how do you connect 2 300w car amps to put out 600w to one 10" sub?



You buy two subs. Be sure they are of the same brand or they will not sound good at all. Be sure the amps are also the same. Or go and get a 5 channel and some crossovers.
Sandisk1duo7 years ago
you can't

Unless your sub has 2 voice coils
If you have enough data  about your amps, you wire them in a "bridge" configuration.

Steve