Sub - Rythmik LV12R
AVR - Pioneer 1222
Again, any decent cable with an RCA connector on one end and two on the other. OTOH, a regular straight-through cable should do it anyway.
The reason for two inputs is to permit stereo users to connect the unbuffered/unisolated L and the R outputs to a single sub without shorting the channels and eliminating stereo separation in the main speakers.