I'd go with the lower tune unless your gonna have issues with the port being too long for your chosen enclosure. The 1.5db likely won't be noticed and most bass boosts on amps center around there anyways so its a simple thing to EQ it in if you really want it there. The 30Hz tune will let you drop a little lower before you unload which will help with some music. I have Mark's 20" prototype and a pair of his 18's here that I've been meaning to get into enclosures but just haven't had the time. They look very well built (cheap terminals but you can't beat the price) for what you pay. I was thinking of getting some of his 15's as well. Let us know how it all turns out.

 

thanks gleepoy.
yeah i decided to just do the 30hz tune. tracking says it will be here tomorrow. i might just build a box this weekend if its not too cold in my buddys workshop (no heat)

20incher huh? wouldnt happen to have a pic of that would you?
that would be an interesting sight!

 

This is a pic of it next to a DEI SX12...



Its a pro sound driver...I have the specs for it somewhere. I bought it as something that would make an interesting project. Doubt its gonna go in a car but may fill the garage nicely with some decent sound while I work in there