In Reply to: Aftermarket sub w/ stock amp - what ohm rating? posted by Kevin on August 01, 2001 at 14:00:23:
When you wire speakers in a series, you double the ohm rating of the speaker (aka, if you wire 2 4ohm speakers in a sieries, they together, produce a 8ohm rating)
When you wire speakers in parrallel, you split the ohm rating (aka, if you wire 2 4ohm speakers in parrallel, they together, produce a 2ohm rating)
It is very important to understand this, wire it correctly, and to now what the ohm rating expectation is on the amp being used. If you wire to 2 car speaker in parrallel and connect them to a home receiver, you will most likely overheat the receiver. It is possible to blow amps by using incorrect ohm loads.
Hope this helps....