Why does SoundID Reference lower my output volume? Safe Headroom feature explained.
In this article:
Safe Headroom feature
The Safe Headroom feature in SoundID Reference is implemented to ensure that even the most sensitive frequencies won't distort. The output is lowered when the Safe Headroom feature is enabled. SoundID Reference cuts and boosts certain frequencies to compensate for the inconsistencies in a particular output's frequency response. Boosting certain frequencies creates a risk that the digital audio will peak above 0 dB and clip. The Safe Headroom feature lowers the output volume by the maximum peak in the correction curve to prevent the output from clipping (prevents gain-staging related audio distortion).
You can disable Safe Headroom and turn the volume fader all the way up at the risk of introducing clipping.
Safe Headroom logic
This feature has a logic that was implemented to avoid sudden gain jumps. It is being followed in the standalone app and plugin. The lowest dB of the preset already loaded will be applied to all future presets, so as not to have any gain differences when switching between them, as shown below. This consistency ensures the most convenient mixing and listening experience.
- When loading multiple presets, newly added profiles will adjust to the lowest Safe Headroom volume of the loaded presets
- The option to readjust the volume after loading the profile remains and will be saved
4 comments
SoundID lowers the monitor output even with safe headroom off, and output all the way to 0db.
Why is that? is there a way to make sure what comes out of the audio interface is the same when refference is enabled or not?
Hello Philip Iliades ,
Thank you for reaching out!
I have created a support request regarding the issue encountered, it would be best to look into this in greater detail.
As per the Audio interface and the calibrated output, it would be best to test if it's enabled by using a more pronounced target curve such as a Car stereo or MacBook speaker to see if the calibration is taking place.
I hope this helps!
I'm glad I checked here - as this is a serious issue for us running the Multichannel SoundID on a major film project. The setup was so easy btw - a real pleasure dealing with such innovative and progressive method of implementation.
Currently any Protools session we run when started or restarted requires the SoundID plugin to be deactivated - then re-activated - otherwise the Level is literally around 10dB low as described above by Philip (with the Safe Headroom Disabled), without exception.
I'm running a Mac Studio / Sonoma / PT 2024.3.1 - but note this was also happening on my iMac running Monterey and PT 2023.12.1.138 (?).
I have a question, I need to have my room calibrated at 74, 76, 79 db, usually before calibrating I set my speakers to 79 db and then calibrate, and I put some marks on the master of the monitoring control. but the sound id reference drops the safe headroom limiter at the output by 12 points,
how can I make my room stay at 79 db without taking the safe headroom to 0?
What meaning do those 12 dB that result from the measurement have?
Would it be better to calibrate, leave the limiter where it is at those -12 points of the sage headroom and then increase the volume to the master monitoring control?
Or would it be better to raise the speakers to 91 db, calibrate and leave the -12 points of the safe head room limiter below?