question about my wall setup (doing away with it) need to hear from wall guys

[TonTon]

I built a wall with (2) stereo integrity ht18v3 subs, this was going in my work van so i thought why not use the baffle as my partition that divides the storage area from the drivers cabin? so thats what i did. My wall is about 1 foot behind the front seats and by the time you lay the seat back it hits it perfectly.

To be quick about this, from about 10-40 hz it kills it, total wind machine and totally kills those lows but once it gets past 40 hz its no longer enjoyable and quite honestly sounds like a turd in my opinion. Plus with windows up and windows down is a HUGE difference. Ive basically put myself inside of a 4 th order with different tuning depending on window position lol. I dunno wtf i was thinking.

However, the goal was only to have them play up to 50hz in the first place, my midbass take over good enough from there but are strongest around 60hz. The subs just seem really thin from 40hz up but super fat at 40. Dunno if im making any sense? 

If i move the wall to the rear of the vehicle do you guys think this problem will improve? It will be a lot of work but i guess not too bad since i have not finished the wall yet after a test listen i stopped for now. im wondering if the sound wave from a 50 -60hz tone will have more time to form if they are located a lot further back and im sure "box" tuning will be better around 50-60hz by moving them back. (closer to their ideal 40 cubic ft .707 qtc)

Just looking for guys that have done both and know what im talking about here before i do the work, sure my spl is great but past 40 hz output sounds odd. They are infinite baffle to a point....running on just a baffle board (or 10) so they see about 124 cubic ft (rough measurements of the cabin behind the baffle)....ideal volume enclosure for these guys is about 40 cubic ft sealed for both so they are in between sealed and infinite baffle at this point.

Thanks

[TonTon]

nevermind, i realized im experiencing cancellation.

[Joe X]

If  so you can phase invert the signal to the subs, some amps have controls to do this directly.