I also liked the idea of presets but it turned out that it's one thing to do them for linear movement (click-lock presets on headbands, for example) but another thing to do it for rotational movement.
There would have to be a sort of a wheel with holes at circumference that allow the spring/ball to click in...Since the usable range of setting is between 10 and 45 degrees, where we would want about 6-7 presets, like every 5 degrees or so, the circumference would have to be large enough to place 2mm holes (or notches) every 5 degrees...Basically, the size weight and complexity of that mechanism left us with a preference for a lightweight friction-bearing that allows fine-tuning, which we use now.
Nitinol is great with it's superelasticity, where it is needed, but we actually don't really want that in our spring because we'd loose the adjustment capability.
I still haven't done a proper video that shows how to make the adjustments / fitting (sorry about that), but basically, it's all about bending the spring to desired directions enough so it stays deformed just the way you need it, setting the forces and angles to the values you feel most comfortable with.
Superelasicity would oppose those actions and all of the spring shape, upper and lower clamping forces and angles could not be adjusted as the thing would always want to retain it's factory set shape.
We can't use the same methods as circumaural pads headphones that use gimbal or fork/pivot mechanism to automatically adjust themselves to the shape of the skull, so it was either this or a bunch of joints with set-screws and that would be too confusing...
There are lots of pros and cons for every idea or a feature, but we think we got them all balanced the best way.