PCM Has No Bass

[Spottedfeather]

I was having trouble hearing a certain scene of dialogue. I was told to change bitstream to PCM. When I did, the dialogue WAS easier to hear. The problem is that if I use PCM, there is practically no bass.

For example, during the intro of Jurassic Park, when the titles appear, there is a huge deep boom noise. With bitstream, you can almost feel the boom in your chest. But if I run that scene with PCM, there's no bass at all. Going from bitstream to PCM is the only setting change I made...other than turning off BD secondary audio.

Any ideas why this is happening ? Should I turn the subwoofer up ? Currently it's set at +2 on mode settings, while it's set at, I think, 0 on the setup done with the microphone. I could be wrong about these settings, though

 

[lovinthehd]

Need more info about your source, gear and settings involved but at a guess your PCM is 2.0 channel, rather than multich PCM (LPCM), and has no LFE.

 

[Sawtaytoes]

Interesting. I'm noticing a similar issue.

First, I think you should be using bitstream audio (which supports PCM too) rather than PCM audio output.

My Similar Issue

I have 2-channel PCM files on shows I've imported from Japan. I rip the discs and add subtitles, but I've found there's no bass in the playback like there is on my PC.

Switching to the AC3 track, it's like the sound opened up. Instead of sounding like a 64kbps MP3 with no bass, it sounded like a regular-quality audio track with tons of bass and sound that had much more atmosphere when upmixed.

The only thing weird about the PCM track is it's 24-bit 48kHz. I'm using Plex, and this page says that's not supported even if the Shield itself supports this audio format:

I'm thinking your player might have the same issue. It might be converting 24-bit Dolby TrueHD or DTS-HD MA to 16-bit PCM. Whatever it's doing, it's removing the bass. If you listen closely, it might also be making the audio sound very low-bitrate-MP3 compressed.

My Gear

• I have HDMI passthrough enabled on both the Shield and in Plex.
• I disabled the PCM to Dolby Digital conversion that the Shield has on by default.
• My receiver is the Marantz AV 10 and my TV is the LG G2 OLED.
• My connections are Shield → Receiver → TV.
• I have the Dolby Surround upmixer enabled; not Direct, but it's the same regardless of what setting I try.
• I made an AVSForum post with more details (including screenshots) here: PCM audio with no bass on NVIDIA Shield & Plex? | AVS Forum

I thought it might be a Plex issue, and it might be, but I'm also wondering if it's an AVR issue where the Marantz AV 10 simply doesn't support bass output with PCM audio.