# Help on Home Theatre Treatments



## adol290 (Feb 3, 2011)

Hi, new to forum

It is time to treat my room. It is a basement home theater. After weeks of
reading I am ready to start . I would like to know if I am on the right track.
Comments suggestions would be very welcome. Note that I am unable to move
my equipment due to the dedicated electrical outlets.

The walls are Gyp-rock.

The area in red on the right and left side of the room is the first reflection area. It is about
4 ft wide and covers all 3 seats on the couch. I plan on placing 3 - 2'x4' x2" absorption panels
on each side. On the right side I have 2 sliding glass doors 2.5 ft wide, that slide into the wall.
I was thinking of creating some type of portable folding panel with 3 - 2'x4' x2" absorption panels.
On the left side the 3 panels can be mounted on the wall. The panels I was looking at are from
ATS acoustics. They are the only company I found that did not charge unbelievably high
shipping costs to Canada.

My ceiling is 7 ft 2" high. It is suspended, with 2ft x 2ft ceiling panels that i purchased from
home depot. Above the ceiling tile is open joists. I plan on putting 2 - 3" layers of Roxul
Safe and Sound in the joists(for a total of 6"). I plan on treating the area from the front of the couch
to the back of the room(blue striped area), and from the front of the couch forward to the front
of the speakers(in the blue striped area). This should help the bass correct?

The floor has an area rug about 6 inches longer than the couch, extending from the front of the couch
to the front L/R speakers. The floor itself is a wood laminate, which rests on a thin foam underlay,
over a concrete floor.

My next step would be the back wall. I do not have a clue of how many panels to use, or what thickness,
or where to place them.

The last would be the front wall. Again I have no idea.

Here is a picture of my room.


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## Ted White (May 4, 2009)

Hi and welcome to the Shack! is sound isolation a goal here?


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## adol290 (Feb 3, 2011)

My main goal is I am looking for sound absorption. My room has too much echo
in the mid/high frequencies. Especially with the glass sliding doors. 

I also would like to address bass absorption. 

I had read an article from Ethan Winer about putting insulation in the ceiling that
would help with bass absorption. A side effect is it will also provide some isolation.

http://www.ethanwiner.com/acoustics.html#fiberglass traps

Select - Fiberglass bass traps - on the right side of the page and go down a bit


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## Prof. (Oct 20, 2006)

Without seeing a photo of the room, the only suggestion that I can make is to use the standard acoustic treatments that are used in most theatre environments..

Bass traps floor to ceiling in the front and rear corners and wall panels at the first and second reflection points..
You will also need panels on the rear wall if it's a blank wall..

The side wall panels need to be 2" thick semi rigid fibreglass and the rears about 4" thick..All the panels can be 2'x4'.

The bass traps need to be either 6" thick flat panels or super chunks (triangular sections) stacked on top of each to the ceiling..

I hope that helps..


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## adol290 (Feb 3, 2011)

Prof.

Here are pictures of my room. Taken on a cheap cell.


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## Prof. (Oct 20, 2006)

Thanks for the pics..

The front wall will be fine for bass traps..providing you remove the pot plant from the right corner..

The LHS wall will most probably be OK for first and second reflection point panels, although the second point might be close to your surround speaker..You'll have to check where this point lies..
The side wall panels will need to be mounted about midway up the walls..

The RHS wall might be a problem with those double doors and recess..The first reflection point might be on the right side door or just passed it..You might have to fix a panel over that right side door!..

On the back wall, one large or two smaller panels immediately behind the sofa will help tremendously..


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## adol290 (Feb 3, 2011)

Thanks for the info.

In my first post I have a PDF attachment that shows the area of the first reflection points. 

Your correct, that on the right hand side it lies on the glass door. 

So how do I find the second reflection points?


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## bpape (Sep 14, 2006)

Don't worry about 2nd reflections. If you get the early ones on the side walls, you'll be fine.

On the rear wall, think 3 panels at 2'x4'x6" spaced about 4-6" apart centered behind the seating area.

