I just got an Alpine 12" Type-R sub, capable of handling 500 watts RMS. The amp (Alpine MRP-M500) should work well with it. I'm going with a ported box, but I'm confused with it. I read some of the sticky's but how do you tune the hz? Why do you do it? And how do you actually, and properly, build a ported enclosure? If someone could explain the significance of "tuning" things, it'd help a lot. And also, how to tune it.