Nice thread jack there hollywood.
OP to find what your box rise is, you need a clamp meter and a DMM.
it's pretty simple, really. hook the dmm up as ac voltage to the speaker leads, and clamp the clamp meter around ONE speaker wire (pick one, positive or negative, don't matter) and set it on amperage.
voltage X amperage = wattage
voltage / amperage = resistance < that's your rise
(i may have that backwards though, check amperage / voltage just in case)
If you want LESS rise, a bigger box often helps, as well as things like port flares and SMOOTH resin.