Wayne Parham Messages: 18787 Registered: January 2001
Illuminati (33rd Degree)
You could make the tube long enough that it formed a 1/4 wave pipe tuned for bass. That would use the standing wave as a tuning mechanism. Another thing that comes to mind is to make the tube smaller, so that it was really just a volume to make a sealed or vented sub. In this way, the shape isn't as important as the volume.