Major improvement
I just sealed and increased the dampening these boxes. Oh my how much better they sound.
I can definitely say this confirms a sealed approach is the right direction.
Even with the sealed the response changes little in terms of proper crossover according to my ears. I suggest a 100hz crossover for either. Sealed is clearly better. Wow. Alex I suggest you plug the ports at least and add more stuffing to see for yourself. Put them as close to the wall as possible IMO. It seems to really help the low end.