The Polk Audio SDA-1B's were a transitory model between the original SDA-1A's(1985 - 1986) and the upgraded SDA-1C's (1987 - 1990). Known, as with all of Polk's SDA series, for their crosstalk elimination, the 1B's were touted as being able to give a clear and defined stereo image, much more so than other other floor standers of the day and have yet to be surpassed by products of today. Unlike other technologies of the time, the Polk's achieved this effect via a second set of drivers on each speaker that were wired into a passive crossover
tuned to inverse the other channel's signal.
Driver Complement Subwoofer 1 - 12" Diameter (30.48cm) fluid-coupled subwoofer Midrange 4 - 6-1/2" Diameter (16.51cm) tri-laminate polymer bass-midrange drivers Tweeter 2 - 1" Diameter (2.54cm) Polk SL 2000 silver coil dome tweeters Electrical Overall Frequency Response 14Hz - 26000Hz Nominal Impedance 4 ohms Recommended amplifier
Power 10-500 w/channel Efficiency 92 dB Crossover 50Hz and 2000Hz Dimensions Cabinet Size 13-1/2" H x 16" W x 12" D (34.29cm H x 40.64cm W x 30.48cm D) Shipping/Other Total Shipping Weight 85.00 lbs. (38.56kgs)