Armstrong 420 rigid fiberglass

[wilkinswp]

Has anyone tried Armstrong 420 rigid fiberglass for treating rooms? I saw some at Lowe's today. The NRC is 0.55. The pieces are 5/8 inches in depth. Anyone used these as an alternative to some of the other suggested fiberglass solutions?

Thanks in advance.

[Ethan Winer]

Wilkins,

A couple of comments:

> I saw some at Lowe's today <

Yes, that stuff will work okay. You need to peel off all the plastic layers, and place them adjacent to be at least 2 inches thick for mid/high frequency control, or 4 inches thick for bass trapping.

> The NRC is 0.55 <

NRC is a useless spec for audio work because it's an average of the absorption at speech frequencies only. What really matters is how well the material absorbs in each band over the entire audible range. But assuming the stuff is real rigid fiberglass, it will work.

--Ethan

[wilkinswp]

Ethan,

Thank you for the input. I was hoping to hear from you.

Palmer Wilkins

[adigga]

I have also come across this insulation in Home Depot and considered using it for building Ethans membrane bass traps. Has anyone been able to find the specs on these, such as density. I've tried but have been unsuccessful. Don't want to use them if they are not equivalent to Owens Corning 703.

andrew

[Acoustic Cloud]

http://www.atsacoustics.com/cat--Raw...ials--102.html

check this out....great prices, and you dont even have to fight the "Disneyland" that is Lowes. I got all my acoustic cloud...he he material I built from them. Burlap prices are good too, and they have different colors. great source for 703, since its not available in the stores.

[adigga]

Acoustic cloud,

Thanks for the site. I was hoping to save on the shipping and be able to pick up the items today. I still haven't been able to find specs on these panels.

Andrew

[studio825]

oc 703 is not mineral wool.

[studio825]

min wool is the better of the two for absorbtion

[adigga]

Question for Ethan,

I was wondering if you had seen any specs on the Armstrong 420 rigid fiberglass panels. I am hoping to build the membrane traps and design my room according to your specs but wanted to ensure that the armstrong panels are appropriate before sealing the panels.

Thanks,

Andrew

[Ethan Winer]

Andrew,

> I was wondering if you had seen any specs on the Armstrong 420 rigid fiberglass panels. <

I don't have any data but I assume the manufacturer does! Did you ask them?

Regardless, mineral wool works well, and you should look for a density of around 4 to 8 pounds per cubic foot.

--Ethan

[Glenn Kuras]

Originally Posted by adigga

Acoustic cloud,

Thanks for the site. I was hoping to save on the shipping and be able to pick up the items today. I still haven't been able to find specs on these panels.

Andrew

Check to see if you have a SPI in your area. They might have it also.

Glenn

[adigga]

I wrote Armstrong questioning the density of the Random Fissured fiberglass ceiling panels found at Home Depot and received the following response:

"Good Morning,
To figure pounds/cubic feet :
Pounds/square feet x 12 divided by the thickness of the panel = Pounds/cubic feet.
Random Fissured 420 is .20 lbs/square foot.
.20x12=2.4
2.4/.625=3.84"

This seems to be in line with Owens Corning 703 density (slightly higher). According to Ethan Winers membrane bass trap plans two panels should be equivalent to one 1" thick 703. Any comments?

Andrew

[partnering]

I also saw a box of these at lowes. looks to be 2x4 and has like 10-12panels at 5/8inch thickness with a white plastic layer. the package thickness looks to be about 12inches deep. these are obiously ceiling tiles.
my question is the package is wrapped in plastic and cardboard around the edge but the sides are open. can i just stick this whole thing catacorner and use it as a bass trap like it is with plastic wrapping and cardboard et. all?

not even worried about taking the plastic white layer off hoping it works on bass frequencies also. mabe cut around the plastic to expose the fiberglass side to the room?
just a thought. thanks

[Ethan Winer]

Originally Posted by partnering

can i just stick this whole thing catacorner and use it as a bass trap like it is with plastic wrapping and cardboard et. all?

Yes.

[partnering]

okay thanks

i guess this is similar to stacking bags of fluffy pink stuff in your corners?

also what happens if i try to make panels by using 4 of these 5/8 sheets together but don't take the white ceiling layer off? like just have them stacked but put the fiberglass side towards the room. will the (4) plastic layers affect its performance?
at first reflection points and as high/mid absorbers.
I don't see an easy way to peel that layer off.

[Ethan Winer]

Originally Posted by partnering

what happens if i try to make panels by using 4 of these 5/8 sheets together but don't take the white ceiling layer off?

I once tested rigid fiberglass with a facing on both sides and it was not as good as with a facing on one side only. I never tried what you described, but I have to think it will be worse than no facing or facing on only one side. But there's no way to know for sure other than to test it. I will say that removing the facing is not difficult. It peels right off. Go ahead get your hands dirty!

--Ethan

[joeq]

Originally Posted by Ethan Winer

Go ahead get your hands dirty!

--Ethan

just don't rub your eyes with those dirty hands...

[partnering]

okay i went and got 2 cases of this stuff. its like 9.5 inches thick for the whole case.

the facing seems to peel quite easily off. as easy as say velcro. the box has cardboard around the edge but the sides are bare. the entire thing is wrapped in plastic tho. Right now its in my driveway and i'm not bringing it in till i find some material to wrap the whole box. Once i clean up my room i am going to bring in box and put it on the two corners by my monitors catacorner and see what happens. Its still unopened so i can always return it with receipt . If i decide to make some 2 inch panels it doesn't look hard to peel the facing off and wrap 2 inches in material i don't think. It not fun handling hte stuff tho. it itches abit. To tell you the truth i don't understand how this material which seems not really dense at all can do what it does.

[danasti]

Originally Posted by partnering

It not fun handling hte stuff tho. it itches abit. To tell you the truth i don't understand how this material which seems not really dense at all can do what it does.

You should wear plastic disposable gloves when touching fiberglass and possibly a mask so you don't breath it in.

I don't have any experience with the stuff you bought but 705 is denser than 703. 4 inch thick - 2 foot wide - 8 foot high should make a good corner trap. Cover it in burlap and angle it in the corner - it works great and it's very inexpensive - about $75 per corner.

[partnering]

my mom doesn't want it in the house so i have to return it. I guess i'll have to wing it.