Setup Dual Subwoofer with Expert 400

[sam1000]

This should work. You might need to open a case with support. But in the meantime, try configuring mono sub from master, and use a Y cable if you have one handy.

Hi Sam1000,

Have you done a similar setup?

what should be the pre-out setup? mono or stereo?

I use mono->dspeaker 8033s-II->dual sub.