Need help specing a new box

Hi Guys,

Hope you are all well and i aslo hope that some one can assist me with working out the correct spec for a true SPL box. please note I will only be doing SPL with this box.

Ok so I have 18mm ply wood, 1 12inch subwoofer, 1 amplifier and 1 battery.

Here's what i'd like to do

Get a minimum of 151db's from this setup

Equipment

DD Z1a

NSB 170 12v

Targa TG301-DW

The sub specs are as follows and i could be wrong because this is taken directly from the site.

12" COMP SUBWOOFER - DUAL 1

SPECIFICATIONS Fs (free air resonance): 48.7 Hz SPL (efficiency, 1W/1M): 89 dB Nominal Inpedance: 1/2 Ω Qts (total speaker "Q"): 0.606 Qes (electrical "Q"): 0.732 Qms (mechanical "Q"): 3.517 Vas (equivalent compliance): 20.84 L Mounting Depth: 195 mm Mounting Hole Diameter: 300 mm RMS (Watts): 2 x 1500W RMS

My Vehicle

Opel Corsa Lite +

Resonant Frequency 54Hz

Current Box

Box Properties

Name:

Type: Vented Box w/ Active HP Filter

Shape: Pyramid, truncated

Vb = 101.9 liters

Fb = 53.99 Hz

Fill = none

No. of Vents = 1

Vent shape = round

Vent ends = two flared

Dv = 247.9 mm

Lv = 290 mm

I would like to go slot port, i would like to increase on my number and i have already done the Big 3, deadening, and alternator upgrade.

Your help will be more than appreciated

Thank you and enjoy.