FONT=Century Gothic]Easiest that I know of is what I did in my Pro5 and am going to be moving into my 3s-4dr...
I got an Infinity Basslink from my local 'big box' electronics store. It's an excellent sub if you want to add depth and quality to your sound, and generate a little thump without being too strong. If you're looking to rumble the neighborhood, forget it, you'd need at least 2 of these babies, and they are close to about $450 with installation per unit. There are even two mounting formats: Horizontal and Vertical, depending on your preference. (lol2)
The best part about the Basslink for me (being that the factory headunit meets all my needs) is that you can install it to the factory headunit without any LOC, as it allows both RCA inputs and line-level inputs. Check it out, it's a very good piece of equipment. (drive)
In my Pro5, I had it mounted in the horizontal fashion to the back of the rear seat (so it was actually vertical) - this worked well, but robbed me of space for oversized cargo when the seat was down. My challenge now is mounting the baby in my 4-door. I test-fitted it, and found that the best place seems to be on the left, as close to the side as possible, as close to the seatback as possible.
But... 3 minor little issues: (1) the side panel needs to be notched out at the bottom to accommodate the feet on the mounting brackets, (2) the rearmost bracket will enroach on the plastic spare tire cover, requiring it to be notched out about 2-3" and (3) the slope of the well where the spare sits is going to mean that the threads of the mounting screw will be exposed about 1/2" before actually starting into the steel. I can handle 1 and 2, but not too fond of 3. Now I do plan on dropping a dab of black waterproof roofing caulk into each screwhole before screwing in the screws so that it seals around the screws completely, but I'm just not sure about that one that's going to go into the spare well. I thought about maybe buying some sort of plastic collar and cutting it to length to cover the threads, which is what I may do...or I may just skip that screw altogether and just let the other three hold the Basslink in place; it should be plenty sturdy.
Suggestions? (group)
All in all, the Basslink is a very good all-in-one unit with the amp and sub conveniently packaged. They also have a Basslink X which is in a clear plastic housing and a Basslink T which is a much larger multi-speaker unit.[/FONT]
Badger Biker said:
As far as I know, you will need an amp to power the sub.
You can get the signal from the headunit with a LOC.
Cost varies wildly. I would highly suggest checking out the Car Audio forums that are on this website, and other places like sounddomain.com.
However, a lot of the time with car audio, you get what you pay for.