Polk RTA 12B (circa 1981–1982)

Not much is documented about the Polk RTA 12B beyond period audio reviews and a brief mention as an award winner. The record shows a full-size, floor-standing loudspeaker at the top of Polk's "Audio Monitor Series" line in the early 1980s. Audio (August 1982, p.14) noted that the RTA 12B had won a Hi Fi Grand Prix Award, and that the later RTA 11 was a less expensive and less complex version.

According to HiFi/Stereo (January 1982, p.36), the RTA 12B was a 4-ohm system. Its frequency response was rated flat within ±3 dB from 50 Hz to 20 kHz, with a "virtually uniform phase-vs.-frequency characteristic." The same review, done by Hirsch-Houck Laboratories, described the cabinet as a real walnut wood veneer. Each speaker weighed about 75 pounds. The design used multiple 5½-inch drivers with staggered crossover frequencies, mounted in physical symmetry, and a tweeter fuse provided protection. The crossover network sat inside the high-frequency assembly, and the grille covered most of the cabinet front. HiFi/Stereo (January 1982, p.40) added that bass distortion measured between 1 and 2 percent from 100 Hz down to 32 Hz at lower power levels, and rose at higher output.

Almost nothing else is recorded about the RTA 12B. No production run, original price or detailed driver complement has turned up in the available documentation.