New here and need help with port size. I just installed (2) PIONEER TS-SW3002S4 12" 1,500-Watt Shallow-Mount Subwoofers in a 32Wx13Hx11D box. Using these subs allows me to keep some trunk space. I used a calculator to figure the size and it told me 2" and 5 1/2" long. To me this seems kinda...