I have a JBL GT4-10 Sub, i'm looking in to making my own box for it, to go in the boot of the car.

i've been round and got various programs that work out box dimensions. but i've not a clue...the dimensions it gives me for the spec of the sub are strange, ie. the front face of the box, where the sub would be mounted, i have less than 20mm either side...

my maths skills are practically non-existant so i can't work it out my self, well won't because i'll mess it up =\

so if anybody knows what they're doing when working out dimensions....i'd be very grateful

Specifications

RMS Power Handling :250W

Peak Power :1000W

Frequency Response :28Hz - 500Hz

Sensitivity :90dB

Impedance :4 Ohms

Voice-Coil Diameter :50mm

Cut-Out Diameter :232mm

Mounting Depth :150mm

Overall Diameter :258mm

Vas :36.10L

Qts :0.42

Fs :29.6Hz

Qes :0.45

Qms :6.45

Sealed Enclosure (vol) :21L

Sealed Enclosure (vol) :50L

^^ eh? sealed enclosure two different numbers for the same thing =\

any help on this would be fantastic...