Bones, welcome. There was a previous discussion
here relating to the AX 120 terminals. The picture there(apparently of a later version than the ones you have)shows that the output terminals are the top ones. It would seem likely that yours follow the same pattern.
The only specs seem to be the ones in
this table.
You don't mention exactly how you're planning to use the two subs, but if you're thinking of setting them up as "stereo" subs(although there's actually little or no stereo bass in recordings), you'd connect just one of the stereo channels to each AX 120. If you then feed the front speakers from the speaker level outputs on the AX 120, apparently there's a 120Hz high-pass filter on those outputs, which'll roll the front speakers off below that frequency.
