Measuring Xmax

[Person2017]

While the coil overhang is about 1.6mm, the 70% Bl point is about 4mm.

Hi, thanks, so if my the 70% Bl point is about 3.6m, I don´t really know about the physical restraints of spider and surround. If they are too restraining while getting close to their limits(excursion vs restoring force nonlinear) , even with 70BL they might cause much THD

I didnt measure the physical max excursion(xmech??), but it seems not that much.
So if the BL is likely ok at 3.6 mm excursion, if I can measure the restoring force at that point and deem it as linear, the speaker likely seems ok to handle 3,6mm excursion without too much THD?

 

[Person2017]

Hi,
out of curiosity I measured force vs excursion of the woofer suspension. Just one way, and very "static" measurement, just put coins on the cone.

7 Newtons - 2mm excursion
15 Newtons - 3,5 mm
21 Newtons - 4.2 mm

Xmech is about 5.5 mm

I also made a graph as attachment

If my measurements are of any use, could I conclude that I will not have strong compression (due to the suspension) at the calculated 70%BL-xmax of 3,6mm? Looks kind of like progressive suspension?