In your recommended parametric settings for the Sennheiser 560S headphones, the first setting is for a low shelf filter at 105 Hz, Q of 0.7, and a gain of 9.1 dB. With the recommended overall gain setting of -6.4 dB, that pushes the gain well into the red when used with Equalizer APO. That 9.1 dB recommendation can't be right...
The positive gain is below 20 Hz. AutoEq only optimizes 20 Hz to 20 kHz range. There's not really ever any content below 20 Hz so this is not a concern.
In your recommended parametric settings for the Sennheiser 560S headphones, the first setting is for a low shelf filter at 105 Hz, Q of 0.7, and a gain of 9.1 dB. With the recommended overall gain setting of -6.4 dB, that pushes the gain well into the red when used with Equalizer APO. That 9.1 dB recommendation can't be right...