the bigger boxes are louder because you are limited to 3kW and it is a bigger vehicle (52Hz)... Did you try a bigger and longer port?

 

SD power too!!

 

what impedance ??

 

That's an awesome result ! Doesn't the box move around ?

What's weird is that in other setups port changes worked in reverse compared to your setup.
In another car (same sub) going from 6" to 8" gained around 1dB.
In my Jeep, going from 8" to 10" gained 0.8dB, totaling 151.0 with a Z1 and an older BTL 12.


Surely a 10" aero will help. 0.8-1dB, a lot but the overall score would still be small.

Forgot to add that, dual .7, wired to .35, rising to about 1.2 ohms.

Now I wonder if the car just plain sucks..

 

I was still learning a lot at that point, and I found with tuning, when it's off the box would slide to the port side. When I have the port just the right length it wouldn't move at all. Cheap tuning trick I guess when you don't have a termlab.

 

i'll post a pic of a box later

 

this box did 151 flat on a pair of 10's and 3k clamped in a jeep grand cherokee.

two subs are firing forward, those are 4 inch ports. box was about 2.2 cubes total



same box did 153 on about 5k clammped in this same car.

 

Whats the frequency of your jeep?

 

it peaked at 52 hz

 

Now, just getting into theory a bit, with a higher frequency vehicle, you would make the box a little smaller?