I have a 2009 WRX base model sedan. I don't mind not having the navigation system, sunroof, etc., but the base stereo is pretty awful. I'm not an audiophile, but I instantly disliked the base stereo as soon as I turned it on. I recently got a $50 Best Buy gift certificate, so that gave me reason enough to replace the stock speakers. I wasn't looking to spend a ton of money (there's more important things to buy, like an AccessPORT), so here's what I worked out for $100 total. It sounds a lot better--good enough that I don't plan on making any other upgrades to the audio system.
There are four speakers in the WRX sedan: two in the front doors, two in the back doors. All of them are 6 1/2". I bought two new pairs of 6 1/2" Pioneer TS-G1642R speakers for $50/pair. The Pioneers weighed more than twice as much as the stock speakers (22 oz. vs 10 oz.). At least the stock speakers don't have paper cones, but they're still pretty crappy. Here's a comparison of the two:
Anyway, here's a rundown of what I did. Click on the pictures for larger ones. Keep in mind this is for a sedan. I'm not sure how this compares to the hatch.
First, remove the door trim. Removal is similar for all of the doors. There is a screw behind the door handle and one in the hand hold, shown here:
Next, remove the window/lock control panel (gray/silver part of the arm rest on my car). I was able to do this with my hands to avoid marring the door panel. Just grab near the lower rear portion of the panel and pull out while gently pulling up. Once this is off, remove the two remaining screws holding the panel onto the door, shown here:
There is also a small triangular plastic piece above the door panel that needs to be removed; it pulls off pretty easily (sorry, no pics). Once that is off, there are only plastic snaps holding the door panel on. Get your fingers behind the door panel and pull gently. Once all the snaps are out, lift up on the door panel and pull it outward. This will give you sufficient access to the speaker to remove it. You could disconnect the door/window controls and the door handle, but I didn't find this to be necessary. Just make sure you support the panel to prevent the cables and wires from pulling the plastic liner away from the inside of the door while you remove the speaker. Here's what you'll see:
Disconnect the plug from the speaker. Remove the three screws holding the speaker onto the door. Repeat all of the above for the three remaining speakers.
Now that you have all of the speakers out, you'll need to remove the stock speakers from the spacers. This procedure is similar for the front and rear speakers. Pictures of the front speakers are shown. First, use a small saw to cut the plastic spokes connecting the magnet to the spacer. Cut them as close to the spacer as possible, as shown here:
Next, cut the outer rim of the speaker surround as close to the spacer as possible. Then use an Exacto knife to help remove the outer foam gasket from the spacer. Once the foam gasket is separated from the spacer, it's pretty easy to pull off. Try to make sure it comes off in one piece.
The two wires leading to the speaker should be the only thing left holding the speaker and spacer together. Desolder these and this is what you get:
Now you need to modify the spacer to accept the new speaker. This is done differently for the front and rear speakers. Here's what I did for the front:
Place the new speaker into the spacer. Mark and drill holes for mounting it. My new speakers came with pushnut retaining clips, shown below, which probably come standard with most new speakers. I cut slots for these directly beneath each of the holes I just drilled in the spacer. Once the slot is drilled, slide the pushnut retaining clip onto the spacer. Next, place the speaker onto the spacer and secure it with some screws.
Pushnut retaining clip:
Pushnut in slot with screw:
Place the foam gasket (removed earlier) around the new speaker, and this is what you get:
Just solder wires from the speaker connector to the speaker and you're finished with the front speakers.