Urgent : Help with Room Acoustics

[rahulsinghania]

Hi,

I am setting up a dedicated home theater room of 220 sq ft. I have purchased my speakers from POLK audio and have ordered for an EPSON tw6100 projector However, now i need help for Room acoustics.
I am planning to use rockwool panels on adjacent walls and cover it up with Knotty Pine Wood. I have been told by someone that pine wood also has sound absorbing properties. Please let me know if it is fine or should i try another way of getting the acoustics done.
Please help .. its urgent..

 

[Bharathram]

Rahul
Are you taking help of an acoustic consultant or planning to do it yourself? The reason why I am asking is because I am also looking to setup one.

 

[rahulsinghania]

I am doing it myself. Read articles on various forums and had a discussion with couple of people. The best option i liked was to get a rock wool base in the wall and cover it up with pine wood with some gap between each plank.
But i want someone from the forum , familiar with acoustics, to give me a further suggestion on this.

 

[john_k_antony]

I did a dedicated HT room all by myself with the help of my carpenters and electrician who didn't have any experience in building a HT room before. But we all thoroughly enjoyed the whole experience.

Here it is - http://www.hifivision.com/home-theater/46258-yet-another-dedicated-home-theater-build.html

Thanks,
John.

 

[rahulsinghania]

Amazing Room John..
Could you let me know what size of the screen should i go for for 16:9 aspect ration on a 9'4" wall out of which 2' would be used by speakers and also for framing did u just got the out frame made or did u put a plyboard behind the screen?

 

[koushik]

Room area doesn't say much. Let us know the room dimension to get the room mode. Then we can work on the room acoustic from there.

 

[john_k_antony]

Amazing Room John..
Could you let me know what size of the screen should i go for for 16:9 aspect ration on a 9'4" wall out of which 2' would be used by speakers and also for framing did u just got the out frame made or did u put a plyboard behind the screen?

Screen size should be derived based on the available wall width and seating distance. There are formulas that help you with the MAX screen size possible based on the viewing distance and you can work "down" from the max size to fit the wall width and height.

We just built the outer frame with ply and also added vertical bars to reinforce the outer frame from bending. When you give the specs to an experience carpenter, he can help you with what kind of reinforcements that are need to keep the outer frame from bending. Then we stapled the screen material on the outer frame with heavy duty staples while two guys stretching the screen material from either side. Please look at my post for the actual spec of the screen frame. We didn't have to put plywood to cover the entire screen area.

If you are doing the DIY frame, make sure that you leave 3" or 4" outer border and cover the border with a black velvet cloth. Also make sure that the actual screen is 1" inside the border so that the border just projects out. This adds to the overall picture quality and also the decor.

-John.

 

[rahulsinghania]

Thanks John for the detailed reply.

Koushik i am attaching the layout of the room . Its 9'4" by 23'1" ft . Please help

 

[koushik]

Koushik i am attaching the layout of the room . Its 9'4" by 23'1" ft . Please help

I guess the height of the room is 10' or 8'. In both case it is room with decent mode distribution. 8' is better even. Your room mode is 24.47

You are lucky that your room is quite distributed at the lower bass area. You will get away with mid-bass traps which are easy to handle than frequencies lower than 200Hz.

There are some peaks at 110-120, 170, 180 Hz and almost everywhere after that esp. after 225 Hz.

- I would start with two 4" thick glasswool panel on the either side at the first reflection point hanged 2-3" away from the wall keeping some air gaps.

- A similar trap on wall behind the speakers. As the room is quite long, try to build bigger panels like 4x4 ft.

- And 2 (or more) corner traps at the corners. Preferably behind the listeners. There are couple of peaks at 55-60Hz. Treating all 4 wall-wall corners are recommended.

- Thick curtains on doors and windows, a must.

- Carpet atleast on the first reflection point on the floor is much desirable.

Remember, there can't be enough bass traps. It is "more the better" thing.

Good luck!

My 2 paisa.

 

[shkumar4963]

One advise. Get REW and miniDSP. It will fix whatever you can not fix by room conditioning

 

[rahulsinghania]

Thanks Koushik .. ll definetely follow what u said.. Also plz suggest what should be the distance between ceiling and the projector. I want to ceiling mount it and also i need to purchase a ceiling mounting Kit.