[BruceH]

I kept my amp and replaced all of my speakers with Pioneer and then later replaced my HU with Pioneer. I am very happy with the results. Replacing the door speakers with 6.5" speakers definitely improved the bass response. I do get some mids and highs through the door speakers with the stock amp although they are not as clear as the dash and rear speakers.

http://986forum.com/forums/general-discussions/49796-found-6-5-speakers-fit-door-without-mods.html

Amazon.com : Pioneer TS-D1002R 4 In. 2-Way Speaker with 110 Watts Max. Power : Vehicle Speakers : Car Electronics
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Amazon.com : Pioneer TS-A1675R 6-1/2" 3-Way TS Series Coaxial Car Speakers : Vehicle Surface Mounted Speakers : Car Electronics