i came across this over on diyma and wanted to share it. tried it with a mockup in my truck with no eq or ta, then auto eq/ta on my deck and both sounded pretty good.
You can keep your kick panels as compact as possible if you vent them into the A pillars instead of the carpet and they will work better as well.
I also like to reshape metal a bit it needed to get the midbasses as far back and wide as possible.
I would just line the back of them with something thin like I use, scraps of ensolite, it does the just just fine, I will send you some pieces if you wish.
All you have to do is look behind the trim panel and find the factory hole into the pillar and open up the back of the kick you build to match, then stuff a small amount of dacron into the hole.
I learned this from the gurus at ID and it works very well indeed.
Here is the guide I wrote from their advice, been using it for years now.
1) Put your front seats where you intend to either drive the car or where you will have them if you plan to compete, this is very very important. I am talking about fore and aft, height, seat back tilt angle. If not competing then where you will drive the car at and the passenger side the same.
If you are competing in car audio comps, then all the way back and low but even with the passenger side for height, lean the seats back a bit but not real far to make them uncomfortable.
2) Sit in your seat as you would driving or listening as per above, make sure you are correctly placed, if you tend to drive leaning way forward like some do, you should adjust how you sit, better for your posture anyway, lol, lean back in the seat
(here is an additional hint, almost all will do better if the seats are lowered, leaned back quite a bit, etc. but in my Tacoma I had to raise the seats, go figure
3) Have somebody you trust to do this correctly, critically important. Roll the windows up, have them look very very carefully at where the entrance to your eardrum is on your window side ear, left ear, mark it on the window or on the pillar with a small spot of tape.
4) Move to the other front seat and do the same except of course on the right ear this time.
5) Ok to get out of the car now Measure 5" forward and 1.5" down from the spot marked for your ear entrance points on each side of the car, should be two marks on the car now, one for your ears and one forward and down as above.
6) Build some temp baffles for the speakers or the ones you will use, what I do. Have the tweeters mounted very low and to the door side of the baffle, the woofers go furthest forward and low as well.
7) Aim the woofers(midbasses) exactly at the forward and down spot on the glass you marked.
This is the sweet spot, instead of fighting the glass reflections you are using them to your advantage. The right speaker will reflect off the left glass into your left ear and help equalize the sound you hear from both speakers, seems odd but it works, exceptionally well. I beat a prior world champ twice in two months, two seperate installs in my truck and two totally seperate comp installs in his truck and a customers truck using these methods of alignment.
8)Take a kitchen towel and put it behind the baffels can cover the back of the speakers, then do some serious listening tests to see if you need to align them differently but this should be pretty darn accurate.
9) Be very carefull when glassing the kicks as the glass can pull them out of alignment when drying as tends to shrink so mount the baffles very well before glassing.
10) Wire the midbass on the passenger out of phase with the drivers side midbass, you may lose some midbass output but the sub can help make up for that quite well when tuned properly, better yet to have some midbasses in the doors. Try all the phasing setups you can, sometimes the drivers side is best, sometimes but not often, both in phase works)
For those not building kicks here is a simple install plan that works quite well, has been used alot in competion cars.
1) use the door locations for the midbasses, both in phase.
2) tweeters in the A pillars firing directly at each other, as wide apart as possible, both at the same exact height and about 2" above the highest point on the dash. Wire both tweeters out of phase(pos and neg wires reversed but this may have to be reconsideded depending on the midbass wiring, take your timem and try them all! Make sure to try many different aim points as well.
3) Use a dash mat, fugly but they work.
In fact, a dash mat will improve just about any install ever done, including kick panels, have one in my truck, been there for years"