The phase plug is not attached to the cone in any way. When you remove the dust cap, you see a hole, that's the inside of the voice coil former. At the end of the hole, you see the back plate. The phase plug is glued to the back plate and should be clear of the voice coil. Some speakers do have a bullet shaped dust cap acting as a phase plug. This kind of phase plug is glued to the cone and its weight is figured in the driver design. But the wooden "light bulb" phase plug of tweaked lowther drivers is not glued to the cone. Hope this help a little