For the ceiling, you'll want to do over your head and probably 2' out all around the perimeter of the room at a minimum. Doing the entire ceiling will only help and will also help reduce sound transmission in both directions.

For the ceiling, you could also use drop in diffusers in the grid like our Grid Fusors. The tiles you have look pretty 'hard' in terms of mid/high frequency reflection. Some diffusion would be a nice addition - though not sure it's doable given the very low ceiling height already.

Bryan


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## adol290 (Feb 3, 2011)

bpape

For the ceiling

If i put 2 - 3" layers of Roxul Safe and Sound in the joists above the ceiling tiles, and did the whole ceiling, how many 2'x2' drop in diffusers would you recommend. And where would i put them?

For first reflections 

The first reflections span about 4 ft across each side wall. This area covers all 3 seats on the couch. Would I put 2 - 2' x 4' x 3" panels together no space in-between, or use 3 panels together to allow an extra foot on each side.


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## bpape (Sep 14, 2006)

No need for anything that dense in the ceiling. Simply fluffy insulation, likely at least R-30 would be fine.

Whether you do 2 or 3 on each side wall will depend on the overall decay time in the room and what's needed. Might be better to just do 2 and then use the additional (and thicker) absorption elsewhere to get a better ovreall decay time curve without overdoing the HF absorption.

For the diffusers, I was thinking some in the rear behind the seating to scatter some of the rear energy and minimze any direct reflections floor to ceiling in higher frequencies. Probably 4 would be appropriate based on your layout. The other place would be at the ceiling reflection points between you and the speakers. Again, 4 would likely be required there.


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## DanTheMan (Oct 12, 2009)

Bryan, any height recommendation for the new ceiling diffusors?

Thanks,

Dan


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## bpape (Sep 14, 2006)

It would depend where they're going. For the rear wall, they can start at about 2' off the floor and go all the way up.

Reflection points on the side wall - standard 2'-6' high.

Up high around the perimeter of the space with the sound being scattered side to side (ribs vertical) will help quite a bit with general slap echo where there is no furniture or people to break things up but doing so without losing any energy in the surround field. In fact, it will actually help the surround field.

Bryan


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## DanTheMan (Oct 12, 2009)

Oops, I was talking about the ones for the drop ceiling--does the ceiling need to be at least 8ft or 10ft for them to work properly? Or will they be beneficial no matter what? Diffusion is still a great mystery to me even though I get how it works. What's mostly available to read about is absorption. A diffuse sound field sure seems like a good idea for envelopment's sake. I'm betting it sounds more like absorption than most imagine at this point though. That's what I hear when I visualize it.:scratch:

Dan


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## bpape (Sep 14, 2006)

In a situation like a ceiling reflection you don't need the tall ceilings. You already will have plenty of distance to allow the diffusion to be effective.

Diffusion does not, in theory, remove any energy from the room. It simply scatters sound evenly in both space and time - whereas absorption does not do any redirection or time alterations. Its goal IS to remove energy from the room. 

One other thing - if you think absorbers need to be thick to function lower, diffusion is even more demanding. Most 6" deep diffusers will function optimally down to around 550Hz (depending on their design) and will do some scattering down into the mid 300's.


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## DanTheMan (Oct 12, 2009)

Thank you Thank you Bryan! You actually just cleared up questions I didn't ask. Now to build my cloud(s).

Dan


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## Tufelhundin (Jan 25, 2010)

This thread is very helpful to me....not trying to Hi-jack just asking for more info concerning the OP's room that may help him and others as well.

curious here, the OP has low ceilings, mine (92") and I see mention of bass traps in corners from floor to ceiling....is there an optimum plan here other than having something special ordered due to a 4' length of traps?? Maybe Tri standing on floor with a 244 placed in front of the Tri on a stand tall enough for it to reach the ceiling or vise versus? 

I see bpape said 3 6" traps across the back wall....what about the front?


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## bpape (Sep 14, 2006)

You could certainly do something like the 1 in the corner and one on a stand but it's going to look kind of funky as well as ending up being more expensive than just doing a custom sized one.


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