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Unopened bundles of R-13?
Old 11th April 2013
  #1
Gear Addict
 

Unopened bundles of R-13?

I have several unopened bags of R-13 rolled up insulation available.
One is actually jumbo size : 48" high and weighs in at 30 pounds, which works out to almost 3lb/cuft. The others are smaller.

Do they server any purpose as bass trapping in their tightly rolled up state?

For example, I have some corner panels and another large space ( semi-circular rear wall) that may need treatment. Should I use them as is?
Or burst them and let them expand into some kind of mounting frame?
(once the cat's out of the bag, its not easy to re-roll as tightly)
Old 12th April 2013
  #2
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Open them up and let them expand. They don't work nearly as well while bundled.
Old 12th April 2013
  #3
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Glenn Kuras's Avatar
Agreed with the above but for fun you should stick them in the corners unopened. You should notice a pretty big difference in the low end.
Old 12th April 2013
  #4
Gear Addict
 

Quote:
Originally Posted by Glenn Kuras View Post
Agreed with the above but for fun you should stick them in the corners unopened. You should notice a pretty big difference in the low end.
OK thanks - would there be any issue about having the opened , expanded fluffy sitting loosely in large contractor garbage bags? (obviously this is a lot neater, easier to deal with etc ...). Also I believe most of it is paper faced - I assume thats not much of a factor, is it ?

FYI
At one point I did have the unopened bags in the front corners, behind stradled rockwool bass traps (4 feet wide). But they weren't filling the space more than halfway. Any additional effect was minimal, so I didn't put them back in.

It was a few years ago that I read they may be useful in the unopened state. The idea being its about the same density as OC703. But maybe the consensus since then has changed.

Now I figure if I opened them I may have enough to fill both the front corners AND / OR most of the back wall area ....

The back wall is dominated by a semi-oval bay window area.
Its not symmetrical but its about 8 feet wide and has a maximum depth of about 4 feet. Being in the basement, it is mostly cement (4 feet high + 2.5 ft for the actual basement windows).

I've had the window shelves jammed with these unopened bags plus a few on the floor. Now that I've been measuring things I see it helped a bit, maybe 2-3 db on certain problem nulls, but thats not a lot considering the fairly massive amounts that are there.

I'm also trying some more 4" OC703 panel traps to block the area. Basically a false wall 8 feet wide x 6 feet high. making a pushed in "V" shape into the oval measures better than straight across (and wastes less real estate).
Its been getting better, but there's still a null point eluding me....

the hunt continues!
Old 12th April 2013
  #5
Gear Guru
 
Glenn Kuras's Avatar
Quote:
OK thanks - would there be any issue about having the opened , expanded fluffy sitting loosely in large contractor garbage bags? (obviously this is a lot neater, easier to deal with etc ...). Also I believe most of it is paper faced - I assume thats not much of a factor, is it ?
I have never tested it but can't see why it would not work.
Old 12th April 2013
  #6
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avare's Avatar
 

Try it! The time to move them is less than waiting for responses here.

Andre
Old 12th April 2013
  #7
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Someone already did test it, but I forgot what thread it was. The result was that opening the bag worked, and not opening didn't work.
Old 13th April 2013
  #8
Gear Addict
 

Quote:
Originally Posted by OpusOfTrolls View Post
Someone already did test it, but I forgot what thread it was. The result was that opening the bag worked, and not opening didn't work.
thanks! I may do that in a day or two.

Last night I measured the biggest null around 94, then walking around the room with the meter while running the sine generator I noticed something very interesting. And not totally unexpected: At just about every point in the room there was buildup at the floor-wall boundary.

halfway up was usually at least 3db less and the ceiling wasn't too bad, somewhere in between

The floor is cement and the only untreated surface...
Old 13th April 2013
  #9
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Quote:
Originally Posted by avare View Post
Try it! The time to move them is less than waiting for responses here.

Andre
i don't mind taking time to experiment, I've already removed / replaced them just to see the effect.
(Actually there are 3 of the big, 30 lb bundles)
But I'm contemplating more than just moving them. Once they're opened , there's no "undo" button.
Old 13th April 2013
  #10
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Quote:
Originally Posted by jeff_free69 View Post
i don't mind taking time to experiment, I've already removed / replaced them just to see the effect.
(Actually there are 3 of the big, 30 lb bundles)
But I'm contemplating more than just moving them. Once they're opened , there's no "undo" button.
If they have the desired result bundled,then you have succeeded!

