rear. The width can range from 17' minimum to as much as 18.5' maximum... then the depth can be 23', 23.5' or 24'. 23' is the minimum I can tolerate with my plans and the garage is only 24' wide... so that has to be the max. The drawing below show 8.5' x 18' x 24', but I figure I will need to adjust that as best I can for room modes. Not much to work with, but this will definitely help monetarily and I might can spend a bit more on my front speakers.

The other minor drawback is I will have to build an equipment cabinet, but that is not a biggie because I have a lot more room to work with than I did with our previous dedicated HT room. This will get done much quicker than I expected now.

[thewire]

I was trying to convince my family we needed to park under the theater during contruction. Congrats on having a better space to work with!