Re: hello everyone i have a few questions about enclosures.
For material, MDF is the best thing to use and if you're conscious of weight and have money to blow, Birch plywood is lighter and very dense too.
Aero (flared) ports are more efficient than straight edged ports whether they're round or not.
Thirty to 40Hz is quite the spread but regardless, there are a number of online calculators that will help you with tuning. Just query Google for "port calculator".
I have no idea what a bypass port is but if you could explain it a bit better, perhaps I can help. As for the "best" type of enclosure, that depends on your goals. However, the most efficient enclosure you can build is a ¼ wave transmission line.
Enclosures in which you cannot see the sub are called bandpass and they are not designed for appearance. They are designed to be very efficient in a specific (usually narrow) passband of frequencies. The cons to them are that they perform poorly outside their passband.
Owner, Audio Anarchy, LLC
2915 Youree Drive, Shreveport, LA