You can use either a single LFE RCA cable or stereo white/red RCA cable.
Connect FROM your powered speaker's 'Subwoofer' output TO your subwoofer's 'Left' RCA input or the subwoofer's LFE input.
For stereo RCA cables, just use the left/white RCA cable, and leave the red RCA disconnected to prevent an accidental ground loop.
** Please note: a 3.5mm/stereo mini cable will not work with the 'Subwoofer' output on the back of your A1/A1-MR speakers. **
Connect FROM your powered speaker's 'Subwoofer' output TO your subwoofer's 'Left' RCA input or the subwoofer's LFE input.
For stereo RCA cables, just use the left/white RCA cable, and leave the red RCA disconnected to prevent an accidental ground loop.
** Please note: a 3.5mm/stereo mini cable will not work with the 'Subwoofer' output on the back of your A1/A1-MR speakers. **