not really in this case, b/c there are so many problems.
First off, the core issue really is a lack of clarity in the sound system. Power is sufficient, but under utilized by crappy paper cone speakers Porsche allowed Nokia and HAES to set them up with. Unfortunately, a lot of people start in the wrong area and add a new amp or H/U. Those, w/out changing speakers, will just get you louder crappy sound IMNHO. Anyhow, as one who has been thru this, here are my recommendations in order:
DASH - Easiest to change out. Get a good pair of 4" 4ohm coaxials that have an RMS of 2W+. Hack the custom bracket and mount your new ones. You'll laugh when you take out the OEMs. The paper cones in them are only a "slightly better" material (weight wise) than the stuff that comes out of a laser printer. This will get you nice mid/high clarity in the system. I used Infinity Reference but a lot of people use MBQs (some say they are a little 'bright' though).
REARS - you're already done here. But are they powered by the h/u? I suspect so as '02 only had a 4x40 amp. Unscrew the amp from firewall to see if P/O might have upgraded you to a 6x40 (doubtful). It will say clearly on the label. If not, then you have a couple of options:
- get a 2ch amp to piggyback and power only the rears (more work than really needed)
- swap in a 6x40W amp from a 996 (find on ebay or at a swap meet - just make sure you get one from a car w/ the same architecture - M490 or M680) easiest
- put in a whole new 6 ch amp to power it all
I found a used 6x40 on ebay for $75. Works great and looks OEM. Was easy to swap in - only had to wire up rears to it (pins 5/15 and 6/16 for your future reference)
DOORS - this one took some time for me (and others). Hopefully you can learn from our trial and errors [read mistakes]. First off, the amp has a filter built in which only allows low freq to go to the doors. The stock door speakers are 5.25" 2 Ohms in a custom 'tuned port'. In a nut shell, you'll never find a 5.25" speakers that will hit the lows you want (needing less than 80W power or so). I tried 3 different sets - 2 sounded worse than stock and the other was only "as good". So, if you really want to hear/feel some lows, save yourself time and scrap the tuned port completely. Just make custom baffles and mount some 6.5" or 6.75" in there (good news on this one for you later). You'll want a pair that has a freq response at/below 45Hz, impedence of 2 Ohm (to match OEM) and a sensitivity of 90 dB or higher. You'll still only get lows if using a HAES amp, but with a good quality speaker, you can just eliminate the crossover (since it's built into the amp) and only wire up the woofers. I chose Infinity Kappa 6.75"s here [finally] and they sound great. I'm not an audiophile, but do appreciate clean music. Here's a link to their specs.
http://www.crutchfield.com/S-qywZsgezyvi/cgi-bin/ProdView.asp?g=52100&tab=features_and_specs&i=1086527I#Tab
A very nice match to the system and accomplished all my goals. I used to keep the h/u set at +7 bass and loudness on. Since the swap, I actually now keep the loudness off and bass at +2 at most.
In short (not really at this point), I was amazed at the clarity the system has and the lows it now hits. I like the fact that everything looks absolutely stock, but sounds so much better.
Now for the good news, here are 2 great links for you to use which go into greater detail:
Upgrading the Boxsters Sound System w/out going broke (by Andy M from Renntech) - a nice comprehensive guide
http://boxster.wikia.com/images/b/b6/Boxster_speakers_update_article.pdf
A template to make custom door baffles use in conjuction w/ Andy M's guide above but easier to install - only uses the OEM holes (by some jerk named Burg Boxster)
http://boxster.wikia.com/images/b/bf/Door_Baffle_Template.pdf
I stoppped there b/c I like the system now. In total, each step/upgrade took about 2-3hrs time but there was a lot of trial and error in there.
Good luck and feel free to PM w/ any questions.