![Film-Tech Cinema Systems](http://www.film-tech.com/images/masthead.jpg) |
|
Home
Products
Store
Forum
Warehouse
Contact Us
|
|
|
|
Author
|
Topic: Screens - Sound Transmission
|
Andrew Lee
Film Handler
![](http://www.film-tech.com/ubbmembers/1330.jpg)
Posts: 99
From: Oakville, Ontario, Canada
Registered: Jun 2002
|
posted 07-16-2003 08:14 AM
It has come to my attention lately that there is no set standard for the measurement of sound transmission (frequency fall-off) through screen materials. Currently, samples of screen material are placed in front of a boxed in horn, a microphone placed in front of the screen, and a frequency sweep of 20 - 20K Hz is then generated and recorded. The results are then graphed as a function of dB loss over frequency and compared to no screen material at all. These tests are completed by individual labs, and sometimes speaker manufacturers, but to my knowledge, never the same way.
Some aspects of these tests bother me as there are no known standards for: size of test sample, microphone placement, and screen to horn distance. These tests can be easily optimized to suit the marketing needs of the company or individual involved. I and a few others would like to investigate test set-ups and possible submit a proposal to SMPTE and others for application to become a future standard.
As most of you are the experts in the field, your input would be most valuable. I am especially interested in coming up with a speaker to screen distance or range for consideration. Is there a nominal distance? Is there a distance specified by speaker manufacturers? What's the closest and farthest distance you have seen in an installation? Thank you all in advance for your feedback.
| IP: Logged
|
|
|
|
|
|
|
All times are Central (GMT -6:00)
|
|
Powered by Infopop Corporation
UBB.classicTM
6.3.1.2
The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion
and agrees to release the authors from any and all liability.
|
|
|
|