Linear PCM vs Bitstream

[davidAZ]

Originally Posted by JohnGalt

Well unless you're me in which case setting your PS3 to LPCM results in only 2-channel 48 KHz output. In that case bitstream is far better even if if precludes hearing the uncompressed soundtracks on BD discs.

I've had the same issue. I set the PS3 to PCM with optical cable and went with it... the sound was pretty good, but I found that it was only sending 2 channels at 48 KHz. I tried everything and nothing improved. Finally I switched to bitstream and the sound is true surround and vastly improved.

[MouseRider]

Originally Posted by neckedness

You know, in APOCALYPTO, the menu sound clicks can be heard when set to Linear PCM, but when set to Bitstream, there's no clicks.

Yes, that's because the menu clicks can be inserted into the PCM stream very easily.

To insert the clicks into bitstream mode, the player would have to decode the bitstream, insert the click, then recode the bitstream and send it to you, can be done but I would guess not worth the trouble.

[Disco_And]

Originally Posted by neckedness

So it's best to leave on Bitstream for PCM 5.1? Even though the volume is lower than DD, just turn it up alot more? Thanks for the answer.

yes as long as your using a hdmi cable that way you can have up to 7.1 with the onkyo

Originally Posted by JohnGalt

Well unless you're me in which case setting your PS3 to LPCM results in only 2-channel 48 KHz output. In that case bitstream is far better even if if precludes hearing the uncompressed soundtracks on BD discs.

You only get 2 channel PCM if you’re using the optical lead, change over to hdmi to get 7.1 if your amp has it and reap the rewards

Also I know some people say that Upgrade cables can’t make any difference because it’s all digital? There’s only one answer to that, and it rhymes with “rollocks”.!!! Remember you also send sound though the lead to so better cable = better sound try to get sliver/plated if you can it make all the difference especially when you can here it on an onkyo, but the only real way for you to know is to go to your local Hi-fi store and ask for a demo, you can take your ps3 or use one of there Blu-ray player and then see if you see any difference, I’m sure you will be coming home with some nice new leads

[LembasBread]

Originally Posted by gand41f

DAC = digital-to-analog converter

PCM is also digital, there's no DAC involved.

Actually there is. In the receiver the LPCM hits the DAC goes to the pre-amps and monitor amps out to your monitor speakers. Without a DAC, there's no way to hear and amplify digitally delivered audio.

[LembasBread]

Originally Posted by jcs913

Actually, a high-quality receiver can decode and output codecs better than some players can, especially DTS-ES, like the post before yours stated. The better the DAC in a receiver, the more dynamic range the soundfield will have. When the PS3 decodes it, it only applies what the software in the cell processor tells it to apply. When a better quality BD player decodes the codec, like a Pioneer Elite, it applies more dynamic range to the sound then the standard that the PS3 applies.
It is a big difference in what you get out of the player. There are reasons the players are more money than others. They DO have better video and audio processing. A DTS track is not decoded the same in every player. The bitstreaming of audio is key to a receivers worth.
You are correct, a PCM track is the same whether it comes from the receiver or player. As for the new HD codecs, when the new players come out and can bitstream those codecs, you will hear a different sound from those than you will the PS3 decoding. You are correct, the PS3 will never bitstream those codecs, as the HDMI 1.3 was not really a true 1.3 plug. I do not know why the DTS-HDMA firmware has not hit yet. I am a little worried as to the complexity of the decoding in relation to the PS3's ability to truly decode it. Again, the better the player, the easier it can do things.
Do not get me wrong, I own a PS3 and think it is the best player on the market. But if the format is moving forward, the audio needs to also. That is why all these new players are coming out. The PS3's cell can only do so much. Remeber, it is there for many other things, besides playing BD movies. Be careful with your cynicism with the 'marketing' comment. Any audiophile will tell you that the better the player/receiver, the more you will get out of it.

Decoding is decoding is decoding. There's no "better DTS decoding" in players or receivers. The real audio difference comes with the quality of the DSP's or DAC's in the players/receivers. While I agree that high end receivers usually will have better DAC's and pre-amps - which is where the character of the audio is shaped - decoding within the player and sending it out as LPCM will have absolutely no difference in the audio quality than having it bitstreamed and letting the receiver do the decoding. In fact it's safer to send the audio as LPCM and have the receiver set to Direct or Pure mode to bypass many unnecessary DSP's that manufacturers like to add to these machines. As I've said, the Onkyo TX-SR605 inexplicably boosts all Dolby audio tracks by +3dB compared to sending the audio as LPCM from both the PS3 and my Denon DVD-756 DVD player.

