Need helps gaining some db!

[Jeffdachef 5,000+ posts]

Like shave 6 inches off on one side putting me at 16 cubes.
Shouldn't I be up to the upper 150s though with this equipment? Put the box aside. I thought that these woofers on this power are fully capable in 150s. I just want to know what I'm aiming for.

If you shave some inches off the sides you will change the box tuning and the port area needed for that box. With too much port area, it'll be peaky and with a smaller box and same port size you'll be tuned higher. So in a way it might be advantageous on the meter but it'll sound wierd with all those peaks in all the wrong places.