Does anyone here know much about tline subs? I just bought a new test subject from goodwill.
it is actually pretty damned good for what it is, but SQ is lacking

The driver is 5 inches in diameter from center of surround to center of surround. 5in/2=2.5in so, 2.5(2.5)3.14= 19.625. So the port area is going to be 19.6" square.
Length is 1130/ 30 = 37.66 ft long Full wave length. Divide this by 4 for 1/4 wave wich equals= 9.41ft long.
Is this right? 9.41ft seems ginormous! 19" square seems tiny. Is my math right?
If I make the box 6"wide inside then the port is only 3.2" across, so maybe that won't be so bad. If I did the math right
Any suggestions?
thanks HD