strongly recommend you read the manual -> http://www.Meridian-audio.info/public/HD621-userguide-a5%5B1292%5D.pdf

IMHO, it is more a matter of configuring the HDMI devices feeding the HD621 than the other way around.



Primary: 818v3+ID41, M6 stereo pair, M SpeakerLink cabling, Sonos+96kHz Cullen, silver DSW
HT: Marantz prepro, 271, DSP3300, 8K SE FL/FR pair, DSP M6x2, DSP320x4 (ceiling), black DSW, 520 RL/RR rear in-walls
Living Room: G65, 640 L/R in-walls, UHD722, MS600
Vac. Home: G61, HD621, 4xDSP3100, DSP3100HC
MDMS:NUC/ROCK+TrueNAS Core 12.0 ZFS file server