Audio Systems: Jaguar X-type Door Speaker Malfunction, jaguar x type, fibre optic cable

Question
I have a 2002 Jag X-type.  It had the factory premium (Alpine)stereo w/sub woofer and CD changer.  I do not have navigation.  I also can't find an amp in the trunk.  My fibre optic cable goes from the head unit to the CD changer.  Here is my problem.  My 6.5" speakers quit working (suddenly and all at once).  I unpluggd them and hooked up the tweeters in their place and the tweeters worked.  I hooked the 6.5" up to the tweeter lead and they did not work.  What could be the problem?  Could all four speakers have blown at once?  Please help!

Mark

Answer
if what you are typing  here is correct all the speakers are blow
take one speaker and go to radio shack use one of their ohms tester and read the ohms  1.5 to 3.00 ohms they are still ok
this speakers are 2 ohms   

if  they read zero they are blown   

it is posibble that the  amplifier is bad and it send current to the
speakers

the fiberoptic amplifier  works on 8 or 10 channels

good luck