Room Dimensions? (1 Viewer)

[Brad_Russelburg]

I am getting ready to build a new home and I would like to go ahead and have the walls of the home theater room framed out. The theater room is going to be located in the basement and I plan to start on the theater room in a couple of years. Since the walls framing will be permanent I need to get the dimensions correct. I was thinking to make the room 18' X 20' is that a good size or should I do something different? I plan to have a 100" projector for video & audio is going to be high end (Not sure what yet) My budget for the audio & video equipment is $20,000 (not including the rooms construction) so I defiantly want to design the rooms dimensions properly. I would hate to spend that kind of money on the audio system and it not sound its best because of room size.

Any suggestions from experienced home theater enthusiast would be greatly appreciated.

 

[Brad_Russelburg]

I am getting ready to build a new home and I would like to go ahead and have the walls of the home theater room framed out. The theater room is going to be located in the basement and I plan to start on the theater room in a couple of years. Since the walls framing will be permanent I need to get the dimensions correct. I was thinking to make the room 18' X 20' is that a good size or should I do something different? I plan to have a 100" projector for video & audio is going to be high end (Not sure what yet) My budget for the audio & video equipment is $20,000 (not including the rooms construction) so I defiantly want to design the rooms dimensions properly. I would hate to spend that kind of money on the audio system and it not sound its best because of room size.

Any suggestions from experienced home theater enthusiast would be greatly appreciated.

 

[Jonathan Smith]

You might want to browse through some of this article written by Ethan Winer to learn a little bit about room acoustics if you're not familiar with the basic concepts. Here are some "ideal" ratios of height to width to length given in the article:

H x W x L
1.00 x 1.14 x 1.39
1.00 x 1.28 x 1.54
1.00 x 1.60 x 2.33

It is definitely worth the effort to consider the acoustics of your space ahead of time, especially if you have a good amount of flexibility in your design!

Cheers,
Jonathan

 

[Jonathan Smith]

You might want to browse through some of this article written by Ethan Winer to learn a little bit about room acoustics if you're not familiar with the basic concepts. Here are some "ideal" ratios of height to width to length given in the article:

H x W x L
1.00 x 1.14 x 1.39
1.00 x 1.28 x 1.54
1.00 x 1.60 x 2.33

It is definitely worth the effort to consider the acoustics of your space ahead of time, especially if you have a good amount of flexibility in your design!

Cheers,
Jonathan

 

[Joe Rosiak]

I appologize in advance for being a bag of rocks.

So I read an article in this Months Home Theater Builder mag, that stated the formula of:
1.7 X Ceiling height = length
1.7 X Length = width

How does the formula you supplied work?

 

[Joe Rosiak]

I appologize in advance for being a bag of rocks.

So I read an article in this Months Home Theater Builder mag, that stated the formula of:
1.7 X Ceiling height = length
1.7 X Length = width

How does the formula you supplied work?

 

[Ethan Winer]

Joe,

> How does the formula you supplied work? <

The goal is to have the three dimensions be as unrelated to each other as possible, to space the room modes evenly and avoid coincident modal peaks. Have a look at my Acoustics FAQ Jonathan linked to. In particular, see the section that explains room modes, and also the sidebar that describes the ModeCalc program you can download.

--Ethan

 

[Ethan Winer]

Joe,

> How does the formula you supplied work? <

The goal is to have the three dimensions be as unrelated to each other as possible, to space the room modes evenly and avoid coincident modal peaks. Have a look at my Acoustics FAQ Jonathan linked to. In particular, see the section that explains room modes, and also the sidebar that describes the ModeCalc program you can download.

--Ethan

 

[Jonathan Smith]

My understanding of the numbers that I reproduced is that they are the result of a great deal of research and modeling. That being the case, I don't think there's an easy way to explain how they work.

Home Theater Builder has also quoted the same dimensions that I quoted in another article. It sounds like they are pretty well tested and recommended.

I have also heard recommendations similar to the formula you gave using the so-called "Golden Ratio" that appears all over the place in nature (1.618) rather than 1.7. For typical listening room/theater dimensions, using that rule of thumb also spreads out the room modes pretty well.

 

[Jonathan Smith]

My understanding of the numbers that I reproduced is that they are the result of a great deal of research and modeling. That being the case, I don't think there's an easy way to explain how they work.

Home Theater Builder has also quoted the same dimensions that I quoted in another article. It sounds like they are pretty well tested and recommended.

I have also heard recommendations similar to the formula you gave using the so-called "Golden Ratio" that appears all over the place in nature (1.618) rather than 1.7. For typical listening room/theater dimensions, using that rule of thumb also spreads out the room modes pretty well.

 

[ChrisWiggles]

There are quite a few recommended ratios, this is a very useful spreadsheet with that info contained in it:

http://www.rmmpnet.org/members/ChrisW/ControlRoom.html

 

[ChrisWiggles]

There are quite a few recommended ratios, this is a very useful spreadsheet with that info contained in it:

http://www.rmmpnet.org/members/ChrisW/ControlRoom.html

 

[Gerry S]

Based on all these formulas, it seems your room size is strictly mandated by your ceiling height.

In my case I have 8' ceilings. I have access to an open area of 18' x 26' to build a theater. Based on the ratios, I would have to have a small room even though I have alot of available space.

Any comments on how ceiling height dictates room dimensions? Can't one build a 8'x17'x23' room and add treatments to compensate for deviating from the golden ratios?

 

[Gerry S]

Based on all these formulas, it seems your room size is strictly mandated by your ceiling height.

In my case I have 8' ceilings. I have access to an open area of 18' x 26' to build a theater. Based on the ratios, I would have to have a small room even though I have alot of available space.

Any comments on how ceiling height dictates room dimensions? Can't one build a 8'x17'x23' room and add treatments to compensate for deviating from the golden ratios?

 

[Pus Suchre]

Just a note, but a fellow complained (I believe in this forum) about having his room framed- but waited several months to put up the drywall. In the intervening time, a fair number of his studs warped and needed to be replaced.

 

[Ethan Winer]

Gerry,

> it seems your room size is strictly mandated by your ceiling height ... Based on the ratios, I would have to have a small room even though I have alot of available space. <

You bring up an excellent point. In most home-sized rooms the ceiling is the limiting factor that prevents getting even close to an optimimum ratio. It always makes more sense to go with the larger space than a "perfect ratio" because that helps in other ways. What nobody ever seems to mention is that all room modes are not equally important. Assuming the loudspeakers fire the long way into the room, down the length, that length is much more important than the height. So in my opinion it's a big mistake to reduce the length just to get a good ratio.

> Can't one build a 8'x17'x23' room and add treatments to compensate for deviating from the golden ratios? <

Yes, absolutely, and I personally witness this done succesfully every day. If you haven't read it, see the Acoustics FAQ, second in the list on my Articles page:

www.ethanwiner.com/articles.html

In particular, see the section on room modes, and the sidebar that describes the ModeCalc program you can download for free.

--Ethan

 

[Gerry S]

Ethan:

Thanks for the link. I'm looking forward to studying the information at your site.

-Gerry