Axiom Home Page Forums General Discussion Home Theater Question about PCM lossless and optical cable

Hi!

I recently added a vp100 v2 to my pair of M3 (next purchase will be pair of QS4 next year or sooner), and I started this week to enjoy better overall sound from movies.

I just discovered that optical cables can't handle the bandwith of PCM lossless 5.1 soundtrack from my PS3 and hd-dvd player. Only hdmi cables can do the job (there's lot of information about that on the web). And my receiver do not have hdmi connector for sound. I know that the logical solution would be to buy a new receiver for optimal results, but I want your opinion/advice on this.

Based on my actual configuration, it is better to:
1- Go with PCM lossless sound on 2 channels and let the receiver do processing with Dolby Pro Logic?
OR
2- Go with the regular Dolby Digital 5.1?

Actually in 2.1, the sound seems better with PCM processed with Dolby Pro Logic. On the other hand, when I'll get surround speakers, I think that the Dolby Digital will do a better job for surround sound.

Is that a logical thought?

Thanks for your opinion!

PS: There's no bandwith problem with optical cable for Dolby TrueHD and DTS-HD soundtracks. Just too bad that Black Hawk Down blu ray only have high def soundtrack in PCM lossless.

Patrick

I didn't think the PS3 downmixed and matrixed the multi-channel PCM when being output over the optical link. But if you're hearing clear dialog (the center channel), then it must at least downmix.

You're right, a new receiver would be the "best" solution, but until I got mine I was very happy with the optical outputting Dolby Digital or DTS. Honestly, I was a little disappointed with how little difference I heard after the upgrade. But getting the two extra surround channels with 7.1 which prompted me to buy the QS8s, was an ear opening experience.

While technically, there may be enough bandwidth on a S/PDIF link for Dolby TrueHD or DTS-HD Master Audio, that is not what you get. When picking one of the lossless formats, the PS3 selects the "core" lossy portion of that track and sends that to the optical port.

The way you should have your PS3 configured is for optical output with bitstream. Then pick the highest quality audio track on the disc which is not PCM. If a Blu-ray has both Dolby Digital 5.1 and DTS-HD Master Audio, pick the later. The Core of MA is a 1.5 Mbps DTS track, which will top Dolby's lossy offering.

Wait, you can send True-HD over optical cables? But that's in 'unpacked' mode right? I don't think my Denon would know what to do with bitstreamed True-HD since it came out before those formats did. I wonder what it would do with it?

No, what Chris indicated was that the lossy content(which again, may not be audibly distinguishable)would be transmitted over the optical or coaxial digital connection.

Incidentally, the term "lossless" has no application to a PCM track, since PCM on CDs or other discs has no data compression, lossy or lossless.

What I was trying to say without saying it, is that quality optical and coax (for reference see the telco world where 45 Mbps is routinely transmitted over RG-6 coax) are more than capable of handing the bandwidth required for multichannel, lossless audio. The truth is the studios did not want to update the S/PDIF specification, an unencrypted interface, to carry the new codecs. So it was mandated that they only be sent over HDMI.

So yeah, any player will only send the lossy "core" of the lossless codecs to the optical interface.

Interesting information about that decision.

And thx a lot for your help.
My PS3 was in fact configured for bitstream at start. But because of Black Hawk Down movie soundtracks, I was trying different ways to get the better of this and from my actual equipment.

Got over 50 high def movies, but only 2 of them have PCM 5.1 soundtrack. At least they also have DD 5.1 !

Those wiley ol studio's and their tricks. I wonder just how long it's going to take them to render 1080p 'yesterdays news' and double or triple the resolution? I mean after all house hold tv's went a whopping... what, 50 years? Before they finally upped standard resolution first to 1080i and now 1080p. But my guess is in todays ever changing digital world 1080p isn't going to stick around as 'King of the Hill' for that long. I give it a good ten year run max before 'Blu-squared-Ray takes over, or something similar.

Can you imagine the day our grandchild says, "grampa what's this"? And we say, "oh that's a Blu-Ray disc. We used to watch movies from these". And they giggle and say, "wow, you really are old grampa".

That day is coming, believe it or not.

It could also come to a point where everything collapses, and it will be a long time before another civilization surpasses the technology that we take for granted, but I'm hoping it goes the way you're saying.

Oh I have no doubt about that at all. I'm hoping our grandchildren don't see it, but rest assured we will not be the last civilization to rule this world. The dinosaurs had a much longer run then we'll ever enjoy. We simply gobble up way too much of the earths resources to make it millions of years. Our species have had a good foothold as the top of the food chain for less than 35,000 years and already we're nearly at the breaking point as far as being able to sustain ourselves... how are we supposed to make it another 15 or 20 million years?

And the earth is still young. It has enough years left in her to see at least another 4 or 5 civilizations rise and fall before it's all over. We will not be here when the sun explodes. There's not a doubt in my mind about that. If we live to see the next ice age, it'll do us in almost assuredly. Or a meteor. Nuclear war. AIDS. Take your pick.

By reaching out to the stars......

No I don't mean space exploration and habitation, I mean the other stars. Tom Cruise says he is the only one who can save us.

Wait.... We're doooomed!

Wow, except for Murph's new avatar, you guys are really a buzzkill.

Oh, good point. The bees are dying.

Cheer up, Emo kid.

