You really do refuse to do it my way. Ah well – just makes it more difficult. You'll have to read the Manual instead.

If you look at routing #27 in the Manual, or using the Routing Utility, you will see that the analog outputs are driven by FW1-4 (via DSP A and B) – this is why you hear nothing on the speakers from the mic. The H8000 analog inputs feed FW5-8 – you will have to setup your aggregate device so it uses some of these.

I really would suggest that you read the Manual and try out the Routing Utility – both of these will be helpful.