So I've got a 2006 Mazda 3 and I've decided to do some audio upgrades. I'm basically doing a complete overhaul; going to install an Alpine HU with the 50Wx4 power pack for powering some Type S or Type R speakers (6.5 comps in front and 6x8 coaxials in the back). For a sub, I've decided on a single 12" Type R.

I don't want to look like an Alpine fanboy but I guess I kind of am one. I had some 6.5" Type R's in my old car that I took out and made bookshelf speakers out of them. Did all the research and math for the enclosure, built them out of 3/4" MDF with bracing, walls lined with cotton for dampening, and a PVC pipe port -- they almost match up to my set of $800 Event ASP8 studio monitors SQ-wise (I do recording/audio production as a hobby), which was pretty surprising considering the total cost of the build was ~$200-250.

Anyways, I guess I have some experience in building -- but I'm also guessing that building a subwoofer box is kind of a whole other area. My main question is: Sealed or ported? I listen to all kinds of music, mainly rock but by a small margin over electronic and hip hop. I know that a sealed enclosure will be more accurate and tight-sounding while a ported enclosure will be louder but smoother. But by how much? I'm NOT looking to wake up my entire neighborhood or rattle the **** out of my car because music just becomes noise at that point. I'm just looking for good SQ at moderate/normal volumes but the ability to push it louder ~5% of the time. After all there is always a show-off-to-your-friends factor when getting subs.

Secondly, I have no idea what amp to get for this sub. Its RMS rating is 300-1000 watts, but I am totally confused by the whole over/underpowering the sub issue. It also has dual voice coils (either 2 or 4 ohm) which confuses me even more. I figure I should match it with a 1000W mono amp (seems a little overkill to me), but I'm no expert. I have an Autocraft Gold battery (640 CCA) if that matters.

Lastly, is there a point in going for the Type R if I'm not going to push it all the time? I'm on a tight-ish budget so saving $ is key. If I can get the same good SQ from a cheaper 12" (maybe even a 10"), throw me some suggestions.

Sorry for the long-*** first post but hopefully I can get some pointers. Thanks.