Alpine HU w/Mach 460....what sub/amp/enclosure to get???

I've got an Alpine 7894 HU (single CD w/3 4V pre-outs) rated at 60x4 watts. My stock 460 is still in tact along with the stock amps. The CD sound is way better than before (I had cassette only) and the mids and highs sound cleaner and much louder. However the low end is questionable and lacks a solid presence. I simply no longer have the bass I did with the stock HU, but I'm not going back to that. The Alpine HU gives me the flexibility I need and should provide even better mids once I can alter the rear speakers to stay off the lows and leave that to the subs.

Since I am using the stock amps, I don't think my HU is powering anything (not sure as I'm not very knowledgeable in audio). I want a sub that can produce a good full bottom end for classical/jazz/pop (not interested in rap, hip hop, or entertaining my neighborhood). Quality is a concern, but price is just as important. I've seen the Bazooka stuff which makes sense, but maybe not for my needs. Crutchfield had a good description of the different types of subs and I think I'm looking for a sealed sub due to the type of sound it will product. Here's the excerpt:

If you prefer a cleaner sound (more suitable to jazz, classical, pop, etc.), subwoofers in sealed boxes tend to produce tighter bass — allowing you to hear more of the sharp, punchy edges that define each note.

If you like rap, reggae, alternative, or heavy metal, you'll probably want a looser, boomier sound. You'll get this type of sound from a subwoofer loaded in a ported or bandpass enclosure. For an inside look at how boxes produce different sound, click here.

Will the all-in-one systems do OK or should I put the parts together seperately? I'm wondering if I can just buy an enclosure, a decent sub, and just connect it to my HU. You know the Mach460 setup and the space it takes, so whatever I get must take up less then half the trunk.

Any ideas? (I've tried to research audio websites, but it's left me more confused. Many questions I have simply aren't answered online.)

Thanks.

Thanks. I'll do some research on that to see what the costs are.

I did do a search on the Alpine 7894 HU and I found where a couple people had problems with getting much low sound, even with the HU's sub control turned up to max and the sub's volume turned to max. Someone else mentioned that the gain was too low. Do you think my HU will be fine or is Apline known for not giving good lows? (granted, the forums I found this on weren't nearly as reputable as others).

Thanks.

I think I want a lower watt rating, like a rating of 50-200. What about the Hz rating? Is a rating of 32-200hz good, or should it be wider?

For example, Alpine has a speaker with this rating: 50-200W RMS total power range • 30-1,000 Hz frequency response. (I know you didn't suggest Alpine specifically, but there subs have quite a wide Hz range when most others have smaller. I want to hear decent bass at lower volumes and I don't want a gap between what the sub's upper rang and the mid's lower range.

I like the looks and specs of the Phoenix Gold Ti10D (500w RMS). The Alpine amp suggested above can be had for $135 easily brand new, but it is only 200w RMS. Should I consider a 300-400 watt mono sub amp? If so, what are some good amp brands?

I will go by some stereo shops and listen to some different combos when I get some time.

Building my own sub box definitely is an option. Just need to find the correct specs once I've settled on a setup.

I believe the Phoenix Gold Ti10D is the dual 4 ohm version and it looks pretty nice. I like the Alpine unit on paper, plus it should work well with my HU, also Alpine.

Thanks about the info on the 2 ohm setup. That will definitely make a difference.