making vented subwoofer enclosure?

mgnt232 wrote: so if I use the recommended specs as above, will my sub sound horrible? or will it just sound better if i go through all the math and trial and error? thanks-

It depends on what sound you are looking for. If you just want a loud system then that enclosure design would give you that. 38Hz is a pretty high tuning frequency which is usually meant for getting loud. If you are looking for any type of sound quality at all you will want to have a lower tuning frequency. If you want a "better" enclosure then I recommend either downloading WinISD and figuring out how to use that or seeing if someone will model up an enclosure for you. WinISD or a similar program will allow you to design an enclosure to fit the sound you are looking for. It takes some knowledge to use and design a proper enclosure but it is very useful. There is still a lot that goes into building a good enclosure. By reading the stickies on this forum and asking questions there is no reason why you can't build a good enclosure. You just need some know-how and some basic tools. That should give you an enclosure that will sound pretty good.

mgnt232 wrote: I am using Lanzar heritage 15" HRWDC15, i had them in a bandpass box, but it was just bought off ebay, before i knew about the whole tuning thing, and i was always wondering y there was so much noise from the ports as the air passed through them, and thats y i want to build my own to stop that noise but still give me the edge that a vent does. thanks for any one who can help me!=]

There is no benefit of a vent over a round port as far as an audible difference. The subs will sound the same with a round port as they do with a slot port (assumming all else equal). Slot ports are often convenient or more pratical in most situations but they have to advantage in sound. It really depends on your application what is going to be better to use.