Speaker, in this case, woofer size is measured screw-to-screw of the speakers mounting ring, which we obviously don't see with these speakers as it is mounted from inside, so while, looking at your photo and considering some distortion of the camera, it looks like E7 XT has something like 5.5", which is just a dome, but if we measured screw-to-screw of the mounting frame it would be probably 6.5" size.
Still, there is no shame in creating a support ticket at
https://my.presonus.com/support/ and asking their support team to validate it. It is true, though, E7 XT's woofer seems tiny, but that is because the cabinet is almost of the E8 XT's size (E8 is a couple of millimeters wider and deeper) and while we don't have 8" monster woofer, we still have that mighty waveguide.
