Tune your mids/highs first, then subwoofer after. Without any equipment, I’ve always done it this way: turn the headunit to about 3/4 volume(ex; mine goes to 45, I tuned at 35 and occasionally listen at 40 on certain songs) then while playing a variety of songs adjust the gain and HPF. I turn my HPF all the way up and then adjust it through the headunit(usually 100-120hz). If you have any signs of distortion or clipping, back the gain down on the amp until it goes away. I like to listen to a couple different genres of music while doing this to make sure I won’t have any issues and can normally get it tuned within a few songs. Don’t try to get all the bass possible out of the Polks. That’s where your subwoofer will come in and let me tell you, our little TJ’s make the biggest difference in sound quality with a little bass. You’ll be very happy with the sound once you have a sub installed.