What Shield TV audio settings do you use?

[justinrh 208]

What audio settings do you use on your Shield and why?

I know I don't know what to do with these:
- "Match Dolby/PCM Audio Levels"
- "Match Content Audio Resolution"

Why would I want to use either of the above?

(Sometimes I think vendors make settings just to make settings!)

[Luke 39394]

How is your experience with leaving them at defaults?

[justinrh 208]

LOL  I was just thinking about that today.  I don't recall what all the defaults are, and the ones I have flipped I haven't really 'tested' them, so I can't say.  And then you have all the different scenarios with different media where it may or may not affect your experience.

[HiveHivemind 1]

Signed up to help on this one. Breaking it down:

Match Dolby/PCM Audio Levels

Every digital audio is PCM, from the basics, but encoded differently. One of its encodings approach is Dolby Audio, this having reference audio levels (volumes) for home theater listening, which is a quite old standard nowadays albeit used. They scope 85dB average, 105dB peaks in any satellite speakers (front left/right, central, side left/right, surround left/right). This setting will set any and every digital audio source (PCM) being passed through (or decoded) and level it to Dolby reference. It can help improve the dynamic range by using a standard. Netflix content has narrow reference levels and by matching Dolby it gets closer to the dynamic range of it, for example.

Match Content Audio Resolution

You might be familiar with the high-resolution audio term or going through Windows Audio Settings and seeing CD-quality, DVD-quality, and Studio-quality as audio quality options. As an industry standard, CD is the equivalent of 44.1kHz at 16-bit PCM audio, while DVD is commonly 48kHz at 24-bit, and Studio is 96kHz - 192kHz at 24-bit. It illustrates how many times per second it can sample (x times 1000 Hz) and how much data it can hold (2¹⁶ or 2²⁴ different numbers representing data per sample). High-res audio starts beyond 44.1kHz at 16-bit and the term is normally used for 96/24 or 192/24.

This option will not touch the audio resolution (sampling and bit depth) and just pass it as-is via HDMI to the input device, assuming the connected device supports it (not every does).

 

I have both enabled. I'm running the Shield in an LG CX and a Samsung Q950A and both support the most common high-res lossless audio formats, although the TV only via passthrough since by itself it caps at 44/16. I passthrough all the data digitally through the TV to the soundbar that, then, decodes it and converts to analog.

Hope that helps.

Edited February 5, 2023 by HiveHivemind

[paradox_actual 0]

On 05/02/2023 at 02:16, HiveHivemind said:

Signed up to help on this one. Breaking it down:

Match Dolby/PCM Audio Levels

Every digital audio is PCM, from the basics, but encoded differently. One of its encodings approach is Dolby Audio, this having reference audio levels (volumes) for home theater listening, which is a quite old standard nowadays albeit used. They scope 85dB average, 105dB peaks in any satellite speakers (front left/right, central, side left/right, surround left/right). This setting will set any and every digital audio source (PCM) being passed through (or decoded) and level it to Dolby reference. It can help improve the dynamic range by using a standard. Netflix content has narrow reference levels and by matching Dolby it gets closer to the dynamic range of it, for example.

Match Content Audio Resolution

You might be familiar with the high-resolution audio term or going through Windows Audio Settings and seeing CD-quality, DVD-quality, and Studio-quality as audio quality options. As an industry standard, CD is the equivalent of 44.1kHz at 16-bit PCM audio, while DVD is commonly 48kHz at 24-bit, and Studio is 96kHz - 192kHz at 24-bit. It illustrates how many times per second it can sample (x times 1000 Hz) and how much data it can hold (2¹⁶ or 2²⁴ different numbers representing data per sample). High-res audio starts beyond 44.1kHz at 16-bit and the term is normally used for 96/24 or 192/24.

This option will not touch the audio resolution (sampling and bit depth) and just pass it as-is via HDMI to the input device, assuming the connected device supports it (not every does).

 

I have both enabled. I'm running the Shield in an LG CX and a Samsung Q950A and both support the most common high-res lossless audio formats, although the TV only via passthrough since by itself it caps at 44/16. I passthrough all the data digitally through the TV to the soundbar that, then, decodes it and converts to analog.

