I've always just used manufacturer specs when I built my boxes but a few days ago I decided to try the Torres calc and some internet search for proper size/tune. I built it downfire into the spare tire area of a Scion xA with the port to the side. I did it like that because this is my sons car and I was thinking protect the sub and keep crap from falling into the port.
I went a little over my target of 1.75 cu/ft because I changed port size at the last moment and the box was already built. Also I didn't do the L port like it says but I did change the box back and forth many times to make sure the tuning was right with the straight port.
Well last night I threw it in to see how it sounded before I went any farther and I'm kinda disappointed. The deep low end bass is about what I expected but the higher bass(rock/metal music) is almost non-existent. I'm running it at about 600 rms. I couldn't really play with the x-overs and gains much last night but what I did do led me to think it's the box.
Other than running the L7(I know), where did I go wrong? Did the downfire side port kill it? Port area wrong size? Tune too low? Just to check it I ran Kickers suggested specs through the Torres and their boxes are tuned to 45-50 hz.