#1647617 - 04/13/04 12:47 AM
70x Absorption
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Andre Vare
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Registered: 03/13/04
Posts: 125
Loc: Hamilton, ON Canada
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I have been reading many misunderstandings about the absorption efficiencies about Owens-Corning 703, 705, with or without FRK, and even today 707!
The following is a table of absorption coefficients for 703 (FG 3), 705 (FG 5) and Roxul RXL40 (RW 4) in thicknesses from 1 to 4 inches. The OC products are also included with FRK.
Type Thk FRK 125 250 500 1000 2000 4000
FG 3 1 no 0.03 0.22 0.69 0.91 0.96 0.99
RW 4 1 no 0.07 0.32 0.77 .99* .99* .99*
FG 5 1 no 0.08 0.25 0.74 0.95 97.00 0.99
FG 3 1 yes 0.12 0.74 0.72 0.68 0.53 0.24
FG 5 1 yes 0.18 0.73 0.43 0.58 0.39 0.30
FG 5 2 no 0.19 0.74 0.99 0.99 0.99 0.99
FG 3 2 no 0.22 0.82 0.99 0.99 0.99 0.99
RW 4 2 no 0.26 0.66 .99* .99* .99* .99*
FG 3 2 yes 0.51 0.65 0.86 0.71 0.49 0.26
FG 3 3 no 0.53 0.99 0.99 0.99 0.99 0.99
FG 5 3 no 0.54 0.99 0.99 0.99 0.99 0.99
FG 5 2 yes 0.61 0.45 0.35 0.32 0.48 0.31
RW 4 3 no 0.63 0.95 .99* .99* .99* .99*
FG 5 4 yes 0.65 0.52 0.42 0.36 0.49 0.31
FG 5 3 yes 0.66 0.46 0.47 0.40 0.52 0.31
FG 5 4 no 0.75 0.99 0.99 0.99 97.00 0.98
FG 3 3 yes 0.84 0.88 0.86 0.71 0.52 0.26
FG 3 4 no 0.84 0.99 0.99 0.99 0.99 0.99
FG 3 4 yes 0.88 0.90 0.84 0.71 0.49 0.23
RW 4 4 no .99* .99* .99* .99* .99* .99*
Observations...
At any given thickness, for open faced material, the rockwool was superior, with the exception of 2" @250 Hz. For 1 and 2" thicknesses, the 705 FRK was best for low end absorption.
At every thickness the FRK shows its mid and high end roll off
At 1" thickness, the best low end absorption is with the 705 FRK. The worst was 703.
At 2" thickness, the best low end absorption at 125 Hz was with 705 FRK. The worst was 705.
At the 3" thickness, the 703 and 705 are identical for practical purposes, being the worst at low end. . The best performance is 703 FRK. The 705 FRK had worse low end absorption than the 703 FRK.
At 4" the best was the RW. The worst was 705 FRK. The 705 FRK has worse absorption than 3" of 705 FRK. The 703 FRK has slightly higher absorption @125Hz than 703.
Practical things:
703 FRK 2", 703 3" and 705 3" are the same at the low end.
705 FRK at 2, 3, and 4" does not have a significant difference in performance.
703 FRK 3" has the same low end performance as 703 4". If the extra inch isn't important,.compare the prices.
I hope this helps clear things up.
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#1647618 - 04/13/04 12:53 PM
Re: 70x Absorption
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Ethan Winer
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Registered: 06/12/00
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Loc: New Milford, CT, USA
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Andre,
Thanks for doing all that work. I'll try not to be too much of a wet blanket. 
One big problem with octave testing is it hides a lot of detail. Those tests also do not reflect what happens when the material is mounted spaced out from a wall or straddling a corner. But it's certainly better than no comparison!
--Ethan
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#1647619 - 04/15/04 01:18 AM
Re: 70x Absorption
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Jason Poff
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Registered: 05/11/01
Posts: 330
Loc: Lexington, Ky.UNITED STATES
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What does FRK mean? I found a 703/705 supplier here but my questions are lost on him. He's not the brightest. Not to mention his accent is completely unintelligible  .