Hope that helps.

Hey thanks for  the explanation.

If my TV (LG C3) and Soundbar (Hisense AX3120G) support all formats, why would I want to have the shield process any of it? should I not turn those off to make things run smoother?

Or do I have it backwards with matching content audio resolution and I should leave it enabled?

What about dolby audio processing in general, if the devices support it, do I need it on, do I lose/gain what from having it on/off etc?

 

Thank you.

[rekit 9]

On 6/12/2024 at 9:25 PM, paradox_actual said:

Hey thanks for  the explanation.

If my TV (LG C3) and Soundbar (Hisense AX3120G) support all formats, why would I want to have the shield process any of it? should I not turn those off to make things run smoother?

Or do I have it backwards with matching content audio resolution and I should leave it enabled?

What about dolby audio processing in general, if the devices support it, do I need it on, do I lose/gain what from having it on/off etc?

 

Thank you.

nvidia itself has said that the dolby processing feature is for one purpose: to convert dolby plus to dolby for devices that can't natively decode dolby plus and need it done for them. this is the best description of it that I've seen:

I think you are getting confused by how nVidia (and others) phrase this.

Dolby audio processing ENABLED means, let the Shield device handle it and decode the Dolby surround sound

Dolby audio processing DISABLED means, ignore the audio format (basically) and let another device down the chain handle it (if you use a AVR, soundbar, etc)

So the phrasing "enable Dolby processing to get surround sound" is kind of accurate. But i understand that it can be confusing.

TL;DR If you use a AVR or other device behind the Shield which you want to handle the audio, disable it. If any device behind the Shield is not able to handle Dolby audio, then enable it.

Maybe nVidia could change the phrasing to something like when its disabled "Enable to process Dolby audio by Shield" and when its enabled to "Disable to let Dolby audio be handled by another connected device"

source: https://www.reddit.com/r/ShieldAndroidTV/comments/vjy6ls/comment/idmw0gl/

Here's another reply directly from nvidia:

Over the years with passthrough (before Dolby processing in the 2019 SHIELDs), we've had a number of users complain when they are playing a 5.1+ title and they pause/play it, they lose the first second or two of sound. This is becasue with passthrough, the recevier is being switched between DD and stereo and that switch causes gaps in the audio.

Netflix has apparently had a lot of users complain about this as well and as such they've designed the netflix app to require Dolbys MS12 stack if you want ATMOS. The main reason for this is in the netflix app with that stack, they keep the recevier in DD mode so there is never any lost audio.
So, this is one othe major benefits of this stack. The stack can also possibly cause av sync to be better since there is finer control than with passthrough. One of the downsides with the stack in Netflix is Netflix requires us advertise stereo shows as 5.1 by stuffing the channels with empty data. This is to avoid the switching between modes which causes the gaps, but the downside is since yoru recevier see's it as DD, you can't enable Dolby pro logic or the other receiver converting features. We've been working with netflix to figure out how to address this but don't have a good solution yet. Disabling Dolby Processing works around this in the meantime in exchange for gaps in the audio as the modes switch.

Our goal for the entire SHIELD was to run it in the MS12 stack. One big problem we ran into with the current version is the latency of the Dolby stack is high, hundreds of ms high, enought that when you navigate menus, the lag feels terrible if it's enabled. This is one of the reasons Netflix has no clicks as you navigate the UI and also for this reason when SHIELD goes back to the home screen, we bypass the MS12 codec which causes a blip in audio but avoids the latency issue.

Becaue of the issues above, there are a few reasons to disable the MS12 stack but disabling it has it's tradeoffs as well, like gaps in the audio as you play/pause/start new shows.

We're working with Dolby to someday get a low latency version of the stack that we can leave on everywhere to have a smooth experience across the entire device without any audio drops as transitioning and without noticable latency that makes clicks feel sluggish.

source: https://www.nvidia.com/en-us/geforce/forums/shield-tv/9/380402/dolby-audio-processing-enable-or-disable/2736774/