Dekay, it's good to hear that you and others are considering the benefits of single driver systems. I'm sure you know that you needn't "get on my good side" :-) in order for me to try to give you any assistance I can. My main reason for doing this type of post is to help others see that there are some different ways of doing things in audio than the usual run-of-the-mill. And to help them benefit from my experiences, good or bad. Apparently, there are some who would ridicule me for my views. But, they are far in the minority and I prefer to concentrate on my projects and helping any members that may be interested. If I can be of any help to any of you, please email me, and I will give close attention to your needs, and give whatever help I can. I do not claim to be the ultimate authority on these subjects, but I am working with these concepts and products, so I do have some good working knowledge of them. As for the 40Hz cutoff for the Voigt Pipes, I may not even quite get down to 40Hz, but I will try to get what I can without sacrificing any midrange quality. I would love to get to 20Hz, but it's not possible with this design. My efforts are to get the most from the least and typically that will entail some trade-offs, in this case, the deepest bass is REDUCED but not eliminated. While some may consider this "sacrilege", I feel that all designs are limited and one has to pick their weak points as in all engineering and design work. My preference is to accept lower output in the 20Hz-40Hz region, in order to get the advantages offerred in the rest of the spectrum by single driver designs. There are more exotic cabinets available that will give 32Hz cutoff for the same drivers. Maybe, down the road, I will build them. I feel honored that Albert, in particular, is interested in my efforts in this area, because of my great respect for his knowledge, experience, and integrity. At the end of this road, we will know more than when we started, and that, in itself, is worthy of the effort.