Yes this is what I'm trying to do. However on the si expression I can't see how to setup an insert on a mix buss output. That is what I need help with. There are no videos online to show this and the manual is even worse.
In the insert setup menu I can select all physical ins and outs and digital ins and outs to the card.. but can't see for example a mix buss out for send and returns. I can send my inputs to sub groups.. and I can send the sub group to the master outs.. but I need to send the mix busses to an insert before the master, for waves. The manual states inserts can be assigned to mix outs.. However with it only stating in the menu channel numbers. I wouldn't know which channel number these would be under.
On the SI consoles you assign the insert processing to channels in the
insert menu, not in the
insert setup sub-menu. The
insert setup sub-menu is for assigning the xlr or card I/O for each insert. To assign each insert to an audio channel, you need to go to the insert menu (not insert setup), select the desired channel on the console with that channel fader's select button, and then use the dropdown next to the insert on the touchscreen to put that insert processing onto your selected channel. It's a little tricky to explain but it's actually very simple once you do it. You scroll through the inserts with the knob and then push the knob to open the dropdown, if I remember correctly.
I don't remember if I've ever put an insert on mixes - I normally use them on input channels, but it would work the same way, I'm sure.
I hope that helps!