4 speaker setup is standard. It's 6 if you count the tweets.
Stereo depth - 7.5"
Front - 6.75" with tweeter
Rear - 6.75"
The speakers are actually 6.5's, but you need a 6.75" adapter.
There was also a SSL package that added a powered sub.
Sub - 8"
Mounting Depth - 4.25"