Im driving:

1994 850 Sedan (stock)

My car has two of the 3" on the front dash, 2 4.25's in the front doors, 2 4.25's in the back doors, and 2 9x6's (volvo's version of an 8x6 ive heard) in teh back dash. One of my 3"'s is dead, and the two 9x6's are not working. It also has the factory amp installed, however i am unaware if it is working or not.

I dont want to pay an audio place hundreds of dollars just to tell me im fuxed and need new speakers. Any ideas or helpful hints on how i can test these things out?

Also, i get a TON of vibration from my door speakers, and im thinking it is comming from the cheap plastic holders for where the door handles are inset (volvo owners will know what im talking about).

So questions summarized:

How can i nix the vibrations that are NOT from my speakers, but from cruddy doors,

and,

How can i figure out about my amp being broken, and/or get new speakers (should i just get a cd deck, and new 9x6's, or should i keep my stock door speakers, and get a cd deck, and a 10 inch wuffer...)

Halp pleaze

Oh, and im from minnesota, metro area, so if any of you know any good shops that can do this type of crap for free, or are willing to do it for free/nominal price, id be more than willing to swoop around the city next weekend.

Thanks.