Yamaha DTXpress/DTXplorer/DTXtreme

Claudio Ortiz Said:
> When we listen to live acoustic music as in an orchestra
> or dixieland band all the sounds get to our ear in a
> certain order. The highs travel faster, the lows
> travel slower.

As I was doing some research today on Sonar Ranging systems, I came
across this description of how Sonar works from well known author John
Iovine (author of many books on microcontrollers, robotics and other neat
tech stuff. see his book on amazon
here:http://www.amazon.com/exec/obidos/ASIN/0071354794/ref%3Dnosim/robotbooks-20/103-2794261-5227019)
Here's the relevant passage:

-------------- CLIP ----------------
The velocity of sound through the air is about 1100 feet per second. The
exact speed of sound actually varies slightly with the temperature of the
air. As a rule of thumb, velocity changes by 1 foot per second per degree
Farenheit. Thus, at 32 degrees F, sound travles at a velocity of
approximately 1100 feet per second. at 70 degrees F, the speed of sound
is closer to 1140 feet per second.

The frequency of a sound has no effect on it's velocity. So, two sounds
with different frequencies will travel at the same speed through the same
media. However, the media (the material which a sound travels) does
effect the speed. For instance, sounds travels 4000 feet per second
through water.
------------ END CLIP --------------

This was in the opening section describing using Sonar range finders to
determine locations and distance to objects. It was important to
establish that frequency doesn't affect the speed since the sonar system
was using ultrasonic sound (49.4 khz) in the finished product yet the
experiments used clearly audible sound to excercise the system and
demonstrate the principles clearly. After construction the freq is raised
to above the threshhold of human hearing so it won't be contantly
"pinging" and annoying people as it takes readings....

So... I'm back to square one again. I *still* don't know if/what the
Aphex (or BBE) Aural Exciter/Sonic Maximizer does. :( If it *does* have
the ability to make electronic drums sound more like "real" drums I'd
like to know how...? :)

Vern

-- 
Vern Graner CNE/CNA/SSE     | "If the network is down, then you're
Senior Systems Engineer     | obviously incompetent so why are we
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vern@... www.txis.com  | is up, then we obviously don't need
Cell 507-7851 Desk 328-8947 | you, so why are we paying you?" VLG