The magenta line is the applied correction. No correction at all is applied up to 70-80 Hz. Might be coincidence that this is also the sub crossover frequency or not. Is that a regular powered sub connected to the subwoofer output using a single line level RCA cable?
If it sounds good to you then it's all good. But maybe it could even sound better.
The default value for RC is to only apply correction between 40 Hz and 4000 Hz. Your graph looks like this setting either has been changed of the limitation wasn't applied correctly by the Ultra. Things to check: Reboot the Ultra and restart the app. On the first RC screen tap the cog icon in the upper right as mentioned by Smartplug and take note of the settings there.
Default values are:
Curve: B&K
Equalizer: 40 Hz to 4000 Hz
Max Gain: 10 dB
Max Q: 10
Personally I like to reduce max gain a little and keep max Q below 5 to keep RC from correcting even the smallest peak but that's a matter of preference.
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