I suppose as long as we have Murph's new avatar to see us through, it'll be fine.

I'm guessing the next gen evolution for tv will be 3D based, like holographic imaging.

I'm hoping to see 7 of 9 in 3D imaging.

Hey I never said WE were gonna die, just our species. Heck I'm gonna live my 80 or so years to the fullest!

[quote=chesserooI'm guessing the next gen evolution for tv will be 3D based, like holographic imaging.[/quote]
Except they will find a way to disable the 3d every 5 minutes unless you feed another fiver into the slot in you'r studio owned 3D wonder machine.

I don't know that 3D will be next, but I definately think our grandchildren will have holographic tv like devices. One thing that I think I can see coming over the horizon is the day when you won't even buy a disc. Like the new Samsung I just bought, you can watch movies right over the internet with it. I can see a day when that's how it will be. You won't buy an actual disc, you'll just buy the rights to watch a particular movie whenever you want.

It's going to be a long time before I'm comfortable with download-only purchases. When I have a physical copy, my options for what to do with it seem to be much greater. When it's just downloaded data, it can be problematic to share with other people, and I have to rely on the company I purchased from not going out of business and leaving me high and dry when something happens to my downloaded copy. And it seems like we're still too far away from everyone having internet speeds that would allow this kind of delivery for the cutting-edge in quality. If this is the future that the market forces on me, I'm not sure I'll be too thrilled.

You hit the nail on the head, they don't want you to be able to share it as easily. Plus think of all the costs they will cut... no physical inventory, no shipping costs, no damage product or returns to deal with, no theft, no loss due to fire or other natural disasters to worry about. Remember, the future is all about their profitability, not your convenience!

Yeah, I can see the upside for the companies, but consumers still dictate what succeeds, which is why it's discouraging to see downloads making headway.

It's not like BD is much better--yeah, they can't remove it from you, but they certainly lock down features like crazy--and I'm not just talking about copy restrictions. What about component video? They completely killed it. It's definitely good enough for 720p (possibly 1080i/p?), but it's simply not allowed. Why do electronics companies let content creators dictate how their products work?

Even with BD's restrictions, I can still share them with people, and I don't have to rely on someone's remote storage of my content. That being said, you're right that nixing component as a viable output option was just stupid. As for why electronics companies bow to content creators... I imagine it's because the content is why people are buying the electronics in the first place. If they're not on board, good luck getting the devices to sell. Right? Maybe. I'm getting a little tired in the brain.

Same here. I agree. Look what happened recently with Amazon's Kindle. They pulled a book and remotely deleted the title from hundreds, if not thousands, of customers completely without warning. Even with the refund they issues that would really piss me off. It became a PR nightmare for them.

Given the behavior of the movie studios, I wouldn't put it past them to decide to suddenly change the terms of the agreement and remotely expire or delete titles unannounced and as they saw fit.

In other words, digital downloads with DRM leave the big-brother factor in play. I don't mind that on its own, but I do mind it being in the hands of the movies studios - which to date have repeatedly shown fairly poor greed driven judgment when it comes to dealing with consumers.

To a certain extent maybe. They might give consumers the choice between two new formats and let us decide which of those formats succeeds... like introducing VHS & beta, and we chose VHS. Or recently giving us HDDVD & Blu-Ray, we chose Blu-Ray.

But when they really want to steer away from something they don't give us a whole lot of say in the matter. For instance I don't think the general public really wanted vinyl to disappear, there is still a strong vinyl following today. But they moved away from it and simply stopped producing records. Then there is the recent switch to digital television... that was overwhelmingly the telecommunications decision to make that move because it was so lucrative.. The general public was so against it that the switch over date got pushed back and back and back some more (the original date was sometime in 2005). But they finally got their way and basically said to people without digital tv's, "tough luck"!

So I have no doubts that if they really want to go in this direction, they will give us a few choices on WHICH download service we want to use, but that's as much choice in the matter as we will get. The players will all have the ability to hook-up to the internet and stream the movies all by themselves, people won't even have to own a computer.

There's just too much money to be saved by moving away from physical inventory not to do it really. I'm not saying I want it any more than you do. I'm just saying from a business standpoint its going to save studio's a TON of money. Not to mention the ability to control piracy, which is enemy #1 in their eye's.

Yeah, consumers dictate what succeeds, but only among the choices made available to us.

Whoa, off topic.

Your best bet would be to stick with bitstreaming the DD5.1 and DTS 5.1 soundtracks. If you go down to 2 channel then you are losing all the discrete surround effects. I can't tell a difference between HD audio and the DD and DTS lossy versions. The differences are pretty dang small. Remember also that BDs use the full bitrate available to DD and DTS while DVDs used more compression. So, your BDs, even in DD and DTS will still have higher quality than most DVD audio.

When you are removing the surround encoding by downrezzing to 2 channel, you are losing a lot more than a bit of dynamic range audible only to golden ears, you are losing 3 full channels of positioning information and that is most certainly noticeable even by untrained ears.

Errr... isn't it mandatory to steer a thread off topic on page #3???

I guess I'm new

Thanks a lot for the interesting and useful information.

About the DTS vs lossless, on the dvd Gladiator (not Blu Ray), the soundtrack is pretty amazing. Still can't believe the overall quality of this dvd for sound and picture. Upscaled, the picture "looks like" an high-def. You really need to stop the movie to see that it's not...