Cone stiffness???

[SUB_URBAN 10+ year member]

again, i mispoke (typed?) by calling the thread cone stiffness...... it's more a concern about the stiffness of the cone's movement.......
and sub urban, there's a video on realm of excursion with the EXACT setup you're describing if you want to indulge your curiosity

//content.invisioncic.com/y282845/emoticons/greedy.gif.5a53e6246569d7ab79867170f3b06629.gif :greedy: //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif

 

[Thnking 10+ year member]

Making the surround stiff is simply a design choice.

It affects the resonance of the subwoofer, it affects the mechanical and electrical parameters (like damping and movement).

Usually someone designs a stiffer surround to lessen or control travel.