Car Stereos: Subwoofer box, sound accuracy, ported box

Question
I recently bought a pair of subs in a box. There are 2 V121D4 subs in a box with an interior volume of 3.09 cubic feet. The box i have is sealed, but from looking at forums and talking with friends a ported box would increase not only the volume of sound but also the quality. I've heard my friends alpine play in a sealed and ported box and ported sounds much much better. I understand that there are specific mechanics involved in porting a box, but i am not sure how to apply this to my size box and subs. Can you help me determine if porting my box would improve the sound or not? and if so what size port should i make?

Thank you very much for your help, and the specs on my 2 subs are on the link below!

(http://www.visonikcaraudio.com/product.jhtm?id=571&cid=9)

Answer
Hi Garrett,

Porting the box would result in more volume, but your quality and sound accuracy would suffer.

The short and untechnical response is: ported = loud, sealed = clean.  If you want SQ, you go sealed.

As for how/where to port the box, I can't reasonably answer that as there's a lot of work involved in finding an accurate port location and size.  Your best bet is to buy a prebuilt box, or find someone who builds boxes for a living to get their input on the best size and location of the port.

Justin