The RT25i, one model up from the least expensive Polk speaker, is a two-way bookshelf satellite sporting a 1" trilaminate polymer-dome tweeter and a 5?" mineral-loaded polymer/composite-cone woofer, both drivers shielded for home-theater applications. The woofer was designed using Polk's Dynamic Balance technology, which employs heterodyning laser-interferometer analysis to minimize resonances. The rear-ported enclosure uses Polk's unique Power Port technology, which consists of a cone at the mouth of the port and space between the rear of the cabinet and the port cone to maximize efficiency while minimizing port noise, or "chuffing." The cabinet also uses two small ports on the front of the speaker, these tuned to resonate at the same frequency as the cabinet's internal depth resonance. This is intended to minimize coloration resulting from the cabinet's air-space resonance.
Speakers show heavy sighns of wear back of one has broken bracket. They have been tested and all drivers work