Q. What is the effect of the soundport?

 

A. The effect of a sound port is proportional to the size of the sound hole. The effect on an oval hole can be dramatic, as the net amount of escaping air is almost doubled. This doesn’t seem to compromise the instruments forward projection, the overall volume usually increases.

The effect on a D hole is subtler as the air flow is already maximized by the original design.

In both cases there is noticeable better monitoring for the player, again more pronounced with an oval hole, where there is noticeable air stream displacement from the side port.

On an oval hole model a sound port also allows many of the trapped overtones and lower frequencies to escape, adding sustain and a wide range of color. This effect is harder to detect on a D hole.