i built a ported dual chamber box to hold 4 pearless 6.5 mids ( my doors are awfull - but thats another story for later ) so there is left and right - fiberglassed the bottom to match the hump on the tranny tunnel. used pvc pipe to port each side not shure of the tuning but might be in the 40s ( might try cutting an inch of each port and see if that brings tuning up a little.
hate if you like - its kinda ugly and in the way looking - but it suits me
and shakes the rear view mirror on bass / mid bass on just the mids
and the port just happens to give my gas pedal foot some nice air flow !!