I have a bmw 02 330xi with the upgrade Harmon and Kardon system. How many watts are these speakers pumping?

I need to know this because i want to add a subwoofer into it but do not want to blow out the speakers or not have enough power. I need help with all of this really then recommendations would be nice for subwoofers that would work.

Thanks alot!I have a bmw 02 330xi with the upgrade Harmon and Kardon system. How many watts are these speakers pumping?Upgrade system from manufacturers are not that powerful, usually a total power of 300 to 500 watts total power for the whole system. If you want to ugrade and put amps in, use JBL speakers (probobly already installed as part of Harmon Kardon (Harmon Kardon makes head unit and is the parent company of JBL and Infinity). I have used JBL power amps and speaker for my car and it is clear sound with deep bass also made by JBL. I don't know the size of the speakers used on your car. Call crutchfield and ask them for replacement speaker and they will be able to determine the size in your car.