On Fri, 02 Sep 2005 01:16:55 GMT, "BillyBob"
wrote:


"LRod" wrote in message
.. .

As someone else pointed out, it's logarithmic, so your calculation
isn't quite. An easier way to understand it is that 10 dB is actually
10x, and the next 10 is a power of 10 (10^2=100). So what you have is
20dB is x100, the next 3dB doubles that to 200, and the 1dB left over
is a fraction of x2, so around 220 or so is the decimal equivalent of
24dB.

It's those stray dB between 9 and 10 that messes your calculation up.
9 dB is 8x, but 10 dB is 10x.

Now you had to go and analyze it and make me go check the math. Darn I hate
it when that happens. You had it right until that very last 1 db. A 1db
increase is a 1.26x increase. (200 * 1.26) = 251+

The formula for db is 10 * log (p1/p2). Its not a pure log function.
There's a 10x factor in there. There's a very cool webpage on this with
actual sound files at http://www.phys.unsw.edu.au/~jw/dB.html.

Thanks. 1 dB always did give me trouble. Leave it to someone named
BillyBob to square me away. Would have been perfect if you were named
Bubba.


--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997