I ordered a 12 inch sony XS-L122P5S car subwoofer (due to money restrictions), which is an alternative to the model I had previously ordered but which I cancelled. Sony recommends a 0.82CF enclosure if using a port. I am guessing they recommend this small size because they are taking into account in-car gain. I'd like to know what sort ofvolume/port length (or box tuning frequency) is recommended for this sub (for in-home use), in accordance with its T/S paremeters which are as follows:

Power rating: 380Watts RMS
freq. responce: 18-2000Hz
Sensitivity: 89dB/W/m
Impédance (ohm) 4 (single voice coil)
d (mm) 250.0
d (inches) 9.8
Rdc (ohms) 3.3
Fs (Hz) 24.8
Qts 0.37
Qes 0.39
Qms 7.02
Vas (liters) 86.7
Vas (cubic meters) 3.06
Mms (g) 162.1
Lvc (mH) 1.1
Xmax (mm) 5.7
Xmax (inches) 0.2
BL (Tm) 14.1

If anyone could do this for me I would be hugely grateful. BTW I am planning on using a 4 inch diameter port.