actually, bass waves or sine waves get louder especially lower freqs as it hits or bounces off. this phenomenon is called "transfer function". notice that in a front firing sub, towards the cabin. as you open the trunk and go farther from the car, the bass gets louder. it bounces of the front cabin and is released thru openind the tunk. if it was rear firing, it hits the trunk and as it bounces of it towards the cabin area it gets louder. this is why in most competitions, notice where the mic is put? it is in the front dash because this is the 'sweet' spot of the car. its not because more air is pushed. notice how a miata's cabin with an 8 inch sub be louder than in a ford excursion? it is because of the transfer function and not because more air is being pushed. also, kung nahuhuli man yun 8 sa 12 of the same sub baka the sub was not meant to play fast, meaning its not as precise or the motor construction was made for a different application. ex 10 solobaric at 12 solobaric. pero pag 10inch w7 at 13w7 kahit anong beats pwede. this is one reason why when choosing a sub based on what type of music you listen to, it's best to check out its motor construction and the application is which is was designed for rather than thru the size of the woofer.