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Discussion Starter · #1 ·
Hey Everyone,


I ahve had my Home Theater for about a year and am enjoying it.


I have researched this question a lot and still seem wanting for a clear answer.


my current set up is.


HK AVR 247

PS3

52" Samsung B550


Experimentation seems to lean towards LPCM being better than bitstream but I would still like to hear which is better in theory rather than my untrained ear.


Thanks all.
 

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With your setup, you are limited to Linear PCM for lossless 5.1/7.1 audio. Just sit back and enjoy. I have a HK 745 and PS3 and enjoy 5.1 PCM.
 

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The only difference you may encounter is a slight variation in levels, maybe. A receiver and a BD player should do an equal job of converting the lossless compressed audio to PCM. It's kind of like unzipping a compressed file on your computer... It doesn't matter if you use WinZIP, 7-Zip, WinRAR, etc. You're going to get the same results. It either works or it doesn't. If it doesn't work, you're not going to have anything usable and it will be obvious that something is broken.
 

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Quote:
Originally Posted by Kal Rubinson /forum/post/18268683


In theory, there is no difference. In practice, ask Yogi.

Yogi Berra or Yogi Bear?
 

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Quote:
Originally Posted by bommai /forum/post/18268681


With your setup, you are limited to Linear PCM for lossless 5.1/7.1 audio.

Which PS3 model do you have, skerr1? The current "slim" models bitstream HD audio.
 

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Discussion Starter · #8 ·
I got mine at used at Gamestop almost a year ago so no slim or HD bitstreaming for me.


I bought me receiver refurbed on ebay and am really ahppy with it.


I am going to just leave it on LPCM as that seem to have more depth and calrity to the sound. There also seems to be more lfe activity which I read somewhere that lpcm boosts this up 10d.


Wish I would have known at the time this receiver does not handle the blu ray codecs, though.


I may save up and get one. But if so is it a waste to not get 2 additonal speakers in addition to my 5.1 speakers if I upgrade to a receiver that can handle DTS HD and Dolby TrueHD?


Thanks all. I think I have a good handle on it now.
 

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Quote:
Originally Posted by skerr1 /forum/post/18269735


I am going to just leave it on LPCM as that seem to have more depth and calrity to the sound. There also seems to be more lfe activity which I read somewhere that lpcm boosts this up 10d.

The 10db boost for LFE happens with both PCM and encoded audio formats. There's no advantage to PCM on that score. LFE is boosted by 10db because it is recorded 10db low to prevent clipping during transmission.

Quote:
Wish I would have known at the time this receiver does not handle the blu ray codecs, though.

With the PS3 doing the decoding, there's no need for the AVR to process the HD codecs. You get the same PCM either way. And, a new AVR would not matter because older PS3s cannot bitstream TrueHD or dts-MA. You would need a new player along with a new receiver.

Quote:
I may save up and get one. But if so is it a waste to not get 2 additonal speakers in addition to my 5.1 speakers if I upgrade to a receiver that can handle DTS HD and Dolby TrueHD?

Again, this is not an issue of bitstreaming HD codecs to your receiver. Your PS3 can decode 7.1 sources and output all eight channels as PCM. However, it appears that your HK 247 is limited to accepting 5.1 over HDMI. You can then apply matrix processing in your receiver to produce rear channel audio. Very few Blu-rays have 7.1 soundtracks, btw. Movies are mixed as 5.1 for theatrical release and most are released on Blu the same way.


Back to your original question - PCM is a high resolution source while bitstreaming from an older PS3 produces a lossy output. Truth be told, the lossy codecs on Blu-ray are encoded at high bitrates and rival lossless in quality. But, the PCM output of your PS3 might be a bit better and would never be worse.
 

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Quote:
Originally Posted by MichaelJHuman /forum/post/18269501


Yogi Berra or Yogi Bear?

The one still alive. I meant Berra but I guess Bear's opinion would be similar.
 

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PCM is not a 'high resolution source'; it is a standard digital format for audio.


Bitstreaming is the compressed 'package' of PCM channels which need decoding/decompressing.


DVD utilises Dolby/DTS lossy codecs for the encoding/decoding as bitstreams.


It is true that bluray discs which use the latter have a higher bit-rate BUT they do not approach HD audio.


Decoding is best chosen by what gives the best results as far as your personal impressions.


Incidentally uncompressed PCM is tops since no decoding occurs at all in the chain; check out Casino Royale, Pirates OT Caribbean trilogy, Kill Bill vols1/2, Ghostrider etc


Also some DVD players boost the subwoofer level by up to 15db but only via the analogue multichannel outputs.
 

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Quote:
Originally Posted by hotpot65 /forum/post/18272399


Incidentally uncompressed PCM is tops since no decoding occurs at all in the chain; check out Casino Royale, Pirates OT Caribbean trilogy, Kill Bill vols1/2, Ghostrider etc

Why would uncompressed PCM be better than losslessly compressed audio? In theory, they would be identical in quality if the losslessly compressed audio was sourced from the same master as the uncompressed PCM?


I agree that DTS/DD on Blu-ray are not lossless, but one listening test showed they they were very high quality. This point is only important if someone is trying to determine if it's worth spending money to go lossless.
 

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Quote:
Originally Posted by MichaelJHuman /forum/post/18272793


Why would uncompressed PCM be better than losslessly compressed audio? In theory, they would be identical in quality if the losslessly compressed audio was sourced from the same master as the uncompressed PCM?

+1...


not just in theory... but in actual real live practice...



some people just can't get past the fact that "lossless is lossless", and an "additional decoding step" (i.e. converting lossless codec back to pcm) has zero effect on the end result...
 

