The Use of Tuned Porting in Modern Stringed Instruments

Tuned porting has been a crical aspect of audio system speaker enclosure design for many years. Only recently, has the idea of porting beyond what is provided by the sound holes, been considered in the design of musical instruments, paricularly stringed instruments, plucked as well as bowed.

With stringed musical instruments, porting refers to strategically placing extra holes (in addition to the sound holes) to work magic with the apertue to air volume ratio of the instrument. Two of these holes are clearly evident in the photo of an Adventurer IId Travel Violin by Don Rickert Lutherie. Porting aften involves intenal air tunnels which are, through much experimentation, tuned to control the in-flow and out-flow of air in the sound box when the instrument is played, resulting in a much more powerful sound output than previously thought possible. This is analogous to the incredible big sound achieved by tiny speaker systems by Bose and other innovators in the audio equipment field.

Much of the emphasis on musical instrument porting is on achieving a better balance between the weaker percieved acoustic response of the lower strings with the higher-pitched strings. This endeavor is often summarized as "increasing the bass response."