Audirvana_plug in apple equalizer

Hello,
trying to use the equalizer Apple:AUGraphicEQ in the AudioUnits config parameters, the sound quality deteriorates drastically, even eliminating the flag on the option Realtime AudioUnits control and setup.
in order to optimize the listening point I made measurements with microphone and pink noise, but I can not proceed with the EQ changes … as soon as activated the sound becomes unlistenable … does anyone know the reason?
THANKS A LOT!

k