It's the players that have multi-channel analog outputs that would have percievable differences in audio as they're doing all the DAC-ing and pre-amping within the player (plus extra DSP's if you're using bass management). It's then that you might be matching cheap DAC/pre-amps with high end amps or vice-versa that would cause disparity in audio.

Sending audio as LPCM from the PS3 should sound exactly the same as LPCM audio from a Pioneer Elite BD player running through the same pre/pro or receiver.

[MouseRider]

Originally Posted by LembasBread

Actually there is. In the receiver the LPCM hits the DAC goes to the pre-amps and monitor amps out to your monitor speakers. Without a DAC, there's no way to hear and amplify digitally delivered audio.

I believe what Gand41f was trying to say in responding to jcs913 is that decoding from a bitstream to PCM does not involve DACs as at that point, everything is still in the digital domain.

So if you assume that the implementation of bitstream decoding chips are all standardized, the price point or brand of the player, receiver or processor doing the decoding should not affect the quality of the resulting PCM stream.

Compare that with going from PCM to sound which will involve a DAC, as you've correctly pointed out, there might be more factors to consider as to quality because based on the quality of the DACs and the quality of the analog stage components.

UPDATE: just saw your last post which says the same thing, we must have hit submit at the same time

[JohnGalt]

Originally Posted by Disco_And

You only get 2 channel PCM if you’re using the optical lead, change over to hdmi to get 7.1 if your amp has it and reap the rewards

I don't think I even own an optical cable, been using HDMI since day one. LPCM always results in 2 channel 48 KHz output from my PS3. It's not the receiver because the PS3's own on-screen display confirms the signal info shown by the receiver. I tried to turn off all of the 2-channel output options in the PS3's menus but naturally it won't allow me to disable the lowest quality settings.

[crackinhedz]

Originally Posted by JohnGalt

I don't think I even own an optical cable, been using HDMI since day one. LPCM always results in 2 channel 48 KHz output from my PS3. It's not the receiver because the PS3's own on-screen display confirms the signal info shown by the receiver. I tried to turn off all of the 2-channel output options in the PS3's menus but naturally it won't allow me to disable the lowest quality settings.

which receiver are you using? (some receivers do not process HDMI audio and could be reason youre getting 2.0 PCM)

[JohnGalt]

I'm using a Yamaha RX-V3800. It's not an HDMI audio processing problem, it decodes multi-channel audio over HDMI just fine ... so long as it *is* decoding the audio (i.e., the PS3 is set to 'bitstream' rather than 'LPCM'). The problem occurs when the PS3 is allowed to decode the audio, it will not output anything other than 2-channel sound as confirmed by the PS3's own OSD and by the Yamaha's signal information function. It may well be pilot error but I'm leaning towards it being a glitch with the PS3 that isn't allowing me to force multi-channel output via LPCM.

[Stormyhog]

I would like to know what should the audio settings be on the PS3 using HDMI when not using a sound system? Should I use the low 2 channel setting or should I use the higher 2 channel settings? Thanks.

[neckedness]

If you're not using a sound system, the settings shouldn't matter right? Is it going to the TV? Then both settings will be heard in 2.0 stereo, I think.

[Stormyhog]

Originally Posted by neckedness

If you're not using a sound system, the settings shouldn't matter right? Is it going to the TV? Then both settings will be heard in 2.0 stereo, I think.

I am just using the tv speakers and was wondering what 2 channel options should be be checked marked the low settings or higher settings?

[gand41f]

Originally Posted by MouseRider

I believe what Gand41f was trying to say in responding to jcs913 is that decoding from a bitstream to PCM does not involve DACs as at that point, everything is still in the digital domain.

Yes. Sorry for not quoting enough context to make it clear enough. My bad.

enjoy
gandalf

[gand41f]

Originally Posted by LembasBread

As I've said, the Onkyo TX-SR605 inexplicably boosts all Dolby audio tracks by +3dB compared to sending the audio as LPCM from both the PS3 and my Denon DVD-756 DVD player.

My Onkyo HT-R330 does it too. It is really rather annoying when I'm trying to compare DD bitstream to LPCM.

enjoy
gandalf

[gand41f]

Originally Posted by davidAZ

I've had the same issue. I set the PS3 to PCM with optical cable and went with it... the sound was pretty good, but I found that it was only sending 2 channels at 48 KHz. I tried everything and nothing improved. Finally I switched to bitstream and the sound is true surround and vastly improved.

