First of all, I know not to expect a large amount of bass capability from 6x9 speakers, but my lack of bass is so astronomical it's sickening. I have 4 stock sized Infinity References in the stock locations driven by a 200 watt 4 channel Audiobahn amp. My sister has two Infinity Kappa's in her Honda Civic that are driven right off the stock head unit and they sound like a pair of 15" sub woofers compared to mine. It feels as if I'm running a high pass filter on all my speakers, but I'm not. Only the fronts.

I'm not ready for a sub, but I would at least like something out of these. What is my problem?

 

Reverse the polarity on one of the 6x9s and see what happens.

 

Yeah, it sounds stupid, but check your phasing. With two cheapo 6x9s in the stock sail panels and an aftermarket head unit in my brother's 83, there is more than enough bass for casual listening.