Getting the best out of my setup

ytgti

Active Member
So I've just recently upgraded to a Bravia XH95 and Sony STR DH790 (standard 5.1 setup), I've got PS5 (and PS3 & 2 and PC) hooked up to the AVR via HDMI (all 2.1 compliant), then the AVR to TV via HDMI 3 (eARC). IS that correct?

I watch BD/4K UHD discs on PS5, and use the TVs apps like Netflix, Prime and Disney for streaming. Both TV and PS5 are set to PCM, which as I understand is uncompressed sound.

As of last night (and im still a bit confused by this) I thought PCM was better, and say if I was watching a BD/4K UHD I though if it was set to Bitstream id only get DTS, and if I was PCM I would get the full uncompressed DTS MA. But I dont think thats true now and I'll get DTS MA regardless just in a completely different way? I also read that if I wanted Atoms (with the extra speakers which I'm contemplating soon) the only ways is via Bitstream?

So what should my TV and PS5 be set to output given my setup and getting the best out of them?
 
D

Deleted member 39241

Guest
If you use PCM that means that the source is decoding the audio, and sending it to the amp as 5.1.

If you select bitstream, that means the source is sending the audio to the amp in its original format, eg Dolby True HD or DTS HD MA, and the amp is decoding it.

The source will not be able to decode the Atmos metadata, so you need to bitstream that to the amp to get Atmos.
 

gibbsy

Moderator
Any source coming into the AV amp needs to be bitstream. Netflix and Prime both use the Dolby Digital Plus format to carry any Atmos metadata. Check your TV's settings and change to either bitstream or Dolby whichever is on the audio settings. You will not get DD+ via PCM.
 

gibbsy

Moderator
Why is that then? So what is the actual point in PCM?
PCM does not carry Atmos information except for Dolby Mat which does use PCM, Apple TV. PCM is the original digital transport and is still widely used today but usually for stereo applications as it is uncompressed. TV manufacturers cover both formats as both PCM and bitstream for Dolby Digital are available for consumers.
 

ytgti

Active Member
PCM does not carry Atmos information except for Dolby Mat which does use PCM, Apple TV. PCM is the original digital transport and is still widely used today but usually for stereo applications as it is uncompressed. TV manufacturers cover both formats as both PCM and bitstream for Dolby Digital are available for consumers.

Oh I get you now. So even tho I'm not setup for Atmos i should be using Bitstream?
 

gibbsy

Moderator
Oh I get you now. So even tho I'm not setup for Atmos i should be using Bitstream?
Yes. Dolby Digital 5.1 can only be passed using bitstream. Even more important when using a blu ray player as only bitstream can carry HD audio such as Dolby TrueHD and DTS-HD MA.
 

ytgti

Active Member
Yes. Dolby Digital 5.1 can only be passed using bitstream. Even more important when using a blu ray player as only bitstream can carry HD audio such as Dolby TrueHD and DTS-HD MA.

So all this time what sound was i getting via PCM from the likes of Bluray when i thought it was MA or TrueHD?

This has totally opened my eyes how I've thought of it differently. But i was convinced PCM was better from searches id done. I think back when HDMI was taking over fron optical for sound, PCM was recommended for HDMI, bitstream for optical so I've stuck with it ever since.
 

gibbsy

Moderator
So all this time what sound was i getting via PCM from the likes of Bluray when i thought it was MA or TrueHD?

This has totally opened my eyes how I've thought of it differently. But i was convinced PCM was better from searches id done. I think back when HDMI was taking over fron optical for sound, PCM was recommended for HDMI, bitstream for optical so I've stuck with it ever since.
If you have been using PCM then the maximum that can be sent via optical is two channel stereo. That is the maximum because it is uncompressed. PCM is the signal used on CD players because of that uncompressed quality. Even though it is compressed Dolby Digital 5.1 will give more information and better direction to the connected speakers once it is converted by the receiver even over optical but for two channel stereo PCM is better.
 
Last edited:

dante01

Distinguished Member
You may find this article of interest:

The only real difference is which device is doing the decoding. The devices in question will be using the exact same codecs to achieve this. The resulting PCM data is only ever as good as the formatted audio it was deprived from and you'll not get data that the original encoding wasn't encoded with by decoding it at source and then streaming it as PCM data.

You'd also lose any Atmos metadata if decoding the audio at source as opposed to bitstreaming the formatted audio the Atmos metafata id packaged with. The only exceptions to this will be if using an Apple TV 4K, an XBox or a Windows PC. THese use something known as Dolby MAT to output Atmos and this allows the Atmos metadata to be streamed with multichannel PCM data.

PCM can potentially be of a higher quality, but only if the audio was supplied as higher quality PCM. This is not often the case given the fact that PCM is uncompressed data and therefore requires more storage space and greater bandwidth to convey than compressed lossl;ess HD formats such as DTS-HD Master Audio or Dolby TrueHD. THe potential for netter quality is that great anyway, hence why most content will be supplied using the compressed formats as opposed to the uncompressed PCM option.

Note that if the source material was original encoded and supplied as PCM then you'd still get PCM if bitstreaming.
 
Last edited:

ytgti

Active Member
If you have been using PCM then the maximum that can be sent via optical is two channel stereo. That is the maximum because it is uncompressed. PCM is the signal used on CD players because of that uncompressed quality. Even though it is compressed Dolby Digital 5.1 will give more information and better direction to the connected speakers once it is converted by the receiver even over optical but for two channel stereo PCM is better.

Yeah understand it would be 2 channel via optical, but i haven't used one in years it's all through HDMI. It always sounded as good when i compared to bitstream so who knows.

But since this topic I've changed all sources to Bitstream and watched Interstellar 4K UHD last night and it was nice to see it say DTS HD MA rather than PCM as it did often make me question what i was actually hearing.
 

gibbsy

Moderator
But since this topic I've changed all sources to Bitstream and watched Interstellar 4K UHD last night and it was nice to see it say DTS HD MA rather than PCM as it did often make me question what i was actually hearing.
The HD audio is superior to the PCM. Interstellar has a wonderful soundtrack and is one of my favourite films. Play it loud. :)
 

ytgti

Active Member
As loud as I can get away with anyway lol. Bit yeah it an ad and visual treat. I watch it to death on Bluray and i will on 4K. The score is amazing its hard not to have it loud, especially the docking sequence that gets rewound a few times lol
 

The latest video from AVForums

LG G1 OLED Evo TV and SVS SB-1000 Pro subwoofer reviews, Samsung OLED rumours and more...
Subscribe to our YouTube channel

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom