How thick of OC 703 for corners to impact bass?

CJ Paul · « **on:** 2 Feb 2006, 06:30 pm »

OK, I have a local source for Owens Corning 703 rigid fiberglass. How thick should I use for corner panels? I'm thinking of doing (2) 2 x 4 panels in the corner plus (2) triangles in the 3-way corner where the corner of the walls meets the ceiling. What thickness should this be to act as bass traps. Also, if money is an issue, would you treat for bass first or reflection points for high/mids first?

Also is $9 a 2x4 sheet of 1" thick 703 a good price?

bpape · « **Reply #1 on:** 2 Feb 2006, 06:59 pm »

$9 for 1" is kind of high for a local price. You should be able to get 2" for that.

With 703's lower density (3lb/cu ft), 4" min - 6" recommended for good solid bass absorbtion down relatively low - straddling the corner.

CJ Paul · « **Reply #2 on:** 2 Feb 2006, 07:17 pm »

OK, I was quoted 1.14 per square foot. Each sheet is 8 square feet. I think I found the only local distributer of OC that sells to the public. I did find this place a while back though (http://www.insulationworld.com/prodList.asp?idcategory=36&curPage=4&sortField=price) and their insulation is 8 pounds per cubic foot, so I assume I could get by with less thickness?

Is there a different model number of OC that is denser?

Carlman · « **Reply #3 on:** 2 Feb 2006, 08:06 pm »

OC705 is a 5 lb. density.
Using OC703, 2 2" boards sandwiched to make 4" is the standard most people use for bass traps. I've never heard or seen 6" used in all the case studies on the web.

I paid $1.20 per sf for 2" OC703 w/ a foil facing.

Glenn K · « **Reply #4 on:** 2 Feb 2006, 11:51 pm »

Quote from: Carlman

OC705 is a 5 lb. density.
Using OC703, 2 2" boards sandwiched to make 4" is the standard most people use for bass traps. I've never heard or seen 6" used in all the case studies on the web.

I paid $1.20 per sf for 2" OC703 w/ a foil facing.

As I don't want this to come off as advertising, really I do not, but I think I can shead a little light on the 4" vs 6"
Our last lab run for the 244 (4"), "J" testing, straddled in corner

Absorption Coefficient
50hz .58
63hz .78
80hz 2.02
100hz 1.85
125hz 1.64

Now a new trap that is 6"

50hz .63
63hz 1.27
80hz 3.00
100hz2.34
125 hz 2.00

I think it is pretty clear that if you want to smack the low end then use 6".. BTW, the number for 6" beat not only on the low end but also the high end, way more then what we thought it would..

Glenn

tdangelo · « **Reply #5 on:** 3 Feb 2006, 12:16 am »

Glenn, are you going to make your panels using the 6" material?

Thanks

Tony D.

richlo · « **Reply #6 on:** 3 Feb 2006, 05:25 am »

Quote from: tdangelo

Glenn, are you going to make your panels using the 6" material?

Thanks

Tony D.

Actually I bought 2 of the 2x4 7.5"thick

panels from him, that I took receipt of yesterday evening...they are the 247 model not posted on the site..

MUY ALEGRE!!!

bubba966 · « **Reply #7 on:** 3 Feb 2006, 05:30 am »

Quote from: Carlman

OC705 is a 5 lb. density.
Using OC703, 2 2" boards sandwiched to make 4" is the standard most people use for bass traps. I've never heard or seen 6" used in all the case studies on the web.

I paid $1.20 per sf for 2" OC703 w/ a foil facing.

Carl, I've used 6" of 703 as floor to ceiling bass traps before. Worked rather nicely I must say...

Glenn K · « **Reply #8 on:** 3 Feb 2006, 12:45 pm »

Quote from: tdangelo

Glenn, are you going to make your panels using the 6" material?

Thanks

Tony D.

Yes, but not to get off the subject, please just email me for info...

Carlman · « **Reply #9 on:** 3 Feb 2006, 01:40 pm »

OK so I do a few months of research and track down the OC703, buy it, and then find out I don't have enough.
......Gee thanks...

Thanks for the research, Glenn...

Sharing research results is what this forum is all about... and definitely not considered advertising.

CJ Paul · « **Reply #10 on:** 3 Feb 2006, 02:21 pm »

There is a photostiched picture of my room. As you can see, the left corner is by the stairs that come down. Would you still threat the left and right corners identically as if the room were semetrical?

