Im crossposting this from a different forum, because i want as many opinions as possible before I make a decision.
Ok, sonotube is cut, drivers are tested and sitting in the corner. about to cut my end caps tomorrow.
A final decision on tune/port length before I cut the ports.
Here is a winISD plot at 650 watts with a 17, 15, and 13.2hz tune. All three plots have a high pass filter applied to limit excursion down below the tuning point, so it may seem like they're dropping off quickly. In actuality this is a more realworld since I will be applying a filter anyways for safety and headroom.
So, which plot do you like the most ? Don't pay too much attention to spl as I will be running 2 of these with 650 watts to each. Extension is more important to me than max spl. Excursion is safe, just a hair over xmax, and port velocities are ok, a max of around 24m/sec on the 13hz tune.