Typically it is most economical to purchase a silencer from a reputable manufacturer rather than trying to re-invent the wheel in house. However, if you want a good overview of the theory behind the designs, I would recommend:
Noise and Vibration Control Engineering: Principles and Applications
Leo Beranek (Editor) I. L. Ver (Editor)
Format: Hardcover, 1st ed., 804pp.
ISBN: 0471617512
Publisher: Wiley, John & Sons, Incorporated
Pub. Date: January 1992
