And to address the OP many of the speakers that Bose produces for automotive applications are of lower impedance (1/2 -2 ohm) than what you would “normally” find in aftermarket speakers (4-8 ohms). This works to thier advantage when Bose creates an entire sound system coupled with an EQed amplifier and allows them to create low wattage systems with sound pressure levels that are on par with similar high wattage aftermarket systems. Having smaller/effiencant low wattage systems is attractive to auto manufactuers. Also, because of the low impedance of some Bose speakers (generally bass) an aftermarket amp would not drive them correctly, leading people to think that they are crap when they try to use them elsewhere. This is further complicated by the fact that Bose refuses to list any specs so that you could properly match them and this drive audiophiles nuts because they love to throw around specs in order to impress/confuse people.