tips on making it louder

Ok so i just got back from my local shop where i had my system metered. Im running an Arc Audio FD1200 thats powering a 15 inch TC Sounds TC-3000 in a 3.4 cu ft box tuned to 30hz. All this is being controlled by an Alpine CDA-9887 headunit. This setup hit 146.2 DBs with the mic in the kickpanel. What are some ways i can make this system reach as close to 150 db as possible.?

Change your tuning making it closer to the resonant frequency of the vehicle.  Probably more like 58Hz (a wild guess.)Support the12volt.com

yeah that was my first thought was to change the tuning frequency. Thanks. What kind of gain should i expect if i was to tune it to the frequency of the vehicle?

Depends.  I've seen as much as +6db simply due to tuning.Support the12volt.com

wow thats quite an increase. Im definantly going to have to do that. Would you suggest a circle port or slot port?

Doesn't matter, whatever fits the box.  And excessive noise from the port is not necessarily detrimental when you are trying to add more tenths of a db.  For SPL, experiment....a LOT.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

So i thinking a circle port so that i can remove it and tweak with the tuning of the box.

I recommend downloading modeling software like WinISD and determining the optimum enclosure and geometry before you cut any wood.Support the12volt.com

Ok. What graphs should i pay special attention too? And should i mess with the tuning frequncy and box size?