I am planning on using the pn4.520 in my 2012 Street Glide, with Polk MM651 speakers in the fairing. I am keeping the stock head unit for now. I am not running any other speakers at this time, but want to the four channel amp for future expansion. Should I bridge the amp to run the fronts at this time or just run the fronts off the front channels. If I bridge the amp, how do I do the wiring?

 

You can not bridge the amp with the polks. the polks are 2.7 ohm and the amp has to have a 4ohm load when bridged.

Just hook the fronts to the front channel and leave the rear blank for now. It is plenty.

 

Just wire it to the front channels on the amp. Just did my system and wow it's loud.