Sub help, 8" subs in doors Options

[d3ath2009]

i have a 97 with the 4 speaker system and i want to replace the door speakers with some 8" subs, but i dont wanna buy any then find out they won't fit..... what's the max depth?? do i need free air subs??

[quick_5hifter]

I have a 3-way component Hertz setup. 0,8 inch tweeter, 3 inch midrange, 8 inch kickwoofer and 3-way passive crossover. It sounds really great, even if my doors are not sealed yet.
I had a little trouble installing the 8 inch kickwoofers, I had to cut the plastic to make room for a larger magnet and also add a 5 mm thick MDF ring, but it was a 2-hour operation and it wasn't that difficult.
I don't recommend installing subwoofers inside the doors unless you only need SPL; it would be like having only a subwoofer in the trunk and 2 tweeters in the front, there will be no voice in your music. You need a little kickbass and midtones to call it "music".

8 inch kickwoofers are also available from Ground Zero, DLS, Focal, Alpine etc. (I think Focal's are larger than 8 inch, I'm not sure...).