This guy said he used some signal analyzer and the full range is definitely to the rears! What a PITA!
That guy is talking about speaker inputs to the subwoofer drivers, I am talking about the signal input to the door sub's amp. Tap into the signal input, that is full range and gives you a subwoofer worthy singal. The speaker level inputs the the rear speaker drivers is filtered, plain and simple.
I don't have the diagrams, but it was something like "AUD1" + amd -
I think there is a sticky thread where you can find the diagrams. If I have time later I'll find it again.
I'd probably still recommend unplugging the front subs.
Agreed, the door isn't a good place for suboofers acoustically or mechanically. Their close proximity tends to produce an over modulated muddled tone, and sooner or later doors with subs start rattling. Subs belong in the trunk.
I finally finished my box. I made it as tall and as shallow possible. Each side is 1.2 cubic feet. I didn't go all the way to the left because there is a step on the trunk floor. The box sits between the step and the trunk's side on the right. Now if my other speaker would finally get here.
I picked up one of these, with an Alpine 12" r playing off a Alpine mono sub amp with 300 watts, sounds great, tapped off the rear speakers and used a Weather pak connector at the sub box so I can pull it in and out (a little tricky) when I go to the track to save some weight. Color matched well and for the money and free shipping it's a bargain.