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#1647620 - 04/15/04 01:24 AM
Re: 70x Absorption
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Jason Poff
Senior Member
Registered: 05/11/01
Posts: 330
Loc: Lexington, Ky.UNITED STATES
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#1647621 - 04/15/04 03:34 AM
Re: 70x Absorption
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Andre Vare
Senior Member
Registered: 03/13/04
Posts: 125
Loc: Hamilton, ON Canada
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Giber Re-enforced Kraft. The insulation has a layer of paper similar to grocery bag paper on one side.
Hope this helps and good lucj!
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#1647622 - 04/15/04 01:52 PM
Re: 70x Absorption
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Ethan Winer
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Jason,
FRK = Foil Reinforced Kraft paper.
As Andre explained, it's like the paper they use for grocery bags, but with an extremely thin layer of metal foil bonded to one side of the paper. The FRK paper is not intended for acoustic purposes, but to serve as a vapor barrier in homes. It just happens to be good acoustically too.
--Ethan
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#1647623 - 04/15/04 02:39 PM
Re: 70x Absorption
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Jason Poff
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Registered: 05/11/01
Posts: 330
Loc: Lexington, Ky.UNITED STATES
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I see. Thank you.
Jason
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#1647624 - 04/16/04 08:10 AM
Re: 70x Absorption
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Andre Vare
Senior Member
Registered: 03/13/04
Posts: 125
Loc: Hamilton, ON Canada
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Here is the original table reordered to how most people would want to use it. That is by product type and thickness.
One big problem with octave testing is it hides a lot of detail.
Those tests also do not reflect what happens when the material is mounted spaced out from a wall or straddling a corner.
But it's certainly better than no comparison!
Self congratulations mode on
Not to be vain, but I think this is much better than no comparison. Many people coming here are not familiar with where to get information, and this (especially when we get the FRK faced data) will provide one place to see the performance of all the commonly sound absorbent materials in all the common thicknesses in one place.
Self congratulations mode off.
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#1647625 - 04/16/04 11:00 AM
Re: 70x Absorption
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Dan C
Senior Member
Registered: 04/12/04
Posts: 186
Loc: Hampton, NH
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Andre,
Your contributions to this message board are very much appreciated. Only if we could add the Delta and Knauf products to the data comparison, then one could really make an informed buying decision.
I am very interested in the Roxul 3 inch RHF 40.
I called Roxul yesterday and was given the phone number of a sales rep in the Boston area. The numerous calls I made to that number went unanswered! So frustrating.
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#1647626 - 04/16/04 12:44 PM
Re: 70x Absorption
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Ethan Winer
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Posts: 5406
Loc: New Milford, CT, USA
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Andre,
> 3.0 pcf at 3 inches has better absorption than 4.5 pcf at 2"! <
Maybe, maybe not. The problem is this also needs to be tested with an air gap. I am not saying that data is wrong! But with an air space I suspect there's more going on than just pure gasflow resistance.
> I found your comment about one octave analysis having a big problem with hiding data somewhat confusing. Total agreement with that comment with regards to complex absorbers like the faced materials, but homogeneous materials have relatively predictable performance specs. <
Normal absorbing material measured in the normal way is indeed predictable. I think of it as a one-pole filter, where the low end rolloff starts at a given frequency and falls off linearly. But when a panel is spaced away from a wall, or when mounted straddling a corner, you get two or three "poles." This is all I was commenting on.
--Ethan
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#1647627 - 04/16/04 01:11 PM
Re: 70x Absorption
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Andre Vare
Senior Member
Registered: 03/13/04
Posts: 125
Loc: Hamilton, ON Canada
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Your contributions to this message board are very much appreciated.
Only if we could add the Delta and Knauf products to the data comparison, then one could really make an informed buying decision.