CJ Paul · « **Reply #11 on:** 3 Feb 2006, 05:45 pm »

I just found a local source for some rock wool. Its 8 pound per cubic foot and its $30 for six 2'x4'x2" sheets. I think I'm going to pick some up. Does anyone have a response to my picture?

Red Dragon Audio · « **Reply #12 on:** 3 Feb 2006, 07:53 pm »

Quote from: CJ Paul

I just found a local source for some rock wool. Its 8 pound per cubic foot and its $30 for six 2'x4'x2" sheets. I think I'm going to pick some up. Does anyone have a response to my picture?

I'd say pick up a 2-3 boxes (I presume that each box contains 6 sheets).

That's a fantastic bargain for the return you'll certainly get on your money.

This will give you more panels to experiment with in your room.

By the way I'm jealous of what looks to be a pair of stereo mounted dual IB subs...

CJ Paul · « **Reply #13 on:** 3 Feb 2006, 08:08 pm »

Quote

By the way I'm jealous of what looks to be a pair of stereo mounted dual IB subs...

That's what it is. My room is 24'x38' so I need a lot of sub...

Glenn K · « **Reply #14 on:** 3 Feb 2006, 08:55 pm »

Quote from: Carlman

OK so I do a few months of research and track down the OC703, buy it, and then find out I don't have enough.
......Gee thanks...

Thanks for the research, Glenn... Sharing research results is what this forum is all about... and definitely not considered advertising.

Thanks, but don't let me tell you 4" would not work also.. If that is what you have then I would use it.. I don't want to start a new 6" standard YET!!!!! ha ha ah

Glenn

ryanallen · « **Reply #15 on:** 3 Feb 2006, 11:08 pm »

Quote from: CJ Paul

There is a photostiched picture of my room. As you can see, the left corner is by the stairs that come down. Would you still threat the left and right corners identically as if the room were semetrical?

Looks like you can still mount a trap in that corner by the stairs. But to answer your question, a trap can be mounted in any corner not just wall/wall corners. Try wall/ceiling or wall/floor combos as well.

Inscrutable · « **Reply #16 on:** 3 Feb 2006, 11:38 pm »

Not to hijack your thread CJ, but what the heck - I know you thrive on abuse

I found this thread on resonance/absorption by different wall systems interesting, and since we're talking thicknesses and densities and measurements ... oh my! ... yeah its a bit of a stretch.
http://www.avsforum.com/avs-vb/showthread.php?t=638531

richlo · « **Reply #17 on:** 4 Feb 2006, 02:35 am »

Quote from: CJ Paul

Quote
By the way I'm jealous of what looks to be a pair of stereo mounted dual IB subs...
That's what it is. My room is 24'x38' so I need a lot of sub...

YEAH - We all know you from Hometheatertalk...there is a CULT IB going on over there

I WANTS ME SOME IB>>IWANTS ME SOME IB

Carlman · « **Reply #18 on:** 4 Feb 2006, 02:12 pm »

Quote from: Glenn K

Quote from: Carlman
OK so I do a few months of research and track down the OC703, buy it, and then find out I don't have enough.
......Gee thanks...

Thanks for the research, Glenn... Sharing research results is what this forum is all about... and definitely not considered advertising.

Thanks, but don't let me tell you 4" would not work also.. If that is what you have then I would use it.. I don't want to start a new 6" standard YET!!!!! ha ha ah

Glenn

Oh, but you have! I went and bought more OC yesterday... So now I have enough to do 6" panels from ceiling to floor in the corners... and enough for the wall behind my head, and primary reflection points.

I still can't get over how stinky they are... I didn't see that tidbit anywhere in my reading either...

So, if I add the extra $55 to my project, I'm around $300 for a fully treated room including all materials. Not terrible.

-C

richlo · « **Reply #19 on:** 4 Feb 2006, 05:36 pm »

Quote from: Carlman

Oh, but you have! I went and bought more OC yesterday... So now I have enough to do 6" panels from ceiling to floor in the corners... and enough for the wall behind my head, and primary reflection points.

I still can't get over how stinky they are... I didn't see that tidbit anywhere in my reading either...

So, if I add the extra $55 to my project, I'm around $300 for a fully treated room including all materials. Not terrible.

-C

Let us know how it impacts your room...how does it sound to you..