If you run the factory Bose speakers off of an aftermarket head unit you are risking melt down. It will work, it will play for a while BUT you are damaging the head unit. The Bose speakers are .5 Ohm, that 1/2 Ohm. What that means is that they will drive your new, aftermarket head unit harder than it cares to be driven.--Kinda like the way we all drive Z's, but the Z's are built for it--It will play and play loudly for a while but eventually it will destroy the amplifier inside the aftermarket head unit. The only way to use the factory Bose speakers is with the Bose amps and either the factory Bose head unit or with an aftermarket head unit and an adaptor. The adaptors make it possible to run the miss matched Ohm loads. Aftermarket head units are made to run 4 Ohm speaks. Home stereos standardly use 8 Ohm speaks.