Best Density?!?

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filete

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Hi there!
With so many options, I am really confused!
I need to make 10 broadband absorver and 6 bass traps.
I will be using Rockwool, but want to make sure to get the best density.
So, questions:

1 - What density should I get for the Broadband Absorver?
And for the bass traps?

2 - Its 100mm for the bass traps and 50mm or 40mm for the broadband
a good thickness?

Hope to have an answer soon,
Thanks
:)
 
Dude! In all my internet surfing I have never came accross this. Nice/Thank you
 
I´ve read that page, but can´t figure out what´s the best option,
for each panel...
:confused:
 
705 is generally a little better for bass absorbtion than 703, however 703 is cheaper than 705 so it is better bang for the buck. So my experience is to just get a whole bunch of 703 and vary your thickness as needed. Remember you can't really absorb more than all.
 
filete said:
Hi there!
With so many options, I am really confused!
I need to make 10 broadband absorver and 6 bass traps.
I will be using Rockwool, but want to make sure to get the best density.
So, questions:

1 - What density should I get for the Broadband Absorver?
And for the bass traps?

2 - Its 100mm for the bass traps and 50mm or 40mm for the broadband
a good thickness?

Hope to have an answer soon,
Thanks
:)


For your Bass traps a minimum of 100mm thick with an air gap behind is preferrable, and the Broadband absorbers can be 50mm thick with an air gap behind also.
 
Gorty said:
For your Bass traps a minimum of 100mm thick with an air gap behind is preferrable, and the Broadband absorbers can be 50mm thick with an air gap behind also.

How about the density/m3?
I was thinking of 40Kg for the broadband, and 70Kg for the bass...
I dont want to start to get reflections for using the wrong density!
:confused:
 
filete said:
How about the density/m3?
I was thinking of 40Kg for the broadband, and 70Kg for the bass...
I dont want to start to get reflections for using the wrong density!
:confused:
You won't, You will just have to make your bass traps a little thicker for the 703 but since the 703 is less expensive that is no problem.
 
Innovations said:
You won't, You will just have to make your bass traps a little thicker for the 703 but since the 703 is less expensive that is no problem.

Sorry, but I can´t find Owens Corning 700 series Rigid Fiberglass on Europe,
so I will be using Rockwool.
Again, can you tell me the ideal PCF value for broadband and bass traps?

Thanks
 
> What density should I get for the Broadband Absorver? <

I'd say 6 pcf is probably ideal. See this page:

www.ethanwiner.com/density/density.html

Note that these tests show what happens well below the 125 Hz lower limit for standard published data. So my tests are much more useful.

--Ethan
 
filete said:
Sorry, but I can´t find Owens Corning 700 series Rigid Fiberglass on Europe,
so I will be using Rockwool.
Again, can you tell me the ideal PCF value for broadband and bass traps?

Thanks
The numbers for rock wool and fiberglass are virtually identical.

703= 3 pounds per cubic foot. 705=5 pounds per cubic foot. The 5 is better for bass absorbtion but the 3 is cheaper. So for example a 3 inch 705 absorber will get you about the same bass absorbency as a 4 inch 703 absorber. So I usually just get a bunch of one inch 703 and layer it up for whatever I need.
 
Ethan Winer said:
> What density should I get for the Broadband Absorver? <I'd say 6 pcf is probably ideal...
--Ethan
:confused:
6 PCF for broadband?!?
Now I am really confused!
I asked for help also on Recording Studio Design "Forum",
and here ´s what people are saying:
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=4852

I need to go tomorrow to the store pickup the rockwool for the panels,
so I dont want to bring the wrong ones...
Because the PCF values for rockwool in Europe are different from US,
so the closer I can get at this time of the year is:

PN70 (70Kgs PCF) with 100 mm for Bass Traps
PN55 (55Kgs PCF) with 40 mm for Broadband Absorver.

Some people say it should be fine, close to ideal
but with Ethan opinion it just made me more confused!

Help, please...
 
> I asked for help also on Recording Studio Design "Forum", and here´s what people are saying: <

You know what they say about opinions - and everybody has one!

I have my company's MicroTraps (based on 705) at the first reflection points in my home theater, and they work very well. I think one of the problems with opinions is too many people parrot what they read, and don't have enough direct personal experience. This is not to impugn the guys at John Sayers' site! But I can tell you for sure that 6 pcf is fine. Moreover, you asked about broadband, which includes the bass range. However, if you had asked about first reflection panels only I'd have said that 703 is fine.

--Ethan
 
Yes, Ethan!
I was talking about first reflection panels, not broadband.
Sorry, my mistake.

703 comes in different PCF, whats should be ideal for first reflection panels?
 
I don't try to sound like a dumbass but, I have worked in many studios, built 2 of my own and have never had the need for a bass trap. I see a lot of talk on several forums about this. May be it is room design to begin with, I've never had to mix or record in a square room, there have been many 22.5 and 45 deg. angles.....also I always use my own monitors wherever I work..............am I ignorant or fortunate that the rooms I work in are ok to begin with?
 
filete,

> 703 comes in different PCF, whats should be ideal for first reflection panels? <

703 is 3 pcf, and 705 is 6 pcf. Theoretically 703 will be a little better for first reflections, but in practice it doesn't really matter. Heck, in theory fluffy fiberglass 3 to 6 inches thick would be better still, but it's more difficult to make fluffy fiberglass look nice on a wall.

--Ethan
 
jp,

> never had the need for a bass trap ... am I ignorant or fortunate <

Ignorant may be too strong, but misinformed and unaware of what's possible certainly applies. :D

Seriously, if you've had several rooms and none of them had bass traps, then I'd say you're missing something very important without even realizing it. Likewise for listening in a reflection free zone. Both of these acoustic treatments help you to hear what's in a mix much more clearly. This is not to say it's impossible to make a good mix without bass traps and RFZ treatment. But you have to work a lot harder, and you have to experiment much more playing back on different speakers and in the car etc. Once you mix in a properly treated environment all of a sudden it's much easier, and much more fun, and you can get a much better mix more quickly.

--Ethan
 
hey Ethan,

given your test results were limited to that rooms particular modes, would you expect any significant deviation from those results in other rooms? say where the predominent frequency was 32hz and 64hz? I'm guessing that the results in another room would be pretty much the same...
 
Innovations said:
...So I usually just get a bunch of one inch 703 and layer it up for whatever I need.

What´s the best way to layer them up in a frame?
Should I use any kind of glue?
And I was told that layer up several panels to get 100mm, does
not make the same acoustic effect as get only one panel with 100mm!
Is this true?
 
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