Successfully,
Andre
Old 1st October 2019
  #11
Gear Head
 

Quote:
Originally Posted by Glenn Kuras View Post
Agreed with the above but for fun you should stick them in the corners unopened. You should notice a pretty big difference in the low end.
so it's always better to open a package and then set things up.. as opposed to simply stacking unopened packages?
Old 2nd October 2019
  #12
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avare's Avatar
 

Quote:
Originally Posted by mikeklein View Post
so it's always better to open a package and then set things up.. as opposed to simply stacking unopened packages?
Absolutes scare me. What are you trying go acheive?
Old 2nd October 2019
  #13
Gear Head
 

Quote:
Originally Posted by avare View Post
Absolutes scare me. What are you trying go acheive?
well.. thanks, i was hoping to stack up unopened packages of insulation for bass trapping.. to avoid inhaling harmful stuff, and making frames.. and getting fabric..

but it seems people are saying unopened packages of insulation won't get the job done..
1) some issue about compression
2) it's not cost effective
3) actually becomes reflective due to too much thickness i think was said?

anyway..

if i do open the packages up..

i'd plan to make panels straddling the corners with an air gap..
not mounted on walls, and not super-chunked..
with this being the case..

can i just use any insulation..
as long as at 8'' thick.. it's <3pcf,
and at 12'' thick.. <2.5pcf?

thanks
Old 2nd October 2019
  #14
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avare's Avatar
 

Quote:
Originally Posted by mikeklein View Post
well.. thanks, i was hoping to stack up unopened packages of insulation for bass trapping.. to avoid inhaling harmful stuff, and making frames.. and getting fabric..

but it seems people are saying unopened packages of insulation won't get the job done..
1) some issue about compression
2) it's not cost effective
3) actually becomes reflective due to too much thickness i think was said?

anyway..

if i do open the packages up..

i'd plan to make panels straddling the corners with an air gap..
not mounted on walls, and not super-chunked..
with this being the case..

can i just use any insulation..
as long as at 8'' thick.. it's <3pcf,
and at 12'' thick.. <2.5pcf?

thanks
Sure if you want to spend lots of money.
Old 2nd October 2019
  #15
Gear Head
 

Quote:
Originally Posted by avare View Post
Sure if you want to spend lots of money.
so what should i get to spend the least amount of money
Old 2nd October 2019
  #16
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avare's Avatar
 

Quote:
Originally Posted by mikeklein View Post
so what should i get to spend the least amount of money
The.cheapest insulation.
Old 2nd October 2019
  #17
Gear Head
 

Quote:
Originally Posted by avare View Post
The.cheapest insulation.
these are the cheapest bags i could find
https://www.lowes.com/pd/Johns-Manvi...8-in-L/3012132

24 x 48 x 12 = 13,824 .... divided by 1782 for feet = 7.8
package weight = 32.98 pounds .. divided by 7.8 = 4.2 pcf

4.2 pcf is too high (i've read) for 12'' thickness..

if we divide 32.98 by 8 (to get the weight of each batt)..
we get 4.1

if we do 4.1 divided by 7.8
(in an attempt to get the pcf per single batt, if this is even logical)
we get .53 .. which seems way too not-dense per 12'' batt..

so.. going with the cheapest insulation..
it seems (unless i'm mistaken)
won't work here

thoughts? thanks
Old 2nd October 2019
  #18
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avare's Avatar
 

Quote:
Originally Posted by mikeklein View Post
these are the cheapest bags i could find
https://www.lowes.com/pd/Johns-Manvi...8-in-L/3012132

24 x 48 x 12 = 13,824 .... divided by 1782 for feet = 7.8
package weight = 32.98 pounds .. divided by 7.8 = 4.2 pcf

4.2 pcf is too high (i've read) for 12'' thickness..

if we divide 32.98 by 8 (to get the weight of each batt)..
we get 4.1

if we do 4.1 divided by 7.8
(in an attempt to get the pcf per single batt, if this is even logical)
we get .53 .. which seems way too not-dense per 12'' batt..

so.. going with the cheapest insulation..
it seems (unless i'm mistaken)
won't work here

thoughts? thanks
Wow I have never of denser being cheaper. You want under 2 lb/ft3 fiberglass or 3 lb/ft3 mineral wool.
Old 2nd October 2019
  #19
Gear Head
 

