Hey prtuc2. This would be confusing to me too, the type of line level connections I have used being RCA jacks with a signal and ground for each channel.

But your MKV output is speaker level, not line. So I think you want to just hook the sub up as you usually would to speakers... another set of cables coming off the Torii speaker terminals, one going to the speakers, and one to the sub for each channel. The sub diagram shows these speaker level input connections as usual, plus and minus for each side.

Hope this helps,

Will