The No.1 Website for Pro Audio
 All  This Thread  Reviews  Gear Database  Gear for sale     Latest  Trending
Pro's & Con's of Absorber Types
Old 7th May 2009
  #1
Gear Head
 

Pro's & Con's of Absorber Types

Hi Guys!

I've been doing a lot of research as i'm about to build a room full of absorbers. I'm wanting to know if anyone can give me some advice on the best design.

The 2 main designs i've seen are these two...

John Sayers' Recording Studio Design Forum • View topic - Acoustic Panel Photo Essay

John Sayers' Recording Studio Design Forum • View topic - The 25 minute, $25 acoustic panel (or $42.00 bass trap)

Obviously the second one involves a lot less work but will either of these be more effective than the other?

Whichever way i do this they will be 10cm/4" thick!

Thanks thumbsup
Old 7th May 2009
  #2
Gear Guru
 
Glenn Kuras's Avatar
Your looking at pretty close the some, but the first one will give you a much cleaner look.

Glenn
Old 7th May 2009
  #3
Gear Head
 

Thanks Glenn!

Other than looks will there be much difference? Will the extra wood on the first design mean less absolbtion? Or are we talking measures too small to notice?

I do want them to look sharp but i also like the idea of them weighing less and being easier to mount on the corners where the walls meet the roof.

Just thinking out loud really! Thanks for the help! thumbsup
Old 7th May 2009
  #4
Gear Guru
 
Glenn Kuras's Avatar
Quote:
Other than looks will there be much difference? Will the extra wood on the first design mean less absolbtion? Or are we talking measures too small to notice?
In is impossible to say without building both and testing it, but yes the one with the open sides should preform better. How much? Well that is what a lab is for.
Old 7th May 2009
  #5
Quote:
Originally Posted by Glenn Kuras View Post
Your looking at pretty close the some, but the first one will give you a much cleaner look.

Glenn


The butt-joint with staples bothers me on that second one.... Other than that, it seems pretty easy resonably good looking.

On the first one, putting in 4 45deg corners will be a lot stronger.




-tINY

Old 8th May 2009
  #6
Gear Head
 

Thanks guys!

Yeah i'm not sure about the staples on that design too, i have glue and corner brackets and am only planning on using the stapler for the fabric

thumbsup
Old 8th May 2009
  #7
Gear Maniac
 

I am in the same state of considering how to treat a room. I agree with the comments so far and would like to point out that spacing the panels 3-4" from the back wall would make a world of difference in absorption, especially in the low-mid range.

Another point I'd like to comment on:
Quote:
as i'm about to build a room full of absorbers
This was my original approach as I started my research. Two months later and after reading four books and researching the subject, I've come to realize that there can be "too much" absorption in the room, especially if all walls and the ceiling are covered.

Absorption must be added to the room to reduce the decay time. In a small empty room with plastered concrete walls the decay time can easily be in the range of 1.5 ~ 2.5 seconds with some frequencies (typically the modal ones) having even longer decay times.

Absorption should be used to bring down the average decay time to the required figure (say 0.3 ~ 0.6 seconds depending on function).

It is really worthwhile to investigate the use of diffusers (something I was discounting at the beginning) and a couple of tuned absorbers for the offending modes that lie in the 40 ~ 80Hz range where porous absorbers can't really be as effective unless they start to occupy part of the room. I am considering a 2D diffuser for the back of the room and a combined cloud with absorption in the front and a skyline diffuser in the back.

I don't pretend to be an expert on the matter and I would welcome the more experienced to comment on my points.
Old 8th May 2009
  #8
Gear Guru
 
Glenn Kuras's Avatar
Quote:
Originally Posted by SaSi_SiDi View Post
I am in the same state of considering how to treat a room. I agree with the comments so far and would like to point out that spacing the panels 3-4" from the back wall would make a world of difference in absorption, especially in the low-mid range.

Another point I'd like to comment on:

This was my original approach as I started my research. Two months later and after reading four books and researching the subject, I've come to realize that there can be "too much" absorption in the room, especially if all walls and the ceiling are covered.

Absorption must be added to the room to reduce the decay time. In a small empty room with plastered concrete walls the decay time can easily be in the range of 1.5 ~ 2.5 seconds with some frequencies (typically the modal ones) having even longer decay times.

Absorption should be used to bring down the average decay time to the required figure (say 0.3 ~ 0.6 seconds depending on function).

It is really worthwhile to investigate the use of diffusers (something I was discounting at the beginning) and a couple of tuned absorbers for the offending modes that lie in the 40 ~ 80Hz range where porous absorbers can't really be as effective unless they start to occupy part of the room. I am considering a 2D diffuser for the back of the room and a combined cloud with absorption in the front and a skyline diffuser in the back.

I don't pretend to be an expert on the matter and I would welcome the more experienced to comment on my points.
Nothing you said here is "wrong", BUT if you use FRK on the fronts of the broad band bass traps that will reflect some of the highs but help absorb a bit more low end.

Glenn
Old 8th May 2009
  #9


Remember, too, that drywall on studs with insulation in the wall is already a membrane absorber. There is probably a way to tune this effect.



-tINY

Old 9th May 2009
  #10
Gear Maniac
 

Quote:
Originally Posted by tINY View Post

Remember, too, that drywall on studs with insulation in the wall is already a membrane absorber. There is probably a way to tune this effect.

-tINY
Cutting slats on the wall before mounting a broadband absorber at a distance?
Old 11th May 2009
  #11


That would be a slat resonator absorber... It may well work, but you just lost any hope of good insulation if an exterior wall is involved.



-tINY

Old 11th May 2009
  #12
Gear Maniac
 

Quote:
Originally Posted by tINY View Post

That would be a slat resonator absorber... It may well work, but you just lost any hope of good insulation if an exterior wall is involved.



-tINY
Yeah, there is that, too...
Old 12th May 2009
  #13
Gear Head
 

Thanks for the help guys!

Going to make heavier ones for the corners behind the monitors and lighter ones for the top half of the room where the walls meet the cieling and the cloud. Purely for hanging reasons

And yes i know not to cover everything, when I said a 'room full of traps' it was just a phrase!

I'll be sure to post photo's

Thanks again

thumbsup
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump