# Motivated, yet Lazy



## bbieger (Sep 15, 2009)

OK, so I am nearing the point when I need to start buying some acoustic treatments to my home theater. Been doing waaaay too much reading and what not and in the end, just decided that posting up here and having someone offer up suggestions would be the best bet. For those not familiar with my monkeyboy HT thread, here is the skinny on my room...


10.6' x 26' x 7 foot tall. 5/8 drywall in front of r13 on all walls. Ceiling is double 5/8 hanging from hat channel and whisper clips. Going to have a fairly plush carpet and padding installed over the wood subfloor.

My initial thought was just to cover the front wall in 2" OC 703, angle a sheet or two to cover the corners and call it good. Perhaps though I am going to need to build some panels for the wall as well? Or even better still, maybe I should wait until everything is installed, buy the gear necessary to see what frequencies in the room are doing and then make adjustments. 


While I'm not overly concerned that I don't have recording studio perfection in my HT I do want my bass to sound tight and get rid of any echos.

Suggestions>?


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## bpape (Sep 14, 2006)

2" on the front wall is fine. You'll want floor to ceiling and something thick in the corners for broadband control.

In a room that length, and assuming 2 rows, you'll need at least 3 2'x4' panels on the side walls for reflections - more to get the overall decay time in the room right.

Bryan


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## bbieger (Sep 15, 2009)

only one row of seating.. well one that counts anyways . For the front corners do you advise doing the triangle 703 stack? do those need to go all the way from floor to ceiling? that is allot of 703..

Thanks Bryan!!


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## bpape (Sep 14, 2006)

Yes. Floor to ceiling and solid is best. To do 2 corners, 8' tall with 17x17x24" triangles takes 12 2'x4'x2" pieces of OC703

Bryan


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## Ted White (May 4, 2009)

Hey monkeyboy. Nice to hear from you.


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## bbieger (Sep 15, 2009)

Is there a big advantage to having a little space behind the 703 sheets? Like say 2"? Thinking about gluing the panels directly to the wall but it would be easy to throw a small frame together and screw them to that. So I guess it would be an 1 1/2" of dead air space behind them.

Still waiting to hear back from the sheep wool guy for my corner traps.


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## bpape (Sep 14, 2006)

Absolutely depending on where you're using them and what's required. The additional gap, up to the thickness of the absorption, will extend the bottom end effectiveness.

Bryan


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## bbieger (Sep 15, 2009)

great! I am using them on the front wall so I'll glue a grid of 2 x 2's on the wall and screw them to that


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## bbieger (Sep 15, 2009)

last question i swear!!

my local source has 8lb rock wool board in 11/2 and 2" thickness. Is 8lb/sq ft too dense? Based on the density should I just get the 1 1/2"? I will be using it for the front wall and also to build some panels. 

Thanks!!
Brian


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## bpape (Sep 14, 2006)

Thickness is more important. If you can get it in a lower density and the 2", it will work as well or better and be cheaper. Even 2.5lb would work fine.

Bryan


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## bbieger (Sep 15, 2009)

Found another source. I went to the warehouse and the were drinking micro brews in the office lol. They only had a minimal amount of 6lb and they didn't want to break up the packs of 4lb. Blah blah blah; one shared beer later... I walk out with 16 sheets of 6lb and 8 sheets of 4lb for $82.90!!!

Yipee!! SWEET deal and a free beer.
_Posted via Mobile Device_


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## Lonely Raven (Aug 27, 2008)

bbieger said:


> Found another source. I went to the warehouse and the were drinking micro brews in the office lol. They only had a minimal amount of 6lb and they didn't want to break up the packs of 4lb. Blah blah blah; one shared beer later... I walk out with 16 sheets of 6lb and 8 sheets of 4lb for $82.90!!!
> 
> Yipee!! SWEET deal and a free beer.
> _Posted via Mobile Device_


That's a hell of a deal. I think I paid $75 of 9 sheets of 3lb.


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## bbieger (Sep 15, 2009)

Picture of front wall and and corner bass traps. You can see in the bottom of the photo the 2x2's I used to hold the panels off the wall. Pretty simple. Cheap black burlap will cover the entire treatment once it arrives.


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## Lonely Raven (Aug 27, 2008)

Looks like a nice front end setup!


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## ths61 (Jan 14, 2010)

bbieger said:


> Picture of front wall and and corner bass traps. You can see in the bottom of the photo the 2x2's I used to hold the panels off the wall. Pretty simple. Cheap black burlap will cover the entire treatment once it arrives.


Keep us posted on how it sounds and measures. 

I am considering lining the front wall in addition to the existing floor-2-ceiling corner traps. I just put 4 cases of OC705 on order this morning.

Cheers,
Tim


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## bbieger (Sep 15, 2009)

I'll take some measurements..going to be a few weeks for sure. Going to take a week off from the portland rain and head to florida. I just bought an external sound card and SPL meter but I've never done a room sweep.

One thing I didn't notice a change in is the room is still echos allot. Probably cause no carpet and furniture. Doing the front wall only took about an hour. Box of 3" screws and washers...zip zip zip. 

I can't emphasize how itchy the rock wool is. Make sure to baby powder up before working with the 703 and wear a mask. Insulation fibers in your lungs will still be there when they put you in the ground.


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## ths61 (Jan 14, 2010)

What are the dimensions of your corner wedges (17"x17"x24" - 8/panel) or (24"x24"x34" - 4/panel) or something else?

BTW, it rains in Florida too !!! Stay Dry !!!


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## bbieger (Sep 15, 2009)

my corners are 17 17 24. I have an inch of free space behind them as well. It will NOT rain in florida while I am there


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## ufokillerz (Dec 4, 2009)

bbieger said:


> my corners are 17 17 24. I have an inch of free space behind them as well. It will NOT rain in florida while I am there


hi i'm new to this, i am looking to do the same can you point me out to how to cut 17 17 24 properly, my imagination is lacking and i can't picture it.


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## ths61 (Jan 14, 2010)

ufokillerz said:


> hi i'm new to this, i am looking to do the same can you point me out to how to cut 17 17 24 properly, my imagination is lacking and i can't picture it.


You can either cut 4 or 8 triangle pieces out of each 2'x4' panel. You start out by cutting each 2'x4' panel into 2- 2'x'2' panels. Simply cut it half, bisecting the long 4' side ([ | ]).

Once you have a 2'x2' square piece([ ]), you can either cut it diagonally once ([/]) or twice ([X]). 

A single diagonal cut ([/]) would yield 2 right triangle pieces from the square, each with a 34" hypotenuse.

A double diagonal cut ([X]), would yield 4 right triangle pieces from the square, each with a 24" hypotenuse.

You then stack the triangle pieces with the hypotenuse facing the room and the 90 degree corner facing the room's wall-2-wall corners.

8 pieces per panel ([X|X]) is more cost effective, while 4 pieces per panel ([/|/]) gives each corner @ 50% more corner surface area for more absorption.

HTH,
Tim


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## bbieger (Sep 15, 2009)

and again to reiterate bpape's very helpful post, it takes 12 sheets of 2" to fill 2 8' high corners. 

oh yeah, sunny and 75 today in FLA. Spent 2 hours kiteboarding and did not lift one finger on my HT build  (although I have been wasting hours deciding on a DIY sub build) hee hee. Table Tuba here I come !!


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