Hey Narwol. I recently purchased a 2017 Accord EX-L V-6 and it has the 'premium' 360 watt, 7 speaker audio system in it. The factory installed speakers are total crap, paper cones and plastic frames, plus I'd bet the one you have are equipped with tiny magnets as well. I just replaced my rear deck and door speakers with Rockford Fosgate Punch series 6.5" speakers and the system sounds much better, and I will be replacing the factory subwoofer this weekend with a Polk Audio 8" DB840. Having said all that, I would highly recommend that you upgrade the 4 speakers you have and you should actually do that before you even consider a subwoofer (in my opinion). The factory speakers are full range speakers so you might want to consider replacing them with 2-way speakers, or 2-way's in the rear deck and a component system in the front doors. If you wanted to do this in the front door, you can buy the accord sail cover that is designed for a tweeter and replace your current solid sail covers. So this should help you get started towards making a decision about the speakers. Check YouTube for videos on how to remove the door panels and rear deck (which requires the removal of the seats). You will also need speaker mounting brackets as the factory speakers are manufactured directly to the bracket, so spend the $12 and buy the replacement brackets (American International HSB524). There is much more to the audio question though and it all depends how far you want to take things. For one, your factory amp is only a 4 channel amp, so you have no way to just add a sub to your system without adding a replacement/separate amp or maybe even a powered sub. Hope this helps!