Quote:
Originally Posted by avare View Post
Wow I have never of denser being cheaper. You want under 2 lb/ft3 fiberglass or 3 lb/ft3 mineral wool.
ok thank u very much, i'll reply again if any questions..
let me know if i can do anything for u..
btw.. i called the store to make sure that price was right,
because it confused me too,
but the guy said the same price as on the internet page..
so.. unless he was mistaken, yeah
Old 2nd October 2019
  #20
Gear Head
 

Quote:
Originally Posted by avare View Post
Wow I have never of denser being cheaper. You want under 2 lb/ft3 fiberglass or 3 lb/ft3 mineral wool.
actually i do have one question, just to be sure..

when i'm taking the ''package weight'' of these bags..
and dividing that by x (when x = l x w x h / 1782)
that gives me the pcf of the entire package right?

but, my goal is to get the pcf of a single batt right?

so then i'd have to divide that number by
the amount of pieces in the package right?
to get the pcf per each piece?

thanks

edit: also, maybe i should mention this..

i plan to remove the batts from the bag,
and put them in garbage bags, no frames..
and hope the garbage bags stack up straddling the corners..
might wrap the garbage bags in fabric first before stacking

thanks
Old 2nd October 2019
  #21
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avare's Avatar
 

Yes.
Old 4th October 2019
  #22
Here for the gear
 

Quote:
Originally Posted by mikeklein View Post
actually i do have one question, just to be sure..

when i'm taking the ''package weight'' of these bags..
and dividing that by x (when x = l x w x h / 1782)
that gives me the pcf of the entire package right?

but, my goal is to get the pcf of a single batt right?

so then i'd have to divide that number by
the amount of pieces in the package right?
to get the pcf per each piece?

thanks

edit: also, maybe i should mention this..

i plan to remove the batts from the bag,
and put them in garbage bags, no frames..
and hope the garbage bags stack up straddling the corners..
might wrap the garbage bags in fabric first before stacking

thanks
Just some of my recent (er .. still in process) experience with fluffy mineral wool if it will help somehow.
I use Knauf Acoustical Smooth Board with ECOSE® Technology mineral wool 2" thick plates for 12" deep bass traps.
Proper GFR and acoustical effect can be expected only if plates are exposed to air without any compressing package (because in industrial quantities they arrive compressed somewhere around 6-8 times - when you cut wrapping, they pop out like thrown by spring) and then packed in some film.
Not sure if garbage bags are good for something reusable - i use 0,2 mm polyethylene film roll. You shall calculate if you save something with garbage bags instead big roll of film and pack of tape.
I try to make some kind of "matress" and if they are stacked side-to-side, they completely do not compress themselves and lower layers (very light!). So, i can be sure that such solution is fluffy enough to work well in deep construction and stable enough to keep its form if supported with some kind of frames/beams.
If you want to use some kind of rolls which cannot hold any shape just standing straight by themselves, you'd better consider some frame. I preferred rectangular plates, because they don't require so much effort to make bunch of these more or less stable.

Hope it will save your time and money.
Old 5th October 2019
  #23
Gear Head
 

Quote:
Originally Posted by avare View Post
Yes.
thank u, blessings..
email me if u need anything
[email protected]
appreciate ur help
Old 5th October 2019
  #24
Gear Head
 

Quote:
Originally Posted by fedorM View Post
Just some of my recent (er .. still in process) experience with fluffy mineral wool if it will help somehow.
thank u very much for your reply..
today i got 1 package of r38 from lowes by johns mansville,
for 20 bucks including tax..
each batt is 12 inches thick,
and it comes with 8 batts in a package..

i let them out of the package..
then put each one in a double packed big plastic garbage bag..
and i have them in my vocal booth just in garbage bags..

and it seems like the boomy-ness and deep resonance
in my vocal booth has gone away slightly..
by slightly.. i mean.. it is noticeable, the difference (which is good)..

the plastic provides some higher frequency reflections i guess..
which is actually good for my very dampened space..

as a last point here..
i actually plan to make a diffuser, but get this..
i plan to buy a jenga set..
and some wood toy blocks (you know with letters on them)..
and i'll just arrange the diffuser that way,
gluing the pieces onto the jenga or blocks cardboard packaging..
(that's my plan at least)
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