How to Match Dolby and PCM Audio Levels on NVIDIA Shield

On an NVIDIA Shield, moving from a film with a Dolby soundtrack to an app, menu or stream that outputs PCM can cause a sudden jump in volume. The Shield includes an option to match Dolby and PCM audio levels so you don't have to adjust the volume each time the format changes. This guide explains what the option does, how to turn it on and how to confirm it is working on your setup.

The mismatch has a technical cause. Dolby Digital and Dolby Digital Plus streams carry dialogue normalization metadata that tells the decoder to play the soundtrack at a reference loudness, which often means turning it down. PCM audio, used for system sounds, many apps and stereo streams, carries no such instruction, so at the same volume setting it frequently sounds louder. The Shield cannot change the loudness of a Dolby bitstream it passes through untouched, so level matching generally works by bringing PCM output closer to the Dolby level.

Before you start

• Update the Shield to the latest available software version. The name and position of audio options can differ between versions.
• Note how the Shield connects to your output device: directly to a TV, to a soundbar, or to an AV receiver, and whether the link uses HDMI ARC or eARC.
• Check how the Shield handles surround formats. If it passes Dolby audio through as a bitstream, your TV, soundbar or receiver does the decoding. If the Shield decodes everything to PCM itself, the matching option may have little or no audible effect.
• Write down your current Shield sound settings and the volume and processing modes on your TV or receiver so you can return to them later.
• Prepare two test sources: something you know plays in Dolby, and something that plays as PCM, such as the Shield's own interface sounds or a stereo music app.
• The option is a playback setting on the Shield itself. Turning it on does not require signing in to an online service.

Step-by-step instructions

• 1. Open Settings from the gear icon on the Shield home screen.
• 2. Open the sound settings. On recent software versions these are usually found under Device Preferences, then Sound. If your menu looks different, look for the section that contains the surround sound and audio format options.
• 3. Find the option for matching Dolby and PCM audio levels. The exact label can vary by version, so look for wording that mentions Dolby, PCM and levels or volume.
• 4. Turn the option on. Leave your other surround sound and format settings unchanged for now so you can judge the effect of this one change.
• 5. Play your Dolby test source and set a comfortable volume on your TV, soundbar or receiver.
• 6. Without touching the volume, switch to your PCM test source and compare how loud it sounds.
• 7. If you prefer the previous behaviour, return to the same menu and turn the option off. No other settings are changed by this step.

Keep in mind that your receiver or soundbar may apply its own processing, such as night mode, dynamic range compression or automatic volume leveling. These features also change perceived loudness, so turn them off temporarily while you compare, or at least keep them the same for both sources.

Check the output

• Confirm which format is actually arriving. Many AV receivers and some soundbars show the incoming signal type on their display or in an info menu. Make sure your Dolby test really arrives as Dolby and your PCM test arrives as PCM.
• Compare similar material. Dialogue scenes are easier to judge than music or action, because dialogue normalization targets speech level.
• Listen in a quiet room. Background noise makes small level differences hard to hear.
• Expect closer levels, not identical ones. Each soundtrack is mixed and mastered differently, so some variation between titles and apps is normal even with matching enabled.
• The option affects loudness only. It does not change the audio format, sample rate or channel layout being sent to your output device.

Common problems and next steps

The option is missing. Install any pending Shield software update and look again in the sound settings. Availability can depend on the software version and on your audio output configuration, so if it still doesn't appear, check the release notes for your version before assuming the device supports it.

Nothing changes after turning it on. The Shield may already be decoding all audio to PCM, in which case there is no Dolby bitstream for the PCM level to be matched against. It is also possible that your TV or receiver is applying its own leveling that hides the difference. Check the incoming format on your output device and compare again with its processing modes turned off.

PCM sound is now too quiet. That is the expected trade-off when PCM is brought down toward the Dolby level. Raise the overall volume slightly, or turn the option off if you mostly use PCM sources. Some receivers also offer a per-input level trim, which can help if the Shield shares a receiver with other devices.

One app still jumps in volume. Some apps decode audio themselves or apply their own normalization, and some content is simply mastered louder than average. In these cases the difference comes from the source rather than the Shield setting. If the jumps remain a problem across many sources, try your receiver's or soundbar's own volume leveling or night mode as an additional layer, and remember that these modes also reduce dynamic range.