I am not sure why you have the noise you have.
I know what I am going to say won’t fix the issue of noise however, is it worth setting up the 568.2 and 3 Genelecs as full range, to assess Trifield? I know that means no subs and no Dirac but it would surely be the easiest way for some level of assessment. This does assume you have an alternative stereo source to connect to the 568.2.
Similar to 3dit0r, I do think that running the 568.2 without the NAD would yield the best results. I would consider a miniDSP to help integrate the subs, in the long term.
Main: Marantz SR8015 / Polk Audio Reserve R500 / Bang & Olufsen Beolab 4 / Arendal 1961 1V / Oppo 203 / WiiM Pro Plus / Apple TV 4K
Spare: G68ADV, HD621,DSP5000.2 & DSP5000.2 HC. ATC SCM20PSL, C3C. Rotel RMB-1077. Bang & Olufsen Beolab 1 & Beolab 7.1. Kef Q150. Dynaudio Xeo 2.
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