I use SpeakerLink and have new Cat 6 shielded cables through the walls. The crackling is coming for all 5 speakers. I can re-upload the firmware also.

Kishore, if that fails I will pull it from the rack soon as I get time on the weekend and have a look at the PS wires like you suggested.

Theatre Room: Sony 4K VW500ES, 861v8+ID41, HD621, DSP6000's, DSP5000C, DSP5000's, Oppo 205, Sat STB, XBox One X, Stewart Cinemascope Screen, QNAP TVS 1271U-RP (96TB) with Sooloos/Roon core pkg.