Q: I have a 5.1 AV system with a 1080p display. My goal is to continue to use an AVR to decode multi-channel audio from multiple sources while simultaneously obtaining a UHD/HDR/WCG picture from each of those sources.

When I make the move to a UHD/4K HDR display, can I use the TV as a switching device that sends Dolby TrueHD, DTS Master-HD, as well as Atmos and DTS:X to an AVR? Or do I need a new AVR with HDMI 2.0a and HDCP 2.2 in order to make that work?

- Thunder240
A: If you wish to enjoy UHD/4K HDR content from multiple external sources, while decoding lossless multi-channel audio formats including Dolby TrueHD, DTS Master-HD, and Atmos, your best bet is to find an AVR that features HDMI 2.0a with HDCP 2.2. Fortunately, the latest AVRs from a variety of brands already meet those specs, including some very affordable models. However, if you already own an AVR that decodes all the audio formats you need—but does not handle HDR—all is not lost.

Currently there is only one way to watch UHD HDR content with lossless multi-channel audio: Ultra HD Blu-ray. Streaming services use compressed audio formats (typically Dolby Digital +) and that includes the latest UHD/4K HDR streams. It's worth noting that DD+ can deliver an Atmos experience.

If you purchase a player with dual HDMI outputs, then you can use an AVR that does not support HDR content to decode the audio, while sending the video directly to an HDR display. However, if that AVR does not decode Atmos or DTS:X, the content will be rendered as conventional 5.1 or 7.1 surround.

Using a TV as a switching device will limit you in terms of which audio formats you can decode. Some TVs only output stereo PCM, while others offer Dolby Digital bitstream output via digital optical and HDMI ARC. I am not aware of any TV that offers lossless multi-channel audio pass-through of Dolby Atmos (or DTS:X) to an AVR using the HDMI ARC function. When it comes to surround-sound, your options would be severely limited by using a TV for source switching.

Currently, the only way to stream HDR content is by using the built-in apps of TVs that support it. I expect Roku, Fire TV, and Apple TV to offer HDR in future devices (OK, maybe not Apple). But as of now, you simply don't have to worry about switching between multiple devices that offer both HDR and lossless immersive audio.

Hopefully, gaming consoles will also have UHD HDR capabilities when the next generation arrives. I'd love to see PCs and Macs offer HDR display modes. However, given the paucity of external sources that feature HDR, you might find that waiting a bit longer before investing in an AVR just for the sake of switching between multiple HDMI 2.0a devices. For now, Ultra HD Blu-ray players with dual HDMI provide a workable solution that allows you enjoy the highest-quality HDR content—along with decoding of lossless audio formats—without requiring that you buy a new AVR.