Originally Posted by frankthetank966
So even movies that say Dolby enabled on Apple TV are not producing true Dolby sound? What listening mode do you chose for Apple TV? I'm not sure what you mean by lossless format.
Also, I am using Amazon music most of the time and streaming through Airplay. I thought the receiver was supposed to improve the sound quality. What setting do you suggest?
There are many flavors of "Dolby". Dolby Digital is lossy, which means that during compression, some information that is considered less important is thrown away, to save on bandwidth. The majority of streaming services, as well as broadcast TV and DVDs, use Dolby Digital for 5.1 audio (if they aren't using stereo or even mono).
Dolby TruHD is lossless, meaning that the compressed audio can be unpacked and be identical to the original recording. This format is typically found on BluRay discs.
Dolby Atmos is an add-on which adds height via ceiling speakers or reflected sound, and is not possible with a 5.1 setup (which I share with you). And Dolby Vision isn't even an audio format.
(And before anybody yells at me, DTS is a competitor to Dolby, and has equivalents to all of Dolby's audio formats, but these are typically found on shiny discs and not broadcast or streaming.)
When you watch movies on your Apple TV are you watching through the Apple Movies app, or Netflix, or some other app? Each may do something different with audio. In any case, unless it specifically says "Dolby TruHD" you are almost certainly getting Dolby Digital, which is lossy. This can sound quite nice, and a Denon receiver will certainly make the most of it -- but it can do even more with a higher-quality source.
As I write this I'm listening to the first disc in the Chicago Quadio Box, which is an audio-only BluRay set of the original quad versions of the first 10 or so Chicago albums, remastered in DTS-HD (the DTS equivalent of Dolby TruHD), and I wouldn't dream of listening to it in any other format. However, I also stream a lot of music through my Apple TV, and watch a lot of Netflix; for these I tend to prefer multi-channel stereo, because IMHO it makes stereo music sound richer and dialog easier to hear. Others here will certainly have other opinions.
I would urge you to keep your rear speakers, pay closer attention to exactly what audio formats you are getting, and experiment.