So my buddy has a new Caliber with the premium 9 speaker Boston Acoustics sound system.

He's pretty happy with it but wants to know if he can hook up an Infinity Reference 10" instead of the factory 8".

Has anyone worked on this car before? Anyone know what impedance the factory sub is or how much power it sees?

He wan't to know if he can just disconnect the factory sub and create a wire extension to the 10" in a box and run it off of the factory amp.

Any advice? He doesn't want to install an amp and everything so its either this or nothing.

I haven't gotten in there yet to check the impedance on the factory sub myself.

 

a prebuilt bass box would probably be best in a situation like this... integrates the amp, speaker, and box all in one

 

the factory sub will be 2 ohm, and they make them very high effiecency, so they don't need as much power.
Replacing the sub will give you less volume, so you'll turn it up. Guess what happens next?
Distortion, from clipping, which will destroy any good sub. and then you'll wonder why it sounds like .
Buy an amp, and sub. Install it properly.
Be happy.

 

This is what I have said to him but he's convinced on trying it. I said the only way it might work is if the impedances of the two subs are the same.

 

Unfortunately it sounds like your buddy is an idiot. At this point I would walk away and leave them to trash their new car on their own.