I read in !emc-pstc that Ken Javor <ken.ja...@emccompliance.com> wrote (in <bb4987fa.372a%ken.ja...@emccompliance.com>) about 'pulse modulation in reverb chambers' on Sun, 27 Jul 2003:
> As long as >those delays are much shorter than 1 us (path difference much less than >300 meters), the original modulation is received. Not really. If a reflection arrives with a delay of 10 us, the received pulse is 1.01 us long. Some 'rays' suffer multiple reflections, which increases the delay considerably, and the reflections in a reverberation chamber must be low-loss. How much stretching can you accept? >But if delays are too >long, then the pulse smears. Yes. How long is 'too long' for you? If you can find someone who has ray-tracing software for either electromagnetic **or acoustic** applications, you can run some simulations. Just remember if you use acoustic to treat seconds as microseconds. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
