Original s/u on Tyros1 and Tyros4 included 1 Left and 1 Right RCA connection to small mounted speakers plus a dual cord output to Yamaha sub woofer.
When plugging to a keyboard amp, cords from L out and R out without the Yamaha speakers, I get great sound but I'm not sure if I'm loosing some of the style output that was sent to the Yamaha sub woofer. My keyboard amp (Roland KC550) has a 15" main speaker. Do I need to find a means to channel the output from my keyboard (sub woofer) to the amp?