i really dont think you can go wrong either way. I have (2) 12" type Rs in the rear of my hatch and they hit hard and sound clear enough for what i use them for. With regards to the type X's I am kinda curious to hear what they sound like. I looked at the specs online and the frequency response is 23-200 Hz as opposed to the type R's which has a response of 24Hz-2kHz. Alpine was looking for these subs to do one thing.... hit low