Hello,
I have the non-bose, standard Delta radio (80 Watt system).

I want to put in a subwoofer into my car, I am looking to spend less than $250 for just the subwoofer, I have an ALPINE 70Watt (mono) amp to use for power.

I listen to Hard Metel, RAP and Rock-n-roll and Jazz.

I LOVE BASS, big booming BASS.

ANy suggestions?

Eric

Hello Eric,
I just went through the process of trying various setups for adding bass to my 99 A4. I ended up with one 10" Blaupunkt Pro Series Sub and a 170w Pioneer amp. I had a rather large and heavy box in the car with two 12" Rockford subs and the same amp. My opinion is that two 12" subs are to much for this car. And weight was my major concern. I would definitely go with two subs vs. one for the times when you want it loud. For all other types of music, one sub will work. Another option would be a bandpass enclosure. Also, if you are familiar with Audio Control equipment, they have what is called an Epicenter Bass Restoration device similar to a crossover. ($159)
This could help with smaller subs. The JL Audio stealth box is also nice but to expensive in my opinion.
Sorry for the length, but hope this helps.