I installed an amplifier and two 12in subwoofers in my 2013 Kia Optima with infinity sound system but no nav. Right now I'm keeping the stock head unit and speakers because it sounds better than using a metra adapter with an aftermarket head unit in my opinion, until I can figure out a better solution. I tapped off of the stock subwoofer wiring for the loc and removed the stock subwoofer. Is that frequency being crossed over before it gets to my line output converter? If so is there a better place to install the line output converter for a more full range signal? I just worry that I am crossing it over twice and limiting the frequency range.