×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Acoustics

Acoustics

Acoustics

(OP)
When we take the following
1. sound transmission loss in dB ...does higher number mean higher loss
2. for loudness in sones GF when we measure value inside car does higher value of sones mean it is louder. also inside a vehicle we do we use sonesGF or sonesGD

RE: Acoustics

A higher transmission loss number means a higher loss.  A higher sone level is also a higher sound level or louder sound.

Sones GF is the loudness index measured in a free field and sones GD is measured in a diffuse field.

I am not familiar with car measurements.  I can only say that except for high frequency sound, the interior cannot be classified as free field or diffuse.  High frequency sound has a very small wavelength which could approximate a point source and be considered in a free field.  The same goes for a diffuse field.  However the frequencies would have to be 1000 Hertz or higher.

C. Hugh (www.Hatch.ca)

RE: Acoustics

The company I work for in Australia, use sonesGD for windnoise measurements in cars. There's about 1.5 sones difference between GF and GD.

There are a few point sources in windnoise eg the door mirrors and leaks, but once you have them sorted (which is a must) then you have line and area sources.

As to which you SHOULD use, well, ask your customer which he wants.

  

Cheers

Greg Locock

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

White Paper - PLM and ERP: Their Respective Roles in Modern Manufacturing
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each person’s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now
White Paper - Medical Device Design Control
Medical device product development is a highly integrated and regulated process. Implementation of a requirements tracking solution requires attention to a variety of nuanced topics. When presented with the task of tracking the many concept relationships in a project of this type, the initial software solution of choice tends to be a two-dimensional text systems. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close