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The Mother of Acoustic Treatment
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Tomos
IsraTrance Full Member
Started Topics :
84
Posts :
981
Posted : Apr 13, 2008 14:48
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On 2008-04-13 06:17, particle velocity wrote:
Make sure your speakers are at least 12 to 24 inches off the wall and (NOT LAYING SIDEWAYS)
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Unless you've got speakers designed to be sideways 
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gutter
Inactive User
Started Topics :
54
Posts :
3018
Posted : Apr 16, 2008 10:57
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| Unless you've got speakers designed to be sideways |
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doesnt make sense ? are there monitors like that ? what do you mean , that these monitors do not have reflections when laying on the wall??
thats impossible
this placement will give huge early reflections
, fron what im thinking
anyway i havent see something like that , maybe you could show some 
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Get-a-fix
Getafix
Started Topics :
147
Posts :
1441
Posted : Apr 16, 2008 12:37
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vegetal
Vegetal/Peacespect
Started Topics :
19
Posts :
1055
Posted : Apr 16, 2008 14:07
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gutter
Inactive User
Started Topics :
54
Posts :
3018
Posted : Apr 16, 2008 16:07
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| Build or buy a helmholtz resonator instead. |
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Helmholtz resonator is great , Im gonna build one too
check this site from Nederlands
http://www.mhsoft.nl/Helmholtzabsorber.asp
Explains everything on building everything
included frequency , dimensions , density calculators , etc .. !! |
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vegetal
Vegetal/Peacespect
Started Topics :
19
Posts :
1055
Posted : Apr 16, 2008 17:14
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On 2008-04-16 16:07, gutter wrote:
Quote:
| Build or buy a helmholtz resonator instead. |
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Helmholtz resonator is great , Im gonna build one too
check this site from Nederlands
http://www.mhsoft.nl/Helmholtzabsorber.asp
Explains everything on building everything
included frequency , dimensions , density calculators , etc .. !!
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Hey Gutter have you found any info on how to place the holes when you make a helmholtz panel resonator or what material to use inside the resonator since he says "However, predicting the performance of these traps is difficult because the Q or bandwidth varies depending on the amount of internal damping." ?
 Demand recognition for the Armenian genocide 1915
http://www.devilsmindrecords.org/
http://www.myspace.com/vegetalmusic
http://www.checkpoint-music.com/ |
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gutter
Inactive User
Started Topics :
54
Posts :
3018
Posted : Apr 17, 2008 14:30
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again for the material from what i can think you go for rockwool / fiberglass absorption
cause they say "absorbent material" & best materials are those two . i dont know though what kind of density to use , cause inside the resonator maybe low density ex.50kg of rockwool
or the 703 maybe (?) or even lower rockwool density so that there is space & air to move , think its not the same as plane basstraps,
As for the holes ,
theres another problem , we have to buy omnidirectional mics and make measurements in the exact space , generally inside the room etc , to find the resonant frequencies
& the make calculations with the calculator ,except from the online calc. , this site gives a free one for PC , it is really great , very helpful
http://www.mhsoft.nl/user/acoustic%20calculator.asp
and an Absorption FactorS in excel document , you can take it from here, http://rapidshare.com/files/108187608/abstab_wf.xls.html
anyway there an issue with that and this kind of treatment cant go blind , it needs measurement , it targes to very specific points , where sometimes you might not need to treat those frequencies
4 example if you put in the calc. these values :
Panel area [m2] 1
Panel thickness [cm] 1
Depth of the air space [cm] 20
Hole diameter [mm] 15
Amount of holes 50
you have :
Percentage of perforation [%] 0.88
Resonant frequency [Hz] 71.99
so you target there..
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gutter
Inactive User
Started Topics :
54
Posts :
3018
Posted : Apr 17, 2008 14:33
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| Demand recognition for the Armenian genocide 1915 |
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Dharma Lab
Started Topics :
8
Posts :
342
Posted : Apr 17, 2008 21:08
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On 2008-04-16 14:07, vegetal wrote:
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On 2008-04-03 21:31, Dharma Lab wrote:
I've been researching for months, & all sources say the same thing, if you want to tame bass response, foam just doesn't cut it, you have to use thick, like insulation.
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Build or buy a helmholtz resonator instead.
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Interesting read about the helmholtz resonator. I see them very much as the last link in the chain, as they only target very specific frequencies. A broad-band absorber has always been the first step in everything I've read, then apply very specific treatment like the helmholtz resonator, diffusors, etc, if necessary.
For mid & high band absorption, most recommedations I've seen is 2" to 4" thick, at a desity of 3 PCF (pounds per cubic foot).
For Low, mid & high broadband absorption, most of the recommendations I see are 4" - 8" thick, at densities of 5-8 PCF.
Basic idea: for good low, mid & high end absoprtion, the less dense the material, the thicker you need it. Keep The Faith,
Christian K. |
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gutter
Inactive User
Started Topics :
54
Posts :
3018
Posted : Apr 18, 2008 16:29
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.. i wonder ,, still this calculator dont give the absorption factor of the inside material to calculate with .. so this varies too
naverending story 
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Adharaguy
IsraTrance Junior Member
Started Topics :
37
Posts :
138
Posted : Apr 21, 2008 16:27
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illusions
Erebus
Started Topics :
40
Posts :
626
Posted : Apr 21, 2008 16:39
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On 2008-04-13 06:17, particle velocity wrote:
Make sure your speakers are at least 12 to 24 inches off the wall and (NOT LAYING SIDEWAYS)
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Whats wrong with placing monitors sideways ? |
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Dharma Lab
Started Topics :
8
Posts :
342
Posted : Apr 22, 2008 22:27
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On 2008-04-21 16:39, illusions wrote:
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On 2008-04-13 06:17, particle velocity wrote:
Make sure your speakers are at least 12 to 24 inches off the wall and (NOT LAYING SIDEWAYS)
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Whats wrong with placing monitors sideways ?
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It has to deal with the amount of offset between the tweeter & woofer. Think of it this way, if you lay the monitor sideways with the woofers on the outside, & the tweeters on the inside, & start all the way at your left: as you move from left to right you'll be closest to the woofer first, then a small sweetspot where you are equa-distant from both, then you'll be closest to the tweeter as you cross over to the right side of the monitor. So, there is a lot more variation of your proximity to each sound source (i.e. the tweeter as one sound source, and the woofer as the other).
The same think happens when you have your monitors upright & you move vertically. But, chances are you are going to be moving horizontally a lot more when you work than you will move vertically.
Some speakers are designed to be laid sideways, and so I imagine they engineer to account for all of this in some fashion. For example, some speakers have a much better 'off axis' frequency response than others, so being off axis doesn't make as large of a difference.
It's all pretty simple to test. Just put the monitor in a veritcal or horizontal position & move your head around horizontally & vertically to see how the sound changes. The idea is you want to minimze the sound change in the directions you are moving the most often.
Keep The Faith,
Christian K. |
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Suloo
IsraTrance Full Member
Started Topics :
87
Posts :
2822
Posted : Apr 22, 2008 22:59
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DrUiWeIrD
Started Topics :
6
Posts :
19
Posted : Apr 23, 2008 03:31
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