Bob: The best argument I can make is that by having the audio and video processing in the same device, delays caused by time required to process the two different signals can be accounted for and adjusted. If the video delay is created in the TV after the audio signal is split out, thert is no way to synch the signals again. This is of course assuming that the TV manufacturer is willing to pay to put in the processing capabilities.
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Living Room 24x18 open 1/2 flight up to a raised dining room/hall 24x12
Outlaw 976 pre-pro running 5.1 system
Outlaw 750 for Artison Masterpiece LCR and 2 NHT SuperZeros rears
Velodyne Servo FX-1200
LG OLED65C8PUA via HDMI2 to/from 976 HDMI ARC
Roku Ultra
Samsung BD-D5500 BluRay
Amazon FireStick 4K to 976 Aux HDMI input for Amazon Music Ultra