Question: does hdmi arc support 4k?
Answer: It's worth noting ARC doesn't allow you to bitstream the full-fat high-quality codecs such as Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio or DTS:X soundtracks that you find on Blu-rays and 4K Blu-rays. It simply strips out the core 5.1 data stream.