Resources 
Fixing the various weird problems that crop up in a audio signal path is frustrating because you often cannot see the cause of the problem. This power point seminar has audio files identifying different sounds and what their cause may be. The Methodology for troubleshooting is discussed as well and a discussion of the tools you need in the field that are helpful but won't break the bank.
Trouble-Shooting Audio Systems
Audio Gain - Getting It Right
When it comes to audio signals, Gain is King. This seminar covered the issued involved in gain structure and covers two methods for setting up a system for good gain structure and signal to noise ratio.
Setting Up DSP Processors
Most DSP processors do not get used the the maximum of their capabilities. This seminar cover the various functions used in DSP system for audio signal adjustments. It covers dynamics controls such as limiters, compressors, expanders; frequency content control such as equalization and tone control, and noise reduction.
