I remember reading that the Dolby Atmos container (either Dolby TrueHD or Dolby Digital Plus), has also a Core 5.1 or 7.1 or even a 2.0 already “pre-mixed” apart from the Atmos track with metadata to decode the objects. If this is true, theoretically, almost all AVR that don’t decode Atmos, but support Dolby TrueHD or Dolby Digital Plus, would play the core 5.1/7.1/2.0 in a similar way DTS core is embedded in a DTS HD-MA track. And no content would be lost never. Just ‘downmixed’ to the available speakers.
Now with my tests results:
I have tested from Dune HD Solo 4K, Dune HD PRO 4K and Oppo 203 players always with bitstream audio output.
I tested in two environments:
- 5.1 speakers with an Onkyo TX-SR607 (2010)
This AVR has no Atmos decoding at all.
- 7.1.4 speakers with a DENON AVC-X8500H (2018)
Although this is a full Atmos system, I tested also with Dolby TrueHD Sound Option, without decoding the Atmos to see the difference.
Below I will tell only when the corresponding signal does not go to the corresponding Speaker, because it does not exist or because the decoder does another thing. I mention each pair of speakers, without repeating ‘Left’ and ‘Right’. All the rest of speakers not mentioned have worked OK as it should.
Test 5.1.2 (5.1 speakers with ONKYO-No Atmos)
The AVR shows a DDTrueHD signal.
- Top Meddles go to Surrounds.
Test 5.1.2 (7.1.4 speakers with DENON-No Atmos decoding)
The AVR shows a 7.1 DolbyTrueHD signal.
- Surrounds go to Surrounds Back. I was expecting going to surrounds, but in a 7.1 layout, perhaps is better to send 5.1 surround channels to Surround Back speakers that could be at the more right recommended angle. Denon does that.
- Top Meddles go to Surrounds.
Test 5.1.2 (7.1.4 speakers with DENON-Atmos decoding)
The AVR shows a Dolby Atmos signal.
- Surrounds go to Surrounds Back. I was expecting going to surrounds, but in a 7.1 layout, perhaps is better to send 5.1 surround channels to Surround Back speakers that could be at the more right recommended angle. Denon does that.
- Top Meddles go to both Top Front and Top Rear. Thus, generating the image as if you had Top Meddles.
Test 5.1.4 (5.1 speakers with ONKYO-No Atmos)
The AVR shows a DDTrueHD signal.
- Top Fronts go to Fronts.
- Top Rears go to Surrounds.
Test 5.1.4 (7.1.4 speakers with DENON-No Atmos decoding)
The AVR shows a 7.1 DolbyTrueHD signal.
- Surrounds go to Surrounds Back. I was expecting going to surrounds, but in a 7.1 layout, perhaps is better to send 5.1 surround channels to Surround Back speakers that could be at the more correct recommended angle. Denon does that way.
- Top Fronts go to Fronts.
- Top Rears go to Surrounds Back.
Test 5.1.4 (7.1.4 speakers with DENON-Atmos decoding)
The AVR shows a Dolby Atmos signal.
- Surrounds go to Surrounds Back. I was expecting going to surrounds, but in a 7.1 layout, perhaps is better to send 5.1 surround channels to Surround Back speakers that could be at the more right recommended angle. Denon does that.
Test 7.1.2 (5.1 speakers with ONKYO-No Atmos)
The AVR shows a DDTrueHD signal.
- Surround Back go to Surround.
- Top Middles go to Surround.
Test 7.1.2 (7.1.4 speakers with DENON-No Atmos decoding)
The AVR shows a 7.1 DolbyTrueHD signal.
- Top Meddles go to Surrounds
Test 7.1.2 (7.1.4 speakers with DENON-Atmos decoding)
The AVR shows a Dolby Atmos signal.
- Top Meddles go to both Top Front and Top Rear. Thus, generating the image as if you had Top Meddles.
Test 7.1.4 (5.1 speakers with ONKYO-No Atmos)
The AVR shows a DDTrueHD signal.
- Surrounds Back go to Surrounds.
- Top Fronts go to Fronts.
- Top Rears go to Surrounds.
Test 7.1.4 (7.1.4 speakers with DENON-No Atmos decoding)
The AVR shows a 7.1 DolbyTrueHD signal.
- Top Fronts go to Fronts.
- Top Rears go to Surrounds Back.
Test 7.1.4 (7.1.4 speakers with DENON-Atmos decoding)
The AVR shows a Dolby Atmos signal.
- Of Course, All go to where it should go.
Test 9.1.6 (5.1 speakers with ONKYO-No Atmos)
The AVR shows a DDTrueHD signal.
- Wides go to Front.
- Surrounds Back go to Surrounds.
- Top Fronts go to Fronts.
- Top Meddles go to Surrounds.
- Top Rears go to Surrounds.
Test 9.1.6 (7.1.4 speakers with DENON-No Atmos decoding)
The AVR shows a 7.1 DolbyTrueHD signal.
- Wides go to Front.
- Top Fronts go to Fronts.
- Top Meddles go to Surrounds.
- Top Rears go to Surrounds Back.
Test 9.1.6 (7.1.4 speakers with DENON-Atmos decoding)
The AVR shows a Dolby Atmos signal.
- Wides go to Front. Here it would be good that Wides would go to both Fronts and Surrounds to generate the image. But it seems the Test Atmos signal demo for the Wides is not a ‘floating object’ if that terminology exists.
- Top Meddles go to both Top Front and Top Rear. Thus, generating the image as if you had Top Meddles.
Test TrueHD Channel 7.1
This Test works OK for each system, with the same speaker mappings as said before.
A NOTE about the levels of back channels.
I have notice on both ONKYO and DENON that back channels, that go to Surround, Surround Back and Top Rear Speakers, have a bigger level than the rest. Something like 6 to 10 dB more with the appreciation of my ears.
I have checked with the AVR test tones and revised my Audyssey calibration and tested with other demos like the Helicopter demo, and I find my systems more or less well calibrated.
Has anyone notice something similar with these test files?