From most builds and info I've seen, a sealed cabinet usually limits the bass extention, but leads to a smoother rolloff.
Hypothetically speaking, lets say the LGK driver in a ported enclosure can play down to 90hz at -3dB then dropping off 6dB per octave.
A sealed enclosure will limit it's -3dB range to say ~100hz but will roll off at 3db per octave.
