Maximum power in WinISD

HI all,

So Im currently in the process of designing a subwoofer using 2x DSA215 PR's and 1x SB23MFCL-4 although almost finished I had one last question:

Is the maximum power in WinISD only looking at Xmax without any filter?
Since due to exceeding Xmax I will have to use a High Pass filter at 26 Hz but turning this on and off does not reflect in a change of the maximum power graph. With the filter Im way below Xmax (both for the PRs as the driver) when the signal input is on 150 Watt.

An externally hosted image should be here but it was not working when we last tested it.