"Q5. MY BOSE amp died on the back of one of my speakers, can i use the power from my headunit?
A5. NO, NO,NO. Bose runs their speakers at 1ohm. Aftermarket headunits run their channels at 4ohms unless otherwise stated. 99% of the time it will be 4ohms.
Q6. Can i replace a BOSE speaker with a different brand speaker and connect it to the BOSE amp?
A6. NO, NO, NO. Once again, the speaker runs on 1ohm, most, 99% of aftermarket speakers run on 4ohms. You will ruin the amp or your speaker, whichever comes first."
taken from the link in post #21.