# Dedicated movie room, need help with acoustic treatments



## pfp (Feb 13, 2011)

I'm almost done with my dedicated movie room and desperately need help with acoustic treatments. I don't know terribly much about the subject but I have been reading up for the last month or so. All I'm really looking to do is pick the low hanging fruit - nothing fancy. I want to handle the basic stuff that's easy, economical, and will hopefully give me a fair sound improvement. 

This is my plan so far but I'm completely open to any advice that can be offered.
First make "superchunk" type bass traps (17 x 17 x 24) using either 703 or mineral wool. Since the entry to the room is in one of the corners I will only be able to do this in three of them. The next step in my plan is to make 24 x 48 x 2 panels for the side and rear walls. As you can see in the drawing below (light blue) I'm probably going a bit overboard on them. I suspect I should make some for the ceiling too but I'm not so sure about hanging them, especially with the ceiling fan which will be on full speed. For the large window I want to do some type of drape to cover the entire thing. I'm just not sure what the best material might be or if I should hang any panels in the window opening behind the drape.

Here is the room:
_Note: The rear and surround speakers will be mounted on the walls near the ceiling._









































































Thank you
paul


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## bpape (Sep 14, 2006)

Good basic plan. Just a couple of suggestions.

Curtain on the window - good thing to balance the higher frequency absorption on the opposite wall. Use heavy material and get them long enough so they hang full even when closed. Use a good backing that will also do a good job of light control.

Front wall - cover this entirely with 2" 703 in addition to the chunk absorbers.

Skip the 2" panel in the rear opposite the door.

Make the rear panels 4" thick instead of 2" to get some better bottom end control in the length opposite the screen.

Bryan


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## Crossblade (Jul 21, 2010)

Having in mind this is a *dedicated HT room*, can you make acoustic panels that are attached/hanged on the right wall in front of the window ? This way you will get very good symmetry. 

If you can afford it, wouldn't it be better to go 4" for all panels? Bryan?

And for bass trapping - don't forget that you have 8 more corners. Bass traps in wall/ceiling corners doesn't take any space you need.


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## bpape (Sep 14, 2006)

Keeping in mind that he was trying to do this on a budget for now, the 2" panels on the side walls and the front will do fine. 

Panels to cover the window would be good IF that's where they end up on the other side too. I was assuming that he wanted to maintain usability of the window easily.

Bryan


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## pfp (Feb 13, 2011)

This room has been and will be used for one purpose only - watching movies. The black out blinds on the window have rarely been open and once it's covered with a drape I strongly doubt that will be opened. It's perfectly fine if that window is a pain in the rear to use as it likely never will be.

If 4" panels on the walls will be much better than 2" I don't really have a problem with that - the cost difference isn't that much. Aesthetics might be the bigger issue there. 

I'm not so sure I can / will do much with the front wall. Once I do the bass traps on the sides the only space left will be on above or below the screen. I realize I probably should have done something to the entire wall first but that time has come and gone. I wasn't sure that it would make a dig difference since the screen is not acoustically transparent. Would it still be beneficial to add treatments above /below the screen?

I realize the other corners (wall / ceiling) could use bass traps too but to be perfectly honest that's further than I really want to go. Building the three bass traps that can sit on the floor will probably max out my carpentry skills. This is also a big reason why I don't think I'll put panels on the ceiling.


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## Crossblade (Jul 21, 2010)

If I were you, I would go for 4" panels (the budget for frames and clothing will be almost the same), symmetrically on both the left and right side (over the window). 

You can do bass traps for the floor/wall corners, but they will eat up space and aesthetics are not great. My ceiling/wall modules are like 12x12x25" each. You can something like this (or taller) and lay it on the floor instead of hanging from the ceiling.

For the three main traps - do the biggest you can. 

p.s. your room looks great and I am sure will be great once you finish with these improvements, which will give huge result!


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## bpape (Sep 14, 2006)

Do above and below the screen. 3 purposes here.

- Kill any reflections from the surrounds off the front wall.

- Boundary interaction control from the mains and center

- General decay time control without having to kill the surround field too much.


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## pfp (Feb 13, 2011)

Bryan,

I'm sold on the 4" for the rear wall as well as the need for some panels on the front wall. Would you recommend 4" for the front and sides or is 2" good enough?

Thank you
aul


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## bpape (Sep 14, 2006)

With broadband absorption in the front corners and on the rear wall, I think 2" panels will be just fine on the side walls. If you want to add some additional bass control, you could do false soffits up high around the perimeter of the room or even just front and back.


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## pfp (Feb 13, 2011)

One more question. At what height should I hang the 2' x 4' back and side panels?


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## bpape (Sep 14, 2006)

I would just start them 2' off the floor


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## Sirbrine (Sep 27, 2009)

I have a question about the broadband absorbers. Ignoring aesthetics, is there any benefit to installing them closer to the floor so that they are nearer to the intersection of the wall and floor?


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## kadijk (Jan 23, 2011)

One thing I read on an acoustics web site is that they hang the 2x4 2 inch thick side panels and bass traps away from the wall about 3.5-6 inches. This allows the sound waves to get behind the panel and in effect doubles the absorptive surface area


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## bpape (Sep 14, 2006)

Actually, if you're going to fudge, fudge toward the high side. The lower 1/2 of the room has lots of things to break up and absorb sound like people, furniture, carpet, the system, etc. Up high, there's nothing to help break up a lot of hard, flat, parallel surfaces.

The tri-corners are a good place for thicker panels which absorb bass which is why, in combination with sheer surface area, we recommend going floor to ceiling in the corners with bass control.

Bryan


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## TDO (Mar 8, 2011)

Great looking room, love the color scheme. As a quick side note, which program did you use to make your blueprints?


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