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[kr4]

As the number of source channels that some of us are faced with now greatly exceed the number of channels in our playback system, the issue of downmixing in MC is becoming important.  For example, if I have a 14 channel source and specify a 7.1 channel output (playing now), what is happening?  Are the additional channels simply ignored or is there a real downmix option?  Do I have to do it manually?

(I searched the WiKi and found nothing relevant that was not archaic.)

[eve]

As the number of source channels that some of us are faced with now greatly exceed the number of channels in our playback system, the issue of downmixing in MC is becoming important.  For example, if I have a 14 channel source and specify a 7.1 channel output (playing now), what is happening?  Are the additional channels simply ignored or is there a real downmix option?  Do I have to do it manually?

(I searched the WiKi and found nothing relevant that was not archaic.)

14ch source > 7.1 is going to need your own logic to downmix. What's the channel layout of the 14ch source supposed to be?

[kr4]

Good question.  This is a typical 14 channel file:
"03_Piano Concerto in C sharp minor, Op. 30 - 3. Allegro_ADMBWF.wav"
They also come in 10 and 12 channel varieties but without any annotation of channel identity.

Kal

[AGAWA]

https://professionalsupport.dolby.com/s/article/Dolby-Atmos-ADM-Profile-specification?language=en_US

[mattkhan]

Assuming they are atmos then I guess the channel lists in https://developer.dolby.com/globalassets/technology/atmos/additional-channels-for-immersive-audio.pdf should be accurate, I guess downmix to 7.1 is technically straightforward (mix the height channels into the corresponding base channels) but the weights to use are unknown

[AGAWA]

https://support.apple.com/en-gb/guide/logicpro/lgcp8118444e/11.0/mac/13.5

[mattkhan]

https://support.apple.com/en-gb/guide/logicpro/lgcp8118444e/11.0/mac/13.5

Link says nothing about downmixing height channels as far as I can see, can you point to something in either link you posted that refers to it?

[AGAWA]

my guess is that height channels carry artificial product of Dolby Atmos only to be used in full configuration, ie through height speakers. Why would one mix these into original soundfield.

[mattkhan]

If the heights contain object content then you could reasonably expect that content to be present in a 7.1 mix from the same original source, where this mix comes from is another question