On 10/18/01 18:03, "Kerry Thompson" <[EMAIL PROTECTED]> wrote:
> >> Could anyone provide some advice on how to to calculate decibels from a >> sample value for a peak meter...or perhaps just point me in the right >> direction? > > It looks like Dennis Flood uses the same formulas I use. His: > ( log( inputValue / maxInputValue ) )*10 > > I usually write it > > 20 log (P actual / P ref) > 10 > > where P is the sound pressure. For multiple, uncorrelated sources, P actual > becomes the square root of the sum of the squares of P for the different > sources. In other words, for practical purposes, > > 20 log (sqrt(P ^2 + P ^2 + ... P ^2) > 10 1 2 n > > which is the same as > > 10 log (P actual / P ref) > 10 > > I hope the formatting comes out ok--I had to put subscripts on the line > below since html e-mail is frowned upon (there is an email still smoldering > in my system, somewhere, from an html post I did 3 years ago). > > > Cordially, > > Kerry Thompson > > > [To remove yourself from this list, or to change to digest mode, go to > http://www.penworks.com/LUJ/lingo-l.cgi To post messages to the list, > email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]) > Lingo-L is for learning and helping with programming Lingo. Thanks!] > > Ah Kerry... Thank-you!..much appreciated. This is perfect. Formatting (or lack thereof) is a little funny but I think I have just enough meager knowledge to put it all together. <grin> Again thanks! Best Regards, Joe [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/LUJ/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]) Lingo-L is for learning and helping with programming Lingo. Thanks!]
