i might be wrong, but isn't the Comp16 only mono? if so, you can only use it on one channel at a time. are you looking at compressing whilst recording or whilst mixing?
if you want to use it whilst recording you'd need an external preamp as, although it has an XLR input, it's a balanced line input rather than a mic in, plus it doesn't have phantom power. so, to use it in the recording path, the signal chain would be;
Mic -----> External preamp in ------> External preamp line out -------> Balanced in Comp16 ------> Balanced out Comp16 ------> Audiobox Line In
if you want to use it for mixing, it can be a bit frustrating as
the audiobox only has 2 outs, but it's not impossible and just takes some setting up in your DAW and the presonus universal control software. I have
the Firestudio Mobile which only has two main outputs and to send stuff to my outboard i do the following;
in my DAW, i set the output of the track i want to send to the output to "Output 3-4", and pan it hard left so that it only comes out of output 3, or the Left output on the sound card.
in universal control, in the main outputs i mute everything except output 3-4
then set up my signal chain like this:
Left Output on Soundcard ------> input on gear ------> output on gear ------> line input channel 1 on the sound card
in universal control, i open the "headphones" tab and mute everything except "input 1" and "output 1-2" so that i can hear both the signal coming back from the outboard equipment and the rest of the mix from my DAW
in my DAW i create a new track with "input 1" and when i'm happy i record the processed signal back into my DAW.
This method does create some latency on the recording back in so you have to time align it by hand. however, you can set up latency compensation in some DAW's and some DAW's have a plugin that does all of this for you (although you still have to do the physical plugging in yourself
).
the other big problem this creates is you have to monitor this process through headphones which isn't ideal, but as long as you check it back through your speakers once it's done you should be fine, and this often means unplugging and replugging in your speakers if they're on the main outputs
