The 4 aeros are 6inches internal diameter each. That is 28in^2 of moving mass per port. The enclosure is 9.8ft^3 of internal volume after all displacements. This gives us a ratio of 11.4in^2 of moving mass per ft^3 of internal volume. This is a very ideal ratio for a daily driver system. It gives a great balance between port gain, and musicality. It will still get plenty loud, and the subs will also play further below port without unloading.
The majority of box builders will usually build at 14in^2 per cube as a minimum, then upwards of 18-20in^2 to get more output for the meter. Once you do the math, its actually not as much port area as it seems.
Just seemed like too much for me since im used to building with a lot of cone area and we used 4 of these for 8 15" setup and 5 of these for 12 15'' setup.
Stripper pole looks nice Box looks solid too nice job