Multichannel PCM and not Dolby Multichannel PCM

Hi There,

in its default state, the AppleTV outputs all audio through HDMI as multichannel PCM (either 2 channel, 5.1 channel, or 7.1 channel). When it outputs Dolby Atmos audio, a metadata stream is included on top of the channel bed with spatial panning data.

Page seven of the manual for your soundbar seems to indicate that Dolby Multichannel PCM is applying a Dolby specific upmixing algorithm to the multichannel PCM the soundbar has received.

If your goal is to upmix all multichannel PCM sources, set the sound mode on the sound bar to “Surround” or “adaptive sound”.

What you’re hearing is the soundbar taking a 5.1 or 7.1 channel mix and interpreting a Spatial Audio 11.4 mix from it. It should be more enveloping than just the 5.1 or 7.1 mix though not necessarily what the film’s author intended.

While it’s true that AppleTV outputs multichannel PCM which is uncompressed audio, in most cases, that audio was streamed to the AppleTV as lossy audio (often Dolby Digital +). An exception is lossless audio if you pay for an Apple Music subscription.

in the end, a DVD or Blu Ray will almost always sound better than movie audio streamed to the AppleTV because the source material is recorded at a much higher data rate or, in the case of blu ray, often lossless audio.

If your soundbar is in adaptive mode, I’m not really sure why you’re hearing a difference between the AppleTV and the AppleTV app on your television.

Maybe try surround mode instead of adaptive mode.

good luck