subs sound alot better with window down?

Im not satisfied with my subs? I am not an expert so, im coming to you'all 4 sum help. Ive got one ten inch audiobahn sub that is 1800 watts dual voice coil sub.900 rms . 450 each voice coil i guess. well its hooked up to a sony explode 1200 watt amp and bridged. the voice coils say  something bout being hooked up or are 4 ohms or something? im confused now sorry but i just wired them bridged with the positve split so it goes to each positve on each voice coil and the same with the negative. well it sounds alright but the speaker sounds like it just bottoms out easy or sumthing. AND when i roll down all 4 windows it sounds ALOT LOUDER. THE SUb is in one ten inch box dual ported and its baffled to one port with like 6 inch ports or sumthing. IDK what to do. BUt what i wana know is why the windows down is it louder. and whats the best way to wire this sub? THANKS you guys are so good at answering ?'s with subs its unbelievable.   oh yeah the box is in the back seat of my car with the sub facing the front along with the ports.

Was the box designed for the sub?  Ported boxes require careful calculations to get the best performance out of the sub.  When you lower the windows you are altering the interior cabin space of the vehicle, and basically changing the "tune" of the box.  A better designed box may help you out.

You need to find out exactly which sub you have and which amp you have.  When we know the actual impedence of each sub instead of just a guess and we know the configuration of the amp (one channel, two channel, 1 ohm stable, 2 ohm stable, etc) we can advise how to wire everything up.

its a 2 channel amp sony exlode 1200 watts 500 watts bridged its a gtx2200 model.

the subs are audiobahn AW1006t 1800 watts dual voice coil. ten inch. each voice coil has 2 positves and 2 negatives. 900 rms.  Re 3.0 ohms  freq resp 22hz-500hz.   Then  the amp is 1200 watts max 500 watts Rms x 1 at 4 ohms. (4 ohms stable in bridged mode)   The subs have a dual 4 ohm voice coil setup.

If you have done this..... Kevin has the best answer!

Thanx, But the thing is i have only the one sub. not 2  .  unless im not understanding the total picture here?  but the connections on the sub have the 2 positives connections side by side. and  the negatives side by side.  and the same thing on the other side of the sub.

ok if this helps

the demensions.  Hole is 9 inches , lenght is 28 inches, height is 14 inches, depth is 14 inches, dual ported 3.5 inches flared. Baffled to one port. Made from 3/4 inch MDF.  So that amp isnt big enough? HMMM well let me talke to my girlfriend and see if we can get the amp.? i dont know why it sound like the sub bottoms out or is getting to much power. i wouldnt of even bought the sub if it wasnt going to pound but maybe the sub ant mounted in there tight enough idk? do u think that would do it? well thanks again. i appreciate it.

You very well may be bottoming out the sub. A subsonic filter is needed with a vented enclosure. The sub is mechanicaly unloaded under the tuning frequency. Set a subsonic crossover at or just below the FB(tuning frequency of the enclosure). Also you have 2 spots per sides for positive and neg but, this is for ease of installation. The 2 positives and negs you see in the picture below of your sub still only work one coil. So it really only has 1 pos and neg per side.