Polk Audio LEGEND L200 User Guide 2 - Page 4

EXPERIENCE TRUE STEREO In 1985, Polk Audio stunned the audio world with the flagship SDA-SRS speaker, which featured Polk-patented Stereo Dimensional Array (SDA) surround technology. Having already excelled in the making of the Legend series, Polk engineers went a step further to dramatically improve SDA-PRO™ True Stereo. Newly patented design employs a special "Head Shadow" filter in the dimensional array, which is built to more exactly match - and therefore cancel out - interaural crosstalk (IAC). An additional patent was granted for the L800's uniquely designed 15-degree angled baffles. This design angles the transducers more precisely toward the listener, which removes any loss of high frequency extension and the need to "toe-in" the loudspeakers. Available only on the new Legend L800. SDA-PRO delivers the most lifelike, detailed imaging you have ever heard - it is the only True Stereo™ loudspeaker. Don't believe us? Go listen.