Author Topic: Group buy for some fibreglass / rockwool  (Read 5926 times)

Offline Phase

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Re: Group buy for some fibreglass / rockwool
« Reply #30 on: February 19, 2015, 08:19:32 PM »
Abu when are you thinking of ordering?

Offline Abu

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Re: Group buy for some fibreglass / rockwool
« Reply #31 on: February 19, 2015, 08:24:36 PM »
Not sure .. still waiting on some pricing and doing some additional research in the mean time

Offline Atjan

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Re: Group buy for some fibreglass / rockwool
« Reply #32 on: February 19, 2015, 11:34:06 PM »
From Bob Gold's Absorption Coefficients site:

Product    thickness    density                                   125hz    250hz    500hz    1000hz    2000hz    4000hz    NRC

AFB             1" (25mm) 3.0 pcf (48 kg/m3)         0.14       0.25      0.65    0.90    1.01    1.01       0.70
RXL 40    1.5" (25mm) 4.9 pcf (79 kg/m3)         0.18       0.48      0.96    1.09    1.05    1.05       0.90
RXL 60    1.5" (25mm)  6.0 pcf (96 kg/m3)        0.17     0.62         1.00    1.05    1.01      1.01    0.90
RXL 40    2" (51mm) 4.0 pcf (64 kg/m3)          0.26         0.68        1.12    1.10    1.03    1.04      1.00
RXL 60    2" (51mm)  6.0 pcf (96 kg/m3)          0.32       0.81       1.06    1.02    0.99    1.04       0.95

RXL 40    3" (75mm) 4.0 pcf (64 kg/m3)          0.63        0.95          1.14    1.01    1.03    1.04        1.05
RXL 60    3" (75mm) 6.0 pcf (96 kg/m3)         0.78        0.89        1.04    0.98    1.01    1.02        1.00

RXL 40    4" (100mm) 4.0 pcf (64 kg/m3)        1.03         1.07       1.12    1.04    1.07    1.08        1.10
RHT 80    4" (100mm) 5.9 pcf (94 kg/m3)        1.00         0.95      1.06    1.04    1.06    1.08       1.05

So basically:
- denser and lighter are all useless at 25mm for 125Hz
- at 50mm thick denser is better at bass but not much.
- at 75mm denser is still better than less dense,
- at 100mm thick both are equally good, in fact the lighter material is now the better absorber of the two.

If this trend continues at lower frequencies, I'm guessing 200mm thick 64kg/m3 material will be plenty for a corner trap.

Based on that, I'd be in for a couple of 100mm thick 64kg/m3 panels. To me the denser ones is past the point of diminishing returns.
« Last Edit: February 19, 2015, 11:43:28 PM by Atjan »
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Offline Doge

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Re: Group buy for some fibreglass / rockwool
« Reply #33 on: February 20, 2015, 12:07:53 AM »
If this trend continues at lower frequencies, I'm guessing 200mm thick 64kg/m3 material will be plenty for a corner trap.

This was basically my reasoning, if you look at the Owens Corning with a 40cm air gap 701 seems to outperform 703 and 705 at 125Hz at anything more than 5cm thick

I know for 4" thick straddled panels Ethan says 705, others say 703, is 701 the most efficient way to go for super-chunks? Although if you at these Rigid Fiberglass Density Tests it seems that density does seem to work a little better in a practical application; I'd still be happy to pay 70% to get 90% performance though...

I suppose the big problem is how do we know if EnergyLite 48 is really a 701 equivalent, or that Uthermo 6 is similar to Roxul 40 in terms of absorption?

Offline Atjan

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Re: Group buy for some fibreglass / rockwool
« Reply #34 on: February 20, 2015, 10:23:22 AM »
This was basically my reasoning, if you look at the Owens Corning with a 40cm air gap 701 seems to outperform 703 and 705 at 125Hz at anything more than 5cm thick

I know for 4" thick straddled panels Ethan says 705, others say 703, is 701 the most efficient way to go for super-chunks? Although if you at these Rigid Fiberglass Density Tests it seems that density does seem to work a little better in a practical application; I'd still be happy to pay 70% to get 90% performance though...

I suppose the big problem is how do we know if EnergyLite 48 is really a 701 equivalent, or that Uthermo 6 is similar to Roxul 40 in terms of absorption?
I agree, for the same type of material, there's use differences on Bob's site.

As to Ethan's test, I think if he were to test even thicker traps, the less dense ones would start to become more effective, such as is seen in the 125Hz test. Ethan was particularly interested in the 41Hz node and he only went to 150mm thick. He also mentions that the density becomes less important as the thickness goes up.
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Offline Timber_MG

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Re: Group buy for some fibreglass / rockwool
« Reply #35 on: February 20, 2015, 11:05:33 AM »
Rockwool has a much larger varience in air flow resistivity and tortuosity (primary variables in determining usefulness in acoustics) than fibre glass. From my experience I would order U thermo one step more dense than what a model would predict.

Isover Sweden had some data that was superior to OC at the same density, but one never knows how that translates to SA.