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Quote:
Originally Posted by hotpot65 /forum/post/18272399


PCM is not a 'high resolution source'; it is a standard digital format for audio.

To clarify - with PCM you get the original source instead of a lossy downconversion. I believe you will find that the stereo PCM option on concert DVDs generally provides a higher resolution output than the DD 5.1 or DTS options.

Quote:
It is true that bluray discs which use the latter have a higher bit-rate BUT they do not approach HD audio.

Says you. I beg to differ. This is an interesting read on the subject:

http://www.hemagazine.com/node/Dolby...compressed_PCM

Quote:
Incidentally uncompressed PCM is tops since no decoding occurs at all in the chain; check out Casino Royale, Pirates OT Caribbean trilogy, Kill Bill vols1/2, Ghostrider etc

Again, says you. Please explain how lossless compression such as TrueHD and dts-MA reduce quality when the PCM produced by decompression is identical to the original. Besides, didn't you say, "PCM is not a 'high resolution source'; it is a standard digital format for audio"?
Quote:
Also some DVD players boost the subwoofer level by up to 15db but only via the analogue multichannel outputs.

You're way off base here. But, I'll play along. Care to identify the DVD players that do as you describe?


There's an excellent sticky thread in the Audio Theory forum that explains how LFE is handled. It's pretty much required reading for those who wish understand LFE and bass management.

http://www.avsforum.com/avs-vb/showt...40#post8855640
 

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PCM is not a source as stated. Yes I agree it can be high resolution but it only reflects the resolution of the source material e.g. 16 bit , 24bit etc


I also agree that in theory DTS Master Audio and Dolby TrueHD should be bit for bit like the studio master, but they undergo encoding/compression and decoding/decompression. Such processing may produce a less than perfect likeness; whereas uncompressed bypasses this - I know it shouldn't matter in theory but in practice there can be differences. I have several Eastern blurays which have 7.1 uncompressed, 7.1 DTS HD MA and 7.1 Dolby TrueHD all as alternatives. The uncompressed usually sounds better.


I have played other bluray discs with DD and uncompressed - e.g Casino Royale - and flicked between to compare. No, the DD does not approach the HD audio of the uncompressed.


The 15 db subwoofer issue is mentioned in my Onkyo 606 manual. There is a setting to alter the subwoofer sensitivity through the multichannel analogues to compensate. Also my old Pioneer 747 DVD is such a player.
 

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Quote:
Originally Posted by hotpot65 /forum/post/18274356


PCM is not a source as stated. Yes I agree it can be high resolution but it only reflects the resolution of the source material e.g. 16 bit , 24bit etc

Yes.

Quote:
I also agree that in theory DTS Master Audio and Dolby TrueHD should be bit for bit like the studio master, but they undergo encoding/compression and decoding/decompression. Such processing may produce a less than perfect likeness; whereas uncompressed bypasses this - I know it shouldn't matter in theory but in practice there can be differences. I have several Eastern blurays which have 7.1 uncompressed, 7.1 DTS HD MA and 7.1 Dolby TrueHD all as alternatives. The uncompressed usually sounds better.

This seems to be about how you think things probably work and your own uncontrolled, self-administered tests. Have you run across any data or expert opinion to support your position here?

Quote:
I have played other bluray discs with DD and uncompressed - e.g Casino Royale - and flicked between to compare. No, the DD does not approach the HD audio of the uncompressed.

More of your own home tests. Any reaction to the article I linked?

Quote:
The 15 db subwoofer issue is mentioned in my Onkyo 606 manual. There is a setting to alter the subwoofer sensitivity through the multichannel analogues to compensate.

Yes, the subject is mentioned in Onkyo manuals.


Regardless, I do not understand what point you are trying to make here. The OP made an incorrect claim that PCM has more LFE activity because "I read somewhere that lpcm boosts this up 10d". I pointed out that there's no difference between PCM and encoded sources. Receivers boost LFE for both types of digital audio data. You then made the claim that some DVD players boost the sub for multichannel analog by 15db. I suppose a player or two might do that. It would be wrong and, fortunately, not many make that kind of mistake. But, what does that have to do with what was being discussed?
 

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Quote:
Originally Posted by ccotenj /forum/post/18272806


some people just can't get past the fact that "lossless is lossless", and an "additional decoding step" (i.e. converting lossless codec back to pcm) has zero effect on the end result...
Quote:
Originally Posted by hotpot65 /forum/post/18274356



I also agree that in theory DTS Master Audio and Dolby TrueHD should be bit for bit like the studio master, but they undergo encoding/compression and decoding/decompression. Such processing may produce a less than perfect likeness; whereas uncompressed bypasses this - I know it shouldn't matter in theory but in practice there can be differences. I have several Eastern blurays which have 7.1 uncompressed, 7.1 DTS HD MA and 7.1 Dolby TrueHD all as alternatives. The uncompressed usually sounds better.

at the risk of repeating myself...


lossless is lossless... there's no "may" about it...


i'd bet my entire house and contents thereof vs. a candy bar that you couldn't tell the difference between lpcm and whatever lossless codec you want in a level matched blind test...
 

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Thing is, bitstream does not always work like PCM. Not saying the sound quality differs. But something can differ, as my PS3 tests have shown.
 

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Quote:
Originally Posted by MichaelJHuman /forum/post/18275161


Thing is, bitstream does not always work like PCM. Not saying the sound quality differs. But something can differ, as my PS3 tests have shown.

Sorry, but I'm not familiar with your tests. What did you test and what were the results?
 
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