Anyone know speaker specs?
 

I was looking to replace the speakers in my 99 Boxster. It is the stock stero with only the door panel and dash speakers. Does anyone know the dimesions so i can order aftermarket speakers to replace them? Anyone have any preferences as to brands?

1" Tweeters (dash)
4" Drivers (dash)
5.25" Woofers (door), but a 6.5 will fit with a little encouragement

not many people will recommend just replacing the speakers as the output from the factory head unit/amp is so weak that you will barely notice the improvement in speaker quality. in my opinion, there are two better options:

1 - just add some rear fill with the factory rear speaker kit and use the 996 amp. prices for this setup vary depending on where you source the speaker kit and amp, but you can usually find both on ebay for cheap. there have been many write ups on this install.

2 - you can buy a decent 3-way component speaker system and a 2-channel amplifier that will work with the factory head unit. the JL Audio XR653-CS 3-way component system uses a 1" tweeter, 4" mid driver and a 6.5" midbass driver with a passive crosser. this system handles 70W RMS. the DLS CA22 2-channel amplifier has a typical output of 60W RMS and accepts line level inputs, so you don't need to swap out your factory head unit.

option 1 just adds volume, whereas option 2 improves overall sound quality, but costs around twice as much - $580 bucks from infinitecaraudio.com. and if you've never installed an audio system, you may want to consider paying professional installers to help with option 2 because you'd have to run power/ground wires for the amp and the 6.5 woofers in the door would require a little modification and some sound deadening.