sub sound output explanation

do you have the rear of the enclosure almost butt up against the back of the cab? you could be gettng cancellation issues and when you open the window/door it gives those waves somewhere to go besides the front wave of the subwoofer.

it sounds like what was going on in my old setup. i had my sub forward facing in a sealed enclosure, behind the fold down seat. sounded like ass until i opened the trunk to give the rear waves somewhere to go instead of being out of phase with the fronts from the reflection off the back of the trunk lid. moving it further back up against back of the trunk yeilded better results. since that wasnt what i wanted, i had to seal the front of the sub almost 90% from the trunk area to get what i wanted.

now i know what some of you might say that there are no rear waves when a sub is in n enclosure, but just through my experimentation with that setup led me to believe otherwise. i dont have any scientific backup from test equipment like alot of guys might have and just use my ears, but thats what i found out.

but, pretty much any vehicle is going to have louder bass from their subwoofer systems with any sort of window open or vent in the cabin area.