[brown274]

I have the A5's and they have rca sub outs. How would I hook these up to a HSU STF-1 ?

Is there a RCA> sub in single cable?

 

[El_Doug]

I have honestly never really seen any such cable. However, you only really need to connect one of those to your sub, and can probably leave the other unconnected.

The reason for this is two-fold. First, LFE is typically a single channel of data in a surround mix, and thus in a stereo mix, the same bass signal is being sent to both channels. Secondly, at those low frequencies, directionality becomes almost meaningless - any subtle nuance in the soundstage wont even be realized by the time it hits your ear, even in the near-field.

I see no reason not to test this setup out, and see if you like it - should save you a lot of trouble

If this turns out to be unsatisfactory to you, you could always figure out some way to make a cross-feed-esque connection for your RCA cables, that would combine both channels into one.

Of course, nothing is stopping you from buying dual subs