The ring radiator tweeter features several improvements from the version in the earlier LSi line. A slight reshaping of the tweeter’s bullet-shaped phase plug allows it to move even farther out of the baffle, while a redesigned diaphragm has made the tweeter even more efficient.
Advanced driver material
The original LSi speakers featured a light, stiff mineral-filled polypropylene cone that was “puffed up” with injected air to form a honeycomb-like structure. The new super cell aerated polypropylene uses larger “puffed cells” to create a cone material that’s thicker yet lighter than the original.
The oval shape helps them produce tight low-frequency music and movie sounds while maintaining a narrow cabinet width. Plus, each woofer has its own PowerPort? ? a unique Polk design that positions specially designed “cones” at the mouth of the bass ports to direct moving air to eliminate bass-stealing turbulence.