well i built 2 seperate boxs for my l7s each at about 4.81 after sub displacement or along the lines of that i dont feel like doing the math right now lol.

i had a slot pot in it that was around 3.5in. by 15in. once again not being exact.
turns out it was like tuned completely wrong so i just took that out and put in 2 4in. pvc ports for each box tuned to 30hz.

it sounds fine and loud as hell to me but im thinking if i go bigger on the ports maybe it will get a lil louder. suggestions?