Low kg/m3 is worthless.

[Gdupproductions]

Before the pro acousticians go and nagg on me .....This ropic is only based on my own expierience whitch i discovered so plz save me from theorys :D.

A year ago ive built a panel with rockwool 50kg m3 and placed this next to a speaker (reflection surface actually but i have a small room), And lord have mercy how everything whas so defined i even heard sounds in songs i even diden't know it whas there, but i removed everything and sold the insulation due you know and kept the room untreated......Now lately i started building a trap/traps with the ecose stuff i bought a long time ago its 16-20 kg m3 or so but as ive been reading the fluffy stuff gets only effective at a high thickness.So what i did is compress 200mm to 118 mm - Placed that panel at the same place like i did a year ago and i heard no diffrence, no NOTHING.

I took 1 sheet off insulation out and tried again but still no diffrence.
Realy people Don't buy fluffy or as they call it ATIC insulation.

I'm not even bothered with measurements, if a Change in sound isn't noticeable then it says enough i can even hear a ice cream truck from a mile away so im not deaff neither.

[explorer]

Fluffy insulation is normally only recommended in much thicker configurations (e.g. large filled corner chunks). In these cases it should not be compressed.

[PaulP]

Originally Posted by explorer

Fluffy insulation is normally only recommended in much thicker configurations (e.g. large filled corner chunks). In these cases it should not be compressed.

I believe the usual recommendation is for a minimum of 250 mm, uncompressed. 300mm and upward is better. In all cases you don't want to be too close to it.

[Gdupproductions]

Originally Posted by PaulP

I believe the usual recommendation is for a minimum of 250 mm, uncompressed. 300mm and upward is better. In all cases you don't want to be too close to it.

My room is only 1900mm in width .

[Max Dread]

TBH, it seems in this case that it is your understanding and application of the low density MW that is "worthless" - no the concept of suing it altogether.

On the plus side, at least it is cheap and it was therefore not an expensive mistake!

You're definitely best off sticking with the higher density material, as your experience has shown.

[Jens Eklund]

The important parameter when deciding which wool to use is the flow resistivity (kPa*s/m²) and this is not necessarily related to density although for normal mineral wool there is usually a relation.

Some simulations of a 200 mm panel with different flow resistivity using the Miki-model (which is an updated version of the empirical Delany-Bazley model):

[boggy]

Originally Posted by Jens Eklund

...........
Some simulations of a 200 mm panel with different flow resistivity using the Miki-model (witch is an updated version of the empirical Delany-Bazley model):
...

Did you modeled an air gap behind panel?


Cheers

Boggy

[Jens Eklund]

Originally Posted by boggy

Did you modeled an air gap behind panel?

No gap, just wool.

[boggy]

Originally Posted by Jens Eklund

No gap, just wool.

Thanks.

[Gdupproductions]

Originally Posted by Jens Eklund

The important parameter when deciding which wool to use is the flow resistivity (kPa*s/m²) and this is not necessarily related to density although for normal mineral wool there is usually a relation.

Some simulations of a 200 mm panel with different flow resistivity using the Miki-model (witch is an updated version of the empirical Delany-Bazley model):
Attachment 245731

Wel flowresistivety or not.....The rockwool i used before whas 50 kg/m3 and the fibreglass i use now has 16 kg/m3 as a Knauf co worker told me. and TBH the rockwool owned fibreglass like a Piñata.

[Gdupproductions]

Originally Posted by Max Dread

TBH, it seems in this case that it is your understanding and application of the low density MW that is "worthless" - no the concept of suing it altogether.

On the plus side, at least it is cheap and it was therefore not an expensive mistake!

You're definitely best off sticking with the higher density material, as your experience has shown.

40$ not a expensive mistake ?.....lol wish i could get it back. And Knauf doesn't have any Ecose products with a higher density. I've been searching for it like a lunatic before i bought the fmuffy stuff

[Jens Eklund]

Originally Posted by Gdupproductions

Wel flowresistivety or not.....The rockwool i used before whas 50 kg/m3 and the fibreglass i use now has 16 kg/m3 as a Knauf co worker told me.

