yea it will be just a daily beater. Playin lots of low low bass. i see AQ recommends 40hz tuning but alot of the music i listen to is lower than 40hz, i think thats why my idmax smoked because i played below tuning too much. So i was thinking of going down to 28hz tuning but i dont want to sacrafice too much output.
I like the HD's at 35Hz in around 4.5cubes. Will hit low, but still have good output.
You could build the box with a little extra port area, and then extend the port if you don't like the higher tune. I started at 38Hz, but it was a little boomy on some music, so I added 3" to drop it to 35...