I'm planning on building a front firing sub enclosure in the trunk of a 2nd gen TL. My previous install in a differnt car had front firing subs behind fold-down rear seats which sounded 100x better than having them play rearward in a sealed trunk. My question is:
1. How do I remove the center pass-thru door in the rear seat?
2. Will I have any problems with the center pass-thru acting like a port?

 

check this out before you decide http://installer.com/tech/aiming.html

 

i have my single jl 12w6v2 firing thru the ski pass thru.. the only thing i would say is make sure you build a ported enclosure because it sounds a 100x better than a foward firing sub in a sealed enclosure.. if you would like i can send you a couple of pictures of my install..

 

The sub enclosure I plan on building would span the entire width and height of the rear seatback and as far forward as possible, flush with the rear seat sealing off the interior from the trunk, thus avoiding any reflections towards the rear of the trunk. This way, I find the bass sounding very tight and not "boomy" if it were firing into the trunk, this also reduces trunk rattle considerably. If I were to port the enclosure, would I port it back into the trunk or maybe up thru the rear deck thru the oem sub hole?

 

Would this possibly behave somewhere between a sealed box and a bandpass box? I'm no audio engineer, but its fun to think about.

Say you got a perfect seal against the rear seat (which is going to be hard...possible tho) so it only pressurizes the cabin space and none in the trunk. By playing thru a "port" (skiport) it seems like you'd be creating a design similar to a bandbass box. You have 2 volumes of air...the box (enc 1) and the air space in front of the subs and behind the seat (enc 2). Granted, the skiport doesn't have a really long "length" like a bandpass port would, but maybe it would affect the sound...? If so you might have a peak in a certain frequency range as opposed to a relatively flat curve like a sealed enclosure playing freely in the cabin.

Maybe it would sound close to a sealed box...maybe boomy in a certain range like bandpass...or maybe just sound poor. I don't know...just thinking out loud.

I do like your idea of wanting to eliminate trunk rattle...I did quite a bit to avoid it (in a different way tho...subs on the rear deck). Trunk rattle is horrible.

You should ask that guy Eddie Runner on the site that Rusky posted.