What I’m trying to say is that different materials can have different flow resistivity even if the density is the same. Some time ago I sourced the FR for an eco-product of 30 kg/m³ but the FR was as low as 2,2 kPa*s/m².

[Gdupproductions]

Originally Posted by Jens Eklund

What I’m trying to say is that different materials can have different flow resistivity even if the density is the same. Some time ago I sourced the FR for an eco-product of 30 kg/m³ but the FR was as low as 2,2 kPa*s/m².

So the stuff i have should normally lay around 5000 rayls.....is it even usefull for anything ?. I have severe slap echo yess. But bass is a mutch more problem in my room then what so ever.

[Jens Eklund]

Did you see the graph in my previous post? 5-10 kPa*s/m² (Rayls/m) is usually a god value depending on thickness of the panel.

Also; velocity based absorbers need to be very tick to absorb efficiently in the lower bass region.

[Gdupproductions]

Originally Posted by Jens Eklund

Did you see the graph in my previous post? 5-10 kPa*s/m² (Rayls/m) is usually a god value depending on thickness of the panel.

Also; velocity based absorbers need to be very tick to absorb efficiently in the lower bass region.

Wel like i mentioned 200 insulation in a 140mm frame but its 118 due a smaller frame in the main frame. Im building the second frame 2 cuz thats the biggest i wanna go therefor i wanna compress the insulation in the frames i have a total off 12 slabs 50mm thick i wanna use 4 for each Trap and use the left overs for the front corner (chunks).

[Gdupproductions]

BTW if i could get the lower mids controlled then i'd be realy the happiest guy.....that's what i aim for. Cuz thats where my speakers suffer the most.

[Jens Eklund]

Treat your early reflection points (not just theoretical geometrical, but actual reflection points verified by ETC measurements) with as deep panels as possible, preferably 200 mm or deeper (or use geometry to redirect the early reflections). If you still have flutter echo, use geometry (splaying walls) or diffusers to redirect and prevent the repeating bounce. Remember that flutter echo does not necessarily need two parallel surfaces to occur. There can be a number of surfaces involved before the “loop” is closed and repeated.

[Gdupproductions]

Originally Posted by Jens Eklund

Treat your early reflection points (not just theoretical geometrical, but actual reflection points verified by ETC measurements) with as deep panels as possible, preferably 200 mm or deeper (or use geometry to redirect the early reflections). If you still have flutter echo, use geometry (splaying walls) or diffusers to redirect and prevent the repeating bounce. Remember that flutter echo does not necessarily need two parallel surfaces to occur. There can be a number of surfaces involved before the “loop” is closed and repeated.

Wel my right wal is less nakid cuz i have a cork board hanging there for my papers and stuff, and right behind me a small book case .But on the left side it's only a big nakid wall with a TV-wall mounted. When i place the panel in between the TV and speaker and clap my hands i hear echo coming from the back but no DEFINITION from that 1 speaker where the panel is next to, i did got a more clear sound with the rockwool. That's something i don't understand.

Do i need to add another slab off insulation in the frame ?. I've spend 40$ on this kanuf stuff and i don't wana throw it away tough =S, make it work for what so ever.

[Jens Eklund]

You need to make some measurements, analyze the ETC and figure out where the reflections are coming from. Placing panels by guessing is a waist of time and money.

[DanDan]

Knauf do 50KG Ecose Batts.
Have a friend hold a panel and move to block the flutter echo suspected surfaces. Flutter in a treated room tends to be very specific, easily found and easily fixed.
There is plenty of respected advice saying that thick low density fibre traps do well. Perhaps the most convincing one is Andre's NASA test.
However there is also info out there stating that density over a 4 to 1 range shows little change in absorption.
The original SuperChunks over at Studiotips.com were mostly 703, 48KG.
As they were tested and the lighter fibre was not, many of us are inclined to go with the proven.
It would be nice to see some absorption tests on Sheeps Wool.
DD

[Gdupproductions]

Originally Posted by Jens Eklund

You need to make some measurements, analyze the ETC and figure out where the reflections are coming from. Placing panels by guessing is a waist of time and money.

