The addition to the top of the Polk “Audio Monitor Series” line is the Model RTA 12C, a full-size, floor-standing 4-ohm speaker system embodying design concepts that have earned Polk speakers a reputation for quality and value. Polk uses a pair of small (5-1/2-inch) laminated-polymer cone drivers for the bass and much of the midrange. The drivers, which are identical, operate together up to 600 Hz; one then rolls off while the other is used up to 2,000 Hz. The two drivers are in a large enclosure with a “Vent” consisting of a 12-inch flat-diaphragm passive radiator. The purely acoustic crossover between the driven and passive radiators takes place at 60 Hz. The final design of the system, including its rather complex crossover networks, was done with the aid of a Fast Fourier Transform (FFT) computer program developed by Polk. The system supplied for test came with a curve showing a frequency response flat within ± 3 dB from 50 to 20,000 Hz, plus a virtually uniform phase-vs.-frequency characteristic.
The small woofer cones are located near the top of the wooden cabinet, about 28 inches from the floor, and the center of the passive radiator is 17 inches from the floor. A separate high-frequency module operating above 2 kHz is mounted on top of the cabinet. It is covered by an acoustically transparent black grille assembly and houses a 1-inch dome driver mounted on a flat metal plate. A downward-sloping ramp beginning at the lower edge of the tweeter dome minimizes diffraction effects that could impair the smoothness of the high-frequency response. With the grille in place, a ramp extension in its framework continues the antidiffraction treatment to the front of the cabinet. A separate black cloth grille covers most of the cabinet’s front.
Had never heard a set of these before, amazing that somehow these had slipped through our sights. Boy were we pleasantly surprised, maybe even shocked, by the presentation of these "better" Polks from yesteryear. They are FANTASTIC with every type of music we throw at them. It's a snowy Monday and we're sitting here at the shop listening to local (under-appreciated) singer/songwriter Charlie Farren. Going through his entire catalog and man, these Polks can both rock and totally handle his ballads with deft and intracacy. Taking me back to The Channel Club and 1982, lol. Speakers are in a sold 9 condition. New caps, grill cloth all around and really in super clean shape.
Come give these fabulous Polks as spin at our Lawrence shop or purchase with confidence via this website.
Polk, RTA 12C Floor Standing Speakers: $599+ applicable sales tax