My space is 39" wide and I can go 20" tall.

How deep do I need to make the box (and how long AND wide does my slot port need to be) to have a net volume of 4-4.5cuft and a daily tuning of 30-33hz?

Power will come from 2 sundown saz1500's strapped at 2ohm.

Thanks

If you make the exterior dimension 39wx20hx15d, with a port (interior) 3.5wx18.5hx34l (about 65sqin of port) you should end up with around 4.15ft^3. You should probably run the port length through a good calculator, but I believe that will get you right where you want to be (30-33hz).

Do you have a link to a "good calculator"...perhaps this is my problem.

I've been doing most of my planning around the RE box calc.

Not really, the one I normally use is often wrong by a few inches, but it's here:

http://www.carstereo.com/help/Articles.cfm?id=31

Again, I don't trust this 100%, so I'd just google it till you find one that seems right.