As I recall they were 6 inch Infiniti Kappa speakers, but don't bother with full spectrum speakers in the doors. The problem is they are projecting sound at your ankles and nothing but low frequency makes it to your ears. That's why the Bose system has subwoofers in the doors, and they know what they are doing. I have Infinity Reference in the dash and they account for 90% of the sound which is quite good in the mid to upper range. The cabin noise is so loud top up or down, volume trumps fidelity anyway. You want to enjoy Bach's Preludium in E major? you're in the wrong car. Six inch speakers in the door are max, best to make those subs, higher range speakers in the dash and behind your head are the way to go for my money. I actually built and tested a sub for the front trunk (the thread is there somewhere) which was a total failure. Might have broken the hood latch if I left it in, but the sound was far louder outside the car than in. Best of luck!
james, thank you for your write up on installing the door speakers. By any chance do you know remember what size you put in there and how big do you think you can go?
Since you appear to have some experience replacing spark plugs/tubes. I have a question for you. I am planning on replacing the spark plugs/tubes soon on my 99 boxster. when i look on Pelicans website they have assembly grease for spark plug tubes for $47. is there a lower cost alternative? like vaseline, dish soap? is this stuff a lubricant or a sealer?
You know I'd prefer to keep posting ideas in the open on the forum. This is a hobby for me and I don't take it too seriously. If I did I wouldn't be so open about my ideas. I will let you know I have not fleshed out the oiling path from the high pressure side of the driven gear to an oiling hole in the gear. I was waiting for someone to jump on that as a flaw, but perhaps it's not a flaw. The assumption is that the hole has to pass through the high pressure side where it will steal a smidgen of oil each rotation.