7.1 surround test, MX121

Make sure you have configured your processor correctly and that you have the right speaker configuration applied to the source.

Some AVR’s let you set up a speaker configuration by source, so input1- stereo, input 3- 7.1, and if you don’t have that mapped correctly you won’t get anywhere.

Make sure you connect your AppleTV directly to your receiver for this testing.  If you route through your TV first you may have misset HDMI / ARC settings.

Thanks! I’ll give it a go again tonight.

Most movies streamed are actually in Dolby Digital 5.1, and some are even in Dolby Digital 2.0 (basically stereo). The movie itself has to be encoded to have 8 discrete channels for 7.1 content. If you can’t find any movies on streaming, maybe buy or rent a bluray from this list:

https://forum.blu-ray.com/showthread.php?t=159814

I believe Netflix only has 5.1 content, but some stuff from Amazon Prime supports up to 7.1.

There was a lot of recording with Dolby EX, which was kind of 5.1 encoding + matrixed rear speakers for the extra 2 channels. They’ll still show up on Netflix as 5.1

The path was identical to Dolby 5.1, with the extra that if you had the right decoder you could tell the 4 surround speakers apart.

AFAIK, Atmos and the DTS equivalent go away from discrete channels by the use of object based sounds.  There's no 8.1 or 11.1 or 15.4 channels.  It's all up to the decoder now. It's no longer discrete channels, it's discrete sounds in a location and up to the decoder to decide what speakers it goes to.

Okay—think I understand now. Essentially there is little 7.1 actually available, so I tried Dolby EX tonight with a 5.1 blu ray and the rear speakers fired up.

thanks for the help