Correct settings to Down mix Atmos Files?

Hi, i am a new infuse user with pro subscription,
My Home theater setup is appletv4k +denon 1500 avr+epson projector + 5.1 speakers(no atmos speakers).

My question is how to play or down mix trueHd atmos MKV file(7.1 to 5.1) without loosing atmos track with infuse +apple tv 4k, i know that appletv does not support dolby atmos in true hd format. I just want to know the correct settings in infuse and apple tv such that when i play trueHd atmos file, audio is down mixed to 5.1 without loosing atmos channel. Is that possible? My understanding is that atmos channel will be mixed with surround channels, right? Please help…

Welcome to the forum!

There’s an audio setup guide here that should answer your questions.

Thanks, but i have read that page before, but its not clear what happens when you play trueHd atmos files, if i set auto in apple tv and infuse atmos channels will be downmixed to side surrounds?

Unfortunately, I don’t believe there is a way to downmix TrueHD Atmos to E-AC3 Atmos at the present time. Sorry.

ok not to EAc3 atmos, i was asking about downmixing to TrueHD 5.1

If you play a 7.1 TrueHD Atmos file in Infuse now, Infuse will send the 7.1 audio as LPCM (lossless) and discard the Atmos data.

Your receiver would receive 7.1 channels, and depending on how many speakers you have connected will decide what to do.

Some DSP modes will simply drop the extra 2 channels, others may mix them into the 5.1 output.