In certain embodiments, a tower lifting system comprises a primary lifting system and a secondary lifting system. The coil component includes a core; at least one bobbin coupled to the core and having a coil wound therearound; and a base having the core seated therein and including an external connection terminal, wherein one side of the core is seated in the bobbin and the other side thereof is exposed to the outside of the base. The diaphragm assembly and the backplate assembly constitute a variable capacitor responsive to sound pressure level changes coupled through an acoustic port. The step of associating the filling material with the primary continuous layer comprises at least one sub-step of positioning the filling material according to a predetermined geometric arrangement on the primary continuous layer .