midi – connecting Allen and Heath SQ7 to Pro Tools

The Allen & Heath SQ7 is designed to act as an audio interface (with adequate drivers). Then with Protools, you should have a menu “Setup/Play back engine” where you can indicate which audio interface you are using.

Note that you are not clear about your installation. I guess (just an hypothesis) that external speakers are connected to the SQ7, then choosing the SQ7 as the Pro tools audio interface seems adequate.

You are talking about something (what?) to be connected to the SQ7 with an “AUX cable”. You should indicate what you are encline to connect to the SQ7. If the SQ7 is audio interface of Protools, all audio inputs (hardware synthesizer, guitar, microphone…) must be connected to the SQ7. I don’t know how you expect to hear them if they are not connected.