Someone told me my room is perfect for acoustics

[ObsceneJesster]

My room lay out came up in discussion over at AVS and wanted to get some more opinions on it. A couple guys over there told me my room is perfect for Home Theaters and I wouldn't have to do much to it. If you guys don't mind, I would like to get some more input from people who are more knowledgeable than myself when it comes to Home Theater.

My dimensions are 18x16x8. I have one couch which is located in the middle of the room and 12 feet away from the front wall. The only other piece of furniture in the room is a cocktail table made of iron and stone sitting in front of the couch. It is a basement so 90% of the room is under ground and surrounded by concrete. The wall make up staring with the outer shell is concrete, insulation, sheet rock, insulation and then dry-wall for the inner layer. The room has no windows and is carpeted.

What I am wandering is if there is anything else that wouldn't cost an arm and a leg that I can do to improve room acoustics?

 

[jonnythan]

Rectangular rooms are NOT good for acoustics - especially ones that close to square. There's a reason that music halls have splayed walls, sound absorbing panels, etc.

It's nothing terrible, but an empty room with drywall or concrete on 5 sides and a metal table in front of the main listening position is going to need a fair bit of treatment to sound good.

 

[ObsceneJesster]

Rectangular rooms are NOT good for acoustics - especially ones that close to square. There's a reason that music halls have splayed walls, sound absorbing panels, etc.

It's nothing terrible, but an empty room with drywall or concrete on 5 sides and a metal table in front of the main listening position is going to need a fair bit of treatment to sound good.

It is not a perfect rectangle. I should have added that there is a cubby hole about 4 feet deep and 3 feet wide on the back left corner. In the front left part of the room where the door is, there is another foyer type area that is about 5x5. I understand that I have to add things to the room but I just don't know what I should add.

Maybe I should have explained things better in my original post. What I meant to say is not that my entire room is perfect but that the material in the walls surrounding the room is ideal and that I have a good starting point.

 

[jonnythan]

It is perfect in the way that a blank canvas is a perfect work of art

 

[ObsceneJesster]

It is perfect in the way that a blank canvas is a perfect work of art

I don't get it.

 

[highfigh]

It is not a perfect rectangle. I should have added that there is a cubby hole about 4 feet deep and 3 feet wide on the back left corner. In the front left part of the room where the door is, there is another foyer type area that is about 5x5. I understand that I have to add things to the room but I just don't know what I should add.

Maybe I should have explained things better in my original post. What I meant to say is not that my entire room is perfect but that the material in the walls surrounding the room is ideal and that I have a good starting point.

Here ya go-
http://www.realtraps.com/modecalc.htm

I just ran your room in the mode calculator and it really is good, until about 200 Hz and the frequencies where the response takes off aren't hard to tame. If you reduce the first reflections, it should be very good, up to 500Hz.

 

[ObsceneJesster]

Here ya go-
http://www.realtraps.com/modecalc.htm

I just ran your room in the mode calculator and it really is good, until about 200 Hz and the frequencies where the response takes off aren't hard to tame. If you reduce the first reflections, it should be very good, up to 500Hz.

Cool, where is the room mode calculator at?

 

[ObsceneJesster]

Here is a floor plan of what my room looks like. I just added another couch to the right wall which should help a little.

http://pl.an/tv9621

 

[highfigh]

Cool, where is the room mode calculator at?

It's close to the top of the first section on the home page.

"NOTE: ModeCalc is not meant to show how to treat an existing room. For treatment advice please see:

Acoustic Basics
Placing RealTraps

Click HERE to download the Windows version of ModeCalc - our Graphical Room Mode Calculator (1.3 MB) that has a greatly improved interface and offers more information than the original DOS version below.There's nothing to install - just Unzip the files into any folder, then run the modecalc.exe program file."

 

[Tubamark]

Is there an existing ceiling, or just joists at this point?

-- Mark

 

[ObsceneJesster]

Is there an existing ceiling, or just joists at this point?

-- Mark

There is a dry-wall ceiling that is 8 feet high. The ceiling has a 3 foot gap between it and the first floor. I have easy access to the space between so I am thinking about spraying some fiberglass insulation in that 3 foot gap. If I do, I will probably fill two feet of it and pack it tight. This will give me about a 1 foot gap between the insulation and the first floor.

I also forgot to mention I have 2 bulk heads that extend 1 foot down from the ceiling. The one bulk head covers the entire front wall and the other bulk head covers most of the left wall.

I already ordered some absorbers/traps that I will mount on an angle between the ceiling and the bulk head if you know what I mean. Two traps on the front bulk head and one trap on the left bulk head.

I don't know what I am going to do with the rear wall yet. I am thinking about mixing it up with traps and wooden diffuses.