Why taking measurements if if there isn't any change in sound noticeable ? . I've took advice from here on the forum and it just busted me in the n*t. All i can say is only use the rigid stuff for acoustic treatment. The lower you go the less you acn do with it.

[Gdupproductions]

Originally Posted by DanDan

Knauf do 50KG Ecose Batts.
Have a friend hold a panel and move to block the flutter echo suspected surfaces. Flutter in a treated room tends to be very specific, easily found and easily fixed.
There is plenty of respected advice saying that thick low density fibre traps do well. Perhaps the most convincing one is Andre's NASA test.
However there is also info out there stating that density over a 4 to 1 range shows little change in absorption.
The original SuperChunks over at Studiotips.com were mostly 703, 48KG.
As they were tested and the lighter fibre was not, many of us are inclined to go with the proven.
It would be nice to see some absorption tests on Sheeps Wool.
DD

They probally cost like €60 or what not. I've payed €26 for mine.

[DanDan]

A friend recently bought some Knauf 50KG Universal Slabs.
€40 for a pack of nine batts. Each one is 50 x 600 x 1200
Seems very cheap eh?
DD

[Gdupproductions]

Originally Posted by DanDan

A friend recently bought some Knauf 50KG Universal Slabs.
€40 for a pack of nine batts. Each one is 50 x 600 x 1200
Seems very cheap eh?
DD

Where from ?........around here they only sell Ecose rolls. No bats.

[DanDan]

He found them locally. This is a small city on a small rock in the atlantic.
Lucky I guess, but more likely that it is because all the other insulation suppliers have gone bust, leaving just one. G and B insulations.
Thus they stock a good range.
The Rock ones used to be called Rocksilk before Ecose, thus the RS60 and so one.

Rock
Universal Slab (Rock)

Glass
Knauf Insulation Earthwool Universal Slabs (Glass) (05C) | Encon Insulation Ltd - insulation distributor, thermal and acoustic insulation, drywall, fire protection, roofing

DD

[Gdupproductions]

Originally Posted by DanDan

He found them locally. This is a small city on a small rock in the atlantic.
Lucky I guess, but more likely that it is because all the other insulation suppliers have gone bust, leaving just one. G and B insulations.
Thus they stock a good range.
The Rock ones used to be called Rocksilk before Ecose, thus the RS60 and so one.

Rock
Universal Slab (Rock)

Glass
Knauf Insulation Earthwool Universal Slabs (Glass) (05C) | Encon Insulation Ltd - insulation distributor, thermal and acoustic insulation, drywall, fire protection, roofing

DD

I've been to 5 - 6 diffrent stores.....for building supplys and none off them had Ecose until i bounced up on a Big stockage building that receive supplys with ships and they only had the ecose stuff that i bought.

So it's hard to get for me.

[Jens Eklund]

Originally Posted by Gdupproductions

Why taking measurements if if there isn't any change in sound noticeable ? . I've took advice from here on the forum and it just busted me in the n*t. All i can say is only use the rigid stuff for acoustic treatment. The lower you go the less you acn do with it.

One last time; density is not the figure of interest, it’s the flow resistivity value.

Oh, and why take measurements ... ?

[PaulP]

Originally Posted by Gdupproductions

. I've took advice from here on the forum and it just busted me in the n*t. All i can say is only use the rigid stuff for acoustic treatment. The lower you go the less you acn do with it.

No one around here suggested you use a thin layer of light insulation. You are the one who did not fully understand the subject (nothing wrong with that) and then made an error of application. Learn from your mistakes :-)

[Gdupproductions]

Originally Posted by Jens Eklund

One last time; density is not the figure of interest, it’s the flow resistivity value.

Oh, and why take measurements ... ?

Flow resistivety or not my friend .....i just know that the more dense stuff whas way beter.

And yess mesurments have to be taken to know the situation off my room which is horrible.

[Gdupproductions]

Originally Posted by PaulP

No one around here suggested you use a thin layer of light insulation. You are the one who did not fully understand the subject (nothing wrong with that) and then made an error of application. Learn from your mistakes :-)

200mm insulation 4 slabs off 50 into a frame off 140mm/118 due smaller frame is THIN ?....in a room off 1.90m wide. I'm even glad i can still move .