I plan to go into my Mac Pro via the following:
analog mixier >Alesis HD 24 (for converters) > RME 9652 card > Mac Pro
A friend does this and it works great for him, except he goes into a PC and mixes inside his computer.

I want to mix "outside the box" - in other words, via my analog mixer and rack gear.  Can I do so ?  i.e. Mac Pro > RME 9652 > Alesis HD 24 > analog board ?

Thank you for your help