A search for SDA2 came up with nothing so I'm casting for ideas. The SDA2 speakers have twin 6" drivers which operate in phase for Base and a dome tweater. They operate as a matched pair with a passive 12 inch resonator and crossover which drives midrange in phase on one driver and out of phase into the opposing speaker to throw the sound. As a pair they make a very smooth acoustic image and sounded great with the old 3 channel surround. Now I have a 5.1 amp. If I hook up the center that came with the polk FX surround speakers, most of the sound comes through the center and sounds like a clock radio. The components missing from this system are a descent Center and subwoofer. How does one find a matching center channel when the Side channels are obsolete and nobody even knows what they are? They aren't even in the Polk site.
