Yes pretty much but I am only using 1 analog from the SHD to 2x4HD which is then outputted to each sub, as below:
PC -> [USB] -> SHD, then SHD analog 1 [RCA] -> 2x4 HD, then 2X4 HD analog 1&2 -> subs [RCA]
SHD XLR 1,2 -> amp1 and SHD XLR 3,4 -> amp2
I am using "vertical" biamping i.e. one...