BTW- I recently performed a bunch of tests trying to find a set of baseline settings for the most accurate Atmos rendering. Since I have two Atmos systems with speakers and two headphone systems (Smyth A16 and the Apple AirPods Max), I was able to compare renderings across them. The A16 is very accurate, and since it does not have Audyssey, a more direct reflection of the source encoding.
Pre-requisite: Have run the guided setup that uses the Mic to determine levels and distances for the speakers. Ideally, a room correction measurement is also performed, following the guidelines "Official" Audyssey thread Part II
AVR/Preamp settings
Note: these must be reviewed/set while actually playing an Atmos track from the desired source, as some options are hidden if the current audio stream does not support them.
These settings are for the common Denon & Marantz processors, other manufacturers and other DRC systems might call these different terms or have additional elements that might need adjusting.
In general, the idea is run with as few level-altering options as possible.
In Audio->Surround Parameters
- Loudness Management: Off
In Audio->Audyssey
- MultEQ XT32: ON (if a calibration was run at setup)
- Dynamic EQ: OFF (this messes with relative levels and messes with positioning, turn it off)
- Dynamic Volume: OFF
- LFC: OFF
- Target option is to taste, but generally ‘reference’ is what is used to mix movies
In Options->Channel Level adjust
- Set all channels to zero (assuming the calibration at setup is correct).
- Subwoofer tweaks of a couple of dB are fine
In Options->Dialog Enhancer
- Set to OFF
This should deliver the greatest fidelity with regards to positional accuracy and 3D soundfield.
Note that this is a baseline geared towards optimizing positional rendering, you will likely wind up tweaking from there. But I found that even a 1dB level change on overheads would subtly 'move' object renderings. Atmos depends on timing and level matching to recreate the sound at the specified locations, and the +3dB that DynamicEQ can apply to rears and top-rears totally warps the image.
Mine matches these settings to a T except I turned off the MultEQ XT32. And so far I haven't experienced the noise on my Marantz AV7703. Also I haven't seen a software update for my 7703 for quite some time. Which could also be why Robert's newer unit may have a software or firmware update to combat this issue?