Offline Doge

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Re: Group buy for some fibreglass / rockwool
« Reply #36 on: February 20, 2015, 01:49:38 PM »
Mm... not inspiring my confidence for for the mineral-fibre types. I'm remembering why I opted for Energylite last time.

Since we've established cost seems directly related to weight, I might point out that Rockwool seems to be the cheapest per kg, with U Thermo being the most expensive.

I'm only looking an Insuplro prices here, I remember Egoli being a bit cheaper for Energylite as well.

Offline Abu

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Re: Group buy for some fibreglass / rockwool
« Reply #37 on: February 20, 2015, 02:40:28 PM »
Still waiting for more pricing.. but here's a little update so long:


                                    insulpro   aeroinsul   egoli     
uthermo 3 - 25mm   R 53.27      R 46.17      R 45.32     
uthermo 6 - 25mm   R 79.36      R 68.40      R 68.12     
uthermo 8 - 25mm   R 105.34   R 91.20      R 89.49     


                                    insulpro   aeroinsul   egoli     
uthermo 3 - 100mm   R 236.50   R 184.68   
uthermo 6 - 100mm   R 352.21   R 273.60   
uthermo 8 - 75mm   

energylite                        insulpro   aeroinsul   egoli   
47.5 - 25mm                     R 61.92                     R 43.87
64 - 25mm                     R 80.79                     R 146.30  <-- This looks wrong (have queried it)
96 - 25mm                     R 110.50         

energylite               insulpro         aeroinsul         egoli   
47.5 - 50mm                                                   R 89.42
64 - 50mm                                                   R 115.56
96 - 50mm                      



Then insulproducts also have a locally manufactured item called insulboard with the following prices per density:
     
40mm insulboard                 
80kg   R 78.83                                           
100kg   R 98.58                                     
120kg   R 118.31   


The suppliers seem to be on a go slow ....   even saint-gobain  :headbanger:

Offline Rodney_gold

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Re: Group buy for some fibreglass / rockwool
« Reply #38 on: February 20, 2015, 03:09:39 PM »
i got my 100 sheets of energylite 25mm 47.5 today from saint grobain
Im probably going to use 80 sheets , so will have some over and most likely havesome acoustic solution panels to go along with it.
Also have 30 x slat diffusion panels , 30x30cm x 100mm , 2 large slat diffusion panels 1200 x 600 , 6 x 1200 x 600 100mm absorbers , some thick stuff for chunk traps , 8 x tubular traps  and some curved 1200x 600 panels with red fabric and foam..
CT only tho , this stuff cant be shipped
Roon/tidal > Squeezebox touch> 2x Devialet D premiers>  Vivid audio Giya G1 spirits ..fully treated room

Offline Rodney_gold

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Re: Group buy for some fibreglass / rockwool
« Reply #39 on: February 20, 2015, 03:48:48 PM »










Roon/tidal > Squeezebox touch> 2x Devialet D premiers>  Vivid audio Giya G1 spirits ..fully treated room

Offline reactor_sa

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Re: Group buy for some fibreglass / rockwool
« Reply #40 on: February 20, 2015, 07:23:16 PM »
Rodney_gold, please relocate to joburg

Offline Abu

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Re: Group buy for some fibreglass / rockwool
« Reply #41 on: February 23, 2015, 02:37:45 PM »
Apparently Isover / Saint Gobain is offline since last week ..  hence the delay in getting the pricing.

Offline Abu

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Re: Group buy for some fibreglass / rockwool
« Reply #42 on: February 23, 2015, 09:43:12 PM »
Saint Gobain came through. Jay from egoli on the other hand must be swamped as he did not.


Loaded it on google sheets for anyone wanting to check it out:

https://docs.google.com/spreadsheets/d/1U-kh6dxTB7cJiDh8z2uyQrxbDQxSq1n5hxvhkHwTI3I/edit?usp=sharing

Pricing is on the left, some of my calcs are on the right.

Offline Rotten Johnny

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Re: Group buy for some fibreglass / rockwool
« Reply #43 on: February 23, 2015, 09:48:52 PM »
Shoowee, the stuff's gone up.
Audiophile: There is almost no other group that prides themselves more on wasting good money on utterly worthless ****, and then trying to furiously blow smoke up their own ass to justify it.

Free your mind...and your ass will follow.

Offline Doge

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Re: Group buy for some fibreglass / rockwool
« Reply #44 on: February 23, 2015, 10:59:54 PM »
Pricing is on the left, some of my calcs are on the right.

Thanks for this :thumbs: didn't know they made Energylite 80

I think you might want to do you corner trap calculations using a set thickness per product, price and usefulness doesn't really change drastically by getting 25mm instead of 50mm or vice versa so just pick one to make you life easier. 1" of anything is NOT going to do much in a corner, seems you need at least 75mm to get the slightest bass absorption at all, and 100mm is a worthwhile pay-off over that, 150mm a little more still.

Might also be useful to add corner chunk traps, you cut the batts into quarters and lay them flat, so a 25mm batt is only good for 100mm height, i.e., 24 batts per corner; this is where the lightweight stuff really comes in, Energylight 24 might even work, but it's seems like a heck of a gamble with the lack of info.