What is Safe Headroom?
Safe headroom is an output limitation feature meant to reduce and avoid distortion that could arise by volume increases in specific frequencies resulting from calibration.
The safe headroom output reduction amount (in negative values) is calculated during measurements. The safe headroom is set in the plug-in when loading the headphone or speaker calibration profile.
The safe headroom feature can also be disabled allowing the user to increase the output to equal the 0.0 dB value which would be equal to the plug-in input signal level. Disabling the safe headroom would not change the output level without the user's action, but simply remove the limit. However, enabling Safe headroom would decrease the output value to the limit value if it was set higher while safe headroom is disabled.
Multichannel calibration profile Safe headroom
Safe Headroom has 3 states: Specific, Unified, and Disabled.
Specific: Each channel group gain is limited by the amount equal to the highest boost of the channels of the channel group. Safe Headroom value is different between channel groups. The main gain slider (master gain) has a Safe Headroom value that matches the lowest channel-group Safe Headroom value for the calibration profile.
Unified: All channel-group gains are limited by the same amount (largest boost out of all channels). Same as the stereo implementation of "Enabled". The main gain slider (master gain) has a Safe Headroom value that matches the Safe Headroom value of all channel groups for the calibration profile.
Disabled: Gain is not limited for any channel groups or master gain.