Sub Box Dimensions Or Guide

[.:Bullen:.]

Hi guys looking to get rid of the lame bose subwoofer with a better one with more punch.

 

Im open to ideas & suggestions on 10" or 12" but was just wondering if anyone had any dimensions & sizes etc for custom sub boxes under the rear strut or perhaps inplace of the bose sub if thats even possible ?

 

I am owed a favour by a woodwork company so they said if I can get the sizes they will knock it up for me.

 

Any help appreciated cheers