After putting in the polk component speakers, the highs are so much better b/c now they are at ear level but the mids and obviously lows are pretty lackluster with the stock headunit. I think there's only one guys in this forum that had the alpine power pack professionally installed. So far the consensus has been that we should just get a regular amp...but I still like the idea of the power pack and that it just sits in the dash.
You can't overcome physics. You could put tons of power on that sub, but it will NEVER...EVER....reach anything near respectable dB's below say 40-50hz. And damn sure won't do it with low distortion. And damn sure not off 50 watts (probably using less than 10 most of the time). Lets not forget it's on a flimsy, metal deck also! With a free-air or IB subwoofer configuration, one thing will always prevail....cone area. You NEED cone area if you're pursing this. Unless someone is going to reinforce the rear deck, deaden it, cut out larger holes and hang 2-3 12's, 13's or some 15's from it....I would just scrap the idea all together if the factory setup isn't doing it for you.
There are tons of amps on DIYMA right now for sale that are below $130, right at $130 or just above $130 that are on another level from that little thing. I will say that mainstream car audio companies have fully achieved what they set out to achieve. They've got most believing that more power is better. That the jump from a 400rms amp to a 550rms amp is worth another $150 and that you'll notice the difference easily. That you NEED a 1000 watt amp to push a single 12. All of that....is disturbing.
If you are looking to thicken up your bass I would go to crutchfield.com and do one of the two options:
* Look at the 2-Channel amps that can be Bridged to power a single subwoofer. There are some pretty cost effective solutions there. Use this to power an aftermarket sub (The kicker 8" seems to get good reviews in IB installations and I know many of the Chrysler LX guys have used them in the stock rear deck cutout to thicken up the stock stereo). If you are keeping all of your other speakers stock you are not going to need more than 100-150 watts.
* Look at the self-powered subwoofer packages that could be mounted under the reardeck firing up thru the stock hole keeping the stock look.
It takes power to make bass, and that Power pack is not going to do it. Plus you need a low pass filter and I dont think the powerpack has it.