Do you know if the wiring diagram is the same between the EX and SX? As much as I've been enjoying the audio system in my SX. I do feel as it needs a little extra bass.
Also instead of adding an extra bass bin, would it be possible to just upgrade the subs that are already in the vehicle and put their on their own amp?
The EX and SX head unit is the same and I think the wires at the kick panel are identical. You can check by getting into the panel and using an old speaker or a removed door speaker to jumper into the clip. For example I used my fader to only play from my rear passenger side. Then I used an old speaker and 2 pins with some wire to make a soft of speaker tester. I pushed the pins into the clip so they would contact the wires I thought were the rear passenger side speaker. When the speaker played I knew i had the correct wires. You could also use a multi-meter. Anyway I am pretty sure they are the same between EX and SX for that harness.