This appendix provides calibration instructions for HD-series audio interfaces, including the HD I/O and 192 I/O systems with mixed HD-series audio interfaces.
The following procedure describes a method for calibrating both outputs and inputs to the same reference level using either an HD I/O or 192 I/O interface. You will need a VU or dBu meter to perform this procedure, or you can use a multimeter (+4dBu = 1.23Vrms). These steps describe calibrating one channel. Repeat the process to calibrate additional channels.
To calibrate an HD I/O or 192 I/O interface:
1. In Pro Tools, create a new session by choosing FILE > NEW SESSION.
2. Choose SETUP > PREFERENCES ...