I don't know. I'm in the same boat with you (no HDMI input to receiver) but to me 2-channel PCM converted to surround by my receiver's "Neo 6 Cinema" (whatever that means) sounds better than DD5.1. Sure, you lose some surround effects but most movies don't have that much distinct signals on the back speakers anyway, and the additional clarity of lossless audio more than makes up for it.

enjoy
gandalf

[jcs913]

Originally Posted by gand41f

Yes. Sorry for not quoting enough context to make it clear enough. My bad.

enjoy
gandalf

What about DTS-ES or DDEX tracks. Does your PS3 apply that rear surround 6th speaker when it sends it out LPCM?

[LembasBread]

Originally Posted by jcs913

What about DTS-ES or DDEX tracks. Does your PS3 apply that rear surround 6th speaker when it sends it out LPCM?

Well, Dolby Digital EX is still only 5.1 with metadata flags to tell the receiver to matrix out the center-surround. But, with DTS-ES, the discrete 6.1 track is decoded as the core 5.1 only. This is one of very few reasons to bitstream audio from the PS3.

[jcs913]

Originally Posted by LembasBread

Well, Dolby Digital EX is still only 5.1 with metadata flags to tell the receiver to matrix out the center-surround. But, with DTS-ES, the discrete 6.1 track is decoded as the core 5.1 only. This is one of very few reasons to bitstream audio from the PS3.

But this my thought process. Why lose anything from the original on ANY track. There are too many beginners to the format with PS3 usage. People need to understand that the PCM from their receivers is the PS3 decoding everything. People will lose some, albeit not a large amount, of the original audio from certain BD's and DVD's. Pan's Labyrinth (SD-DVD) and Punisher (BD) has an excellent DTS-ES track. But if the PS3 decodes it, you lose out. Why not bitstream all tracks out, if you have a capable receiver over HDMI. The only problem is with TrueHD, which needs to be decoded and sent LPCM, which most people seem to know anyway. I have not heard any 'good' reasons why not too, if you have a capable receiver. Enlighten me.

[LembasBread]

Well, you certainly can bitstream or LPCM the audio, but once PiP comes along the audio from the PiP and from the movie have to be mixed within the player itself.

Second, as I've stated, with today's off the shelf receivers, manufacturers like to add a lot of DSP's that mess around with the quality of the audio. The less DSP's and DAC/ADC's there are in the signal path, the more pure the audio is.

On the rare occasion that you have a 6.1 DTS-ES track (which are very rare when compared to 5.1 DTS tracks) and if you even have a DTS-ES decoder let alone the extra center-surround speaker, then bitstream is necessary on the PS3. But, with the whole confusion of putting it on LPCM or bitstream, most newbies don't even know what that means to begin with let alone what DTS-ES is and how to properly set up the 6.1 configuration. They won't be missing out on that discrete center surround channel anyway. Plus, most receivers have DSP's that matrix in the back surround channels effectively adding that center surround channel from a DTS-ES track that comes in as 5.1 LPCM.

So, if you're a purist who needs that discrete DTS-ES back surround channel, then chances are you know what's the dealy-o and you'll know the difference between bitstream and LPCM and the benefits of each.

If you're player doesn't bitstream (i.e. the PS3) it's safest to leave everything as LPCM to get the full benefit of all the audio it's capable of decoding like Dolby TrueHD and hopefully DTS-HD MA soon.

[jcs913]

Originally Posted by LembasBread

Well, you certainly can bitstream or LPCM the audio, but once PiP comes along the audio from the PiP and from the movie have to be mixed within the player itself.

Second, as I've stated, with today's off the shelf receivers, manufacturers like to add a lot of DSP's that mess around with the quality of the audio. The less DSP's and DAC/ADC's there are in the signal path, the more pure the audio is.

On the rare occasion that you have a 6.1 DTS-ES track (which are very rare when compared to 5.1 DTS tracks) and if you even have a DTS-ES decoder let alone the extra center-surround speaker, then bitstream is necessary on the PS3. But, with the whole confusion of putting it on LPCM or bitstream, most newbies don't even know what that means to begin with let alone what DTS-ES is and how to properly set up the 6.1 configuration. They won't be missing out on that discrete center surround channel anyway. Plus, most receivers have DSP's that matrix in the back surround channels effectively adding that center surround channel from a DTS-ES track that comes in as 5.1 LPCM.

So, if you're a purist who needs that discrete DTS-ES back surround channel, then chances are you know what's the dealy-o and you'll know the difference between bitstream and LPCM and the benefits of each.

If you're player doesn't bitstream (i.e. the PS3) it's safest to leave everything as LPCM to get the full benefit of all the audio it's capable of decoding like Dolby TrueHD and hopefully DTS-HD MA soon.

Your points are very well taken and true. I am not an expert in the PS3's ability to decode, but isn't it true that during the decoding process, players apply different types of DSP's to the tracks? And doesn't the PS3 decode using the cell processor, not a dedicated decoder?