The Podcomplex DAW Guide has just been updated, and now includes a section on the physics of audio. This is an introduction to the basic science of sound, and will be expanding to deal with the topic in more detail over the coming weeks.
Covered in this section are definitions and explanations of wavelength, frequency and amplitude, as well as illustrations of the behavior and properties of sound waves. The decibel scale of loudness measurement is introduced, as are interference phenomena such as constructive/destructive interference (cancellation/reinforcement) and beat generation. Although such knowledge is not essential for most musicians, it is important for recording and mastering engineers to have a firm grasp of what they are dealing with; the more they know about how sound behaves, the better they can manipulate it to achieve a desired effect. As such, anyone who wants to set up microphones for recording, intends mixing or mastering audio in their home studio, or is just plain curious, should take the time to learn as much as they can about the properties of sound. So why not start right here?