If you want to confirm that a given company's product is the same, then go to their website and compare the acoustic data to the table in this thread.
Having written that, I decided to do a comparison for two reasons: the chosen companies from from an outside person (No ringer by me), and to provide some discussion on comparing test data illustrate the similarities, what to look for, and what to ignore.
I am very interested in the Roxul 3 inch RHF 40.
I called Roxul yesterday and was given the phone number of a sales rep in the Boston area. The numerous calls I made to that number went unanswered! So frustrating.
Good Luck!
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#1647628 - 04/16/04 02:43 PM
Re: 70x Absorption
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Ethan Winer
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Registered: 06/12/00
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Loc: New Milford, CT, USA
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Andre,
> The products from different companies of a given type (eg. 3.0 pcf fiberglass board) are similar in acoustic properties. <
Yes, exactly. If you can't get OC then buy Roxul. Can't get Roxul? Then get Knauf. It's no big deal.
> as one goes lower in frequency, the variation in measurements becomes more and more affected by the physical characteristics of EACH SPECIFIC TEST FACILITY. <
Yes - and not just at low frequencies!
> So why didn't I include Delta? When I went to their website I could not find any acoustical data. <
I called them about a year ago, and they faxed me a data sheet. But they told me outright that I should take the data with a grain of salt because it was more "estimated" than measured.
--Ethan
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#1647629 - 04/16/04 02:52 PM
Re: 70x Absorption
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Dan C
Senior Member
Registered: 04/12/04
Posts: 186
Loc: Hampton, NH
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HEY HEY HEY!!!!!
I just got home with 3 bundles of Roxul RHT 80!
Paid .93/sf for 3 inch and .57/ft for 1 1/2 inch.
Better than christmas!!!
All I need is fabric and then the fun part starts-
fabricating, locating, experimenting and most of all - listening!
Peace,
Dan
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#1647630 - 04/16/04 03:24 PM
Re: 70x Absorption
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Andre Vare
Senior Member
Registered: 03/13/04
Posts: 125
Loc: Hamilton, ON Canada
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Dan:
Congratulations! would you be so kond as to post those prices in the thread dealing with material prices also? I think the title is similar to "703 prices". You made the find, I would you to get the credit for it.
Was it a standard price or some sort of end of run etc? The price is amazingly below what I have been seeing for 703 and RXL 40.
I will check the specs, but I think there is about to be a new thread tying in with using material.
As you do your treatment and listening, would you mind doing some test setups for different mountings? I will detail in another thread, trying to keep this one for detailing material specs.
Once again, Congratulations!
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#1647631 - 04/16/04 04:29 PM
Re: 70x Absorption
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Ethan Winer
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Registered: 06/12/00
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Dan,
> HEY HEY HEY!!!!! <
Fabulous. Don't wait for fabric. Go for instant gratification and just lean a bunch of the thicker panels against the walls and into the corners. Then play sme music and prepare to smile. 
--Ethan
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#1647632 - 04/16/04 06:43 PM
Re: 70x Absorption
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Dan C
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Registered: 04/12/04
Posts: 186
Loc: Hampton, NH
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I'M SMILING ALREADY!!!
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#1647633 - 04/16/04 07:49 PM
Re: 70x Absorption
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Dan C
Senior Member
Registered: 04/12/04
Posts: 186
Loc: Hampton, NH
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There are two different RHT 80 insulations made by Roxul, one is Architectural and the other Industrial. The packaging on mine does not specify which type I have. The Roxul web site
http://www.roxul.com/sw34127.asp only gives acoustical data for one of them?
Please tell they are both good for my application!
Already been to the fabric store this afternoon.
They had some burlap fabric but it was nothing I could put on the family room wall. I did find some muslin that looks great, is the perfect color, does not appear to be too tight a weave(I can blow through it) and best of all its only $2 bucks a yard!
Please tell me muslin is good!
Sorry Ethan, I am not the instant gratification type. As a matter of fact, the insulation is not even coming into the house until I get it wrapped with fabric.
