Today's Active Topics · FORUM INDEX · Search Forum · Who's Online? · FAQs/Help · Calendar

Main Forums >> DIY, Electronics, Studio Design & Acoustics
Previous thread Previous   Topics   Next thread Next   Threaded Mode Threaded  
        Print Thread

Pages: 1
Platypus9



Joined: 01/09/04
Posts: 122
Loc: Montreal, Canada
Which NRC at which frequency? (Building an Absorber) new
      #978270 - 26/03/12 06:13 PM
Edit post Edit   Reply to this post Reply   Reply to this post Quote  
I'm building some broadband absorbers, mostly to reduce early reflections. I have a room Node at 125Hz. It seems like products that absorb well at 125Hz, don't at 4kHz, and vice verse. This is the product range that is available locally: http://www.imanson.com/files/manson/upload/documents/02_MIP_AK%20BOARD_10_ 10.pdf
Should I prioritize absorbing at 125Hz, or at the higher freqencies?


Post Extras: Print Post   Remind Me!   Notify Moderator     Back to top
Martin WalkerModerator
Watcher Of The Skies


Joined: 28/02/01
Posts: 16393
Loc: Cornwall, UK
Re: Which NRC at which frequency? (Building an Absorber) [Re: Platypus9]
      #978397 - 27/03/12 11:30 AM
Edit post Edit   Reply to this post Reply   Reply to this post Quote  
Hi Platypus9!

If you want a broadband absorber then go for 100mm 48kg/m3 - if you take a look at its acoustic performance in that PDF link of yours it’s good across the board:

125 = .95
250 = 1.11
500 = 1.17
1k = 1.07
2k = 1.07
4k = 1.06

I think you’ve been looking at the foil-backed versions, which reflect back higher frequencies


Martin

--------------------
YewTreeMagic


Post Extras: Print Post   Remind Me!   Notify Moderator     Back to top
Platypus9



Joined: 01/09/04
Posts: 122
Loc: Montreal, Canada
Re: Which NRC at which frequency? (Building an Absorber) new [Re: Martin Walker]
      #978573 - 27/03/12 08:09 PM
Edit post Edit   Reply to this post Reply   Reply to this post Quote  
Thanks Martin. The supplier isn't able to get the plain 102mm stuff, so I'll get the plain 51mm and double it up, and hopefully I'll get the same NRC you quoted. I haven't worked with rigid fiberglass before, I'm not sure if a thin gap between the two layers is significant acoustically.


Post Extras: Print Post   Remind Me!   Notify Moderator     Back to top
Martin WalkerModerator
Watcher Of The Skies


Joined: 28/02/01
Posts: 16393
Loc: Cornwall, UK
Re: Which NRC at which frequency? (Building an Absorber) new [Re: Platypus9]
      #979774 - 02/04/12 04:23 PM
Edit post Edit   Reply to this post Reply   Reply to this post Quote  
No, you'll be fine with two layers pushed together for a greater composite thickness - as long as the air can get in (i.e. no foil layer in the middle) it should measure exactly the same as one sheet of the larger thickness


Martin

--------------------
YewTreeMagic


Post Extras: Print Post   Remind Me!   Notify Moderator     Back to top
Pages: 1

Previous thread Previous   Topics   Next thread Next   Reply to this post Reply to thread   Threaded Mode Threaded  
Rate this thread

Jump to

Extra Information
0 registered and 83 anonymous users are browsing this forum.

Moderator:  David Etheridge, James Perrett, zenguitar, Martin Walker, Forum Admin, Hugh Robjohns, Zukan, Frank Eleveld, Will Betts,   		Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled 		Rating:
Thread views: 1599

 

Home | Search | News | Current Issue | Tablet Mag | Articles | Forum | Subscribe | Shop | Readers Ads

Advertise | Information | Digital Editions | Privacy Policy | Support

June 2013
On sale now at main newsagents and bookstores (or buy direct from the
SOS Web Shop)
SOS current Print Magazine: click here for FULL Contents list
Click image for June 2013
Other recent issues:
DAW Tips from SOS
100s of great articles!
Cubase
Digital Performer
Live
Logic
Pro Tools
Reaper
Reason
Sonar
 

Email: Contact SOS

Telephone: +44 (0)1954 789888

Fax: +44 (0)1954 789895

Registered Office: Media House, Trafalgar Way, Bar Hill, Cambridge, CB23 8SQ, United Kingdom.

Sound On Sound Ltd is registered in England and Wales.

Company number: 3015516 VAT number: GB 638 5307 26

         

All contents copyright © SOS Publications Group and/or its licensors, 1985-2013. All rights reserved.
The contents of this article are subject to worldwide copyright protection and reproduction in whole or part, whether mechanical or electronic, is expressly forbidden without the prior written consent of the Publishers. Great care has been taken to ensure accuracy in the preparation of this article but neither Sound On Sound Limited nor the publishers can be held responsible for its contents. The views expressed are those of the contributors and not necessarily those of the publishers.

Web site designed & maintained by PB Associates | SOS | Relative Media