Actually, most of the pipe organs I've seen (...don't ask) have used a cap technique. For example. you take a 16 foot pipe and cap the top to create the equivalent of the a 32 foot pipe (one octave lower). The air has to travel up then down, so travels twice the distance.

In fact, while they do exist, I've personally never seen a "real" (sometimes called "full length") 64' Diaphone's. They have always been capped 32 foot pipes.

......not sure how I relate any of this information to my car mind you....

Later!

Dang