This website has a nice laymans tutorial on the physics of sound waves:

Sound Waves

Very interesting page.
Tanx for sharing.

SOUND ENGINEERS SURVIVAL GUIDE

Main Frequency Regions

http://heartsoffireproductions.com/studio/...sound_guide.htm

Sound Frequencies to cure your ills

http://www.lunarsight.com/freq.htm

The Speed Of Sound

Interesting page about the speed of sound, density of air, acoustic impedance vs. temperature.

http://www.sengpielaudio.com/calculator-speedsound.htm

From SoundOnSound Magazine:

A glossary of sound technical terms.

http://www.soundonsound.com/information/Glossary.php

There's Life Above 20 Kilohertz!

From Caltech Music Lab:

http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

THE INVENTOR OF STEREO

A site dealing with the life and works of prolific British inventor, Alan Blumlein. His work has remained in obscurity until recently due to Churchill, who ordered that all his work be treated as secret after Blumlein and his team lost their lives during an experimental flight on a Halifax bomber which crashed while -*test*-('")ing the H2S radar system.

http://www.doramusic.com/index_blumlein.htm

Alvaro,

The link you just posted is truly fantastic. Thank you.

Tanx amigo.
I have that link for a quite some time now, but today i was organizing my "million dollar" links, and stumble to it.
What's amazes me is that i never saw in any audio forum - and i know a few...- not a single word about this great man.
..but, this is Sound-Thinking!