Hopefully this weekend I can post an update on my progress.
Thanks again guys for this forum.
Dan
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#1647634 - 04/16/04 08:34 PM
Re: 70x Absorption
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Andre Vare
Senior Member
Registered: 03/13/04
Posts: 125
Loc: Hamilton, ON Canada
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I am not certain what the problem was, but I found data sheets for both lines on the Roxul website, but then again I have been going there so much lately that I know the principles of the layout almost as well as the back of my hand.
I d/led both and will look over the data sheets.
Am I reading this correctly between the lines? You purchased some material that was not detailed in any of the discussions here, and did not check the acoustical properties of it to see if it was applicable.
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#1647635 - 04/16/04 08:34 PM
Re: 70x Absorption
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Andre Vare
Senior Member
Registered: 03/13/04
Posts: 125
Loc: Hamilton, ON Canada
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I am not certain what the problem was, but I found data sheets for both lines on the Roxul website, but then again I have been going there so much lately that I know the principles of the layout almost as well as the back of my hand.
I d/led both and will look over the data sheets.
Am I reading this correctly between the lines? You purchased some material that was not detailed in any of the discussions here, and did not check the acoustical properties of it to see if it was applicable.
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#1647636 - 04/16/04 10:52 PM
Re: 70x Absorption
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Dan C
Senior Member
Registered: 04/12/04
Posts: 186
Loc: Hampton, NH
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Andre,
I did not know that there was two different RHT 80's until I got the stuff home.
If this is the wrong stuff I'll jump out a window.
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#1647637 - 04/16/04 11:53 PM
Re: 70x Absorption
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Andre Vare
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Registered: 03/13/04
Posts: 125
Loc: Hamilton, ON Canada
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What is the part number of the material? 15080 or 07210? My guess is that it is 15080.
Regardless, either WILL work. Just sit down, relax, and think of killing some marketing people.
I could not find a Canadian equivalent to the 07210, which does have acoustic data on its data sheet. The 15080 Canadian Data sheet DOES have acosutic data on it, unlike the US market data sheet. The diference between the two products is the binder used.
There might a problem with high end reflection. IF you could cut a wedge shape on patternon the surface, about an inch wide and an inch deep, this should counteract that by giving additional surface area for the sound to be absorbed.
Good luck!
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#1647638 - 04/17/04 12:12 PM
Re: 70x Absorption
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Ethan Winer
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Registered: 06/12/00
Posts: 5406
Loc: New Milford, CT, USA
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Dan,
> Please tell me muslin is good! <
Muslin is good.
--Ethan
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#1647639 - 04/17/04 01:23 PM
Re: 70x Absorption
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Dan C
Senior Member
Registered: 04/12/04
Posts: 186
Loc: Hampton, NH
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There might a problem with high end reflection. IF you could cut a wedge shape on patternon the surface, about an inch wide and an inch deep, this should counteract that by giving additional surface area for the sound to be absorbed.
?
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#1647640 - 04/19/04 10:31 PM
Re: 70x Absorption
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Dan C
Senior Member
Registered: 04/12/04
Posts: 186
Loc: Hampton, NH
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"There are two different RHT 80 insulations made by Roxul, one is Architectural and the other Industrial. The packaging on mine does not specify which type I have. The Roxul web site
http://www.roxul.com/sw34127.asp only gives acoustical data for one of them?"
"What is the part number of the material? 15080 or 07210? My guess is that it is 15080"
andre,
the tag on my roxul does not have those part numbers. I called the guy that sold it to me and he thinks the architechtural rht 80 and the industrial rht 80 are the same product. i would love to see the acoustical data on the "industrial" rht 80.
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#1647641 - 04/20/04 01:12 PM
Re: 70x Absorption
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Dan C
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Registered: 04/12/04
Posts: 186
Loc: Hampton, NH
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just received an e-mail from Roxul.
the industrial rht 80 has the same acoustical performance as the architechtural rht 80.
this makes me very happy!
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