I had added 2 10" kicker and they are powered by Alpine PDX m12. Right now the whole system sounded pretty good but I want to upgrade the mid's and high's. Can I add a 4 channels Alpine PDX and JBM MS8 to the existing Bose speakers or is it better off just to replace all the speakers? I know this question had been answered on this forum before but I want to see if anyone has done this without replacing the speakers. Also, for anyone already replaced their components, what should I look for as far as the dimension of the speakers and tweeters to get an exact fit? Thank you all!!!!!!!!!!!!

 

You can add a 4 channel amp to the existing speakers. You will have to do a few things:
1) Find an amp that can drive 2 ohm speakers for EACH output. I think this will be pretty tough, but I could be wrong. (i.e. Good Luck)
2) Disconnect the input wires to the stock amp for the 4 speakers you want to push, and put them into the 4 ch amp inputs.
3) Disconnect the output wires from the stock amp to the same 4 speakers and plug those into the 4 ch amp outputs.
4) Power the amp, and you're good to go.

A few notes on this approach.
-Bose stock speakers are usually trash, sometimes made of cardboard. I don't know the quality of ours, but I bet it isn't great. Almost anything aftermarket will be better quality.
-You will have 5 other speakers not being pushed by an amp. At the very least get a 5 channel and push your center speaker along with the 4 door speakers. The problem with this is your other 4-5 speakers will still be getting stock power while the 4-5 speakers on the amp will be getting more power. Ideally, you would have ALL 9 (leave out the sub) speakers being pushed by an amp.

Thus, your very best option is to get a 4 channel and a 5 channel amp, use the existing wires to make the connections bypassing the stock amp, and swap out all of your speakers. Sorry, I don't know the size of our speakers.