When the box is closer to the hatch then the port is wide the hatch then acts like another port, thus, tuning the box to whatever the trucks resonant frequency is. That's what I was thinking, but it didn't change my score. My peak went up from 36 to 37hz, that was the only change. Move it back and listen to it, then slide it away from the hatch and listen to it. Sounds MUCH better I promise. Oh I agree with you there. It moves more air too, IMO even if the meter does say no.