[harryposter]

Hi guys and sorry in advance for the long post:

I've just upgraded my PC sound system to a Logitech Z-5500 after my Creative one died, and connected my Sky HD Box directly to it through digital optical with a toslink cable.

The Logitech speaker system is also connected to my Creative Audigy 2 ZS Platinum card through 6 channels mini-jacks, with the TV connected to the front panel with standard stereo jacks.

I have been watching DD 5.1 movies from the Sky HD box through digital optical and while the surround sound is superb, when there are only dialogs the voice is coming from the center speaker only and sounds really poor. Nothing comes out of the other speakers.

However, when I switch to 6 channels direct through the PC, I have the sound of same movie processed in Dolby Prologic II to all speakers and dialogs/voice sound much richer and better, not only on center speaker but also on front left and right and much cleaner/clearer. The surround is quite good too but obviously not as good as DD 5.1 through digital optical cable.

So, to make the long story short:
- Through digital optical DD 5.1 direct from Sky HD box: music and surround sound effects are great, voice is crap and tiny on center speaker only.
- Through 6 channels direct from the PC's sound card with Dolby Prologic II Movie effect: overall sound is great especially voice, surround sound effects and music not as good as through digital optical though.

My main issue is sound quality of voice/dialogs: one speaker only (center) with DD 5.1 through optical (sounds like listening to a short-wave radio station), all front speakers with DPLII effect and sounds clear as on FM radio station.

My configuration, if this helps: Sky HD box connected direct to TV through HDMI for picture and connected direct to Logitech speakers' controller through digital optical for sound. TV connected to front panel of the Creative Audigy 2 ZS on my PC through standard stereo jacks (red and white). Audigy sound card connected to Logitech controller through 6 channel mini-jacks.

How come the sound from Sky HD Movies feels overall better through my PC with Dolby Prologic II than direct DD 5.1 through digital optical?
Is there anything wrong with the settings on the Sky HD box or the Logitech controller?

Have anyone experienced that or am I the only one to find that overall DD5.1 is not as good as Prologic, mainly because of the voice rendering problem?
Is DD 5.1 from Sky as good as it gets or is it supposed to be otherwise (ie the crappy voice sound problem)?

Any help would be much appreciated.

Thank you all.

[captainmccoy]

99% of the time dialogue is only supposed to come from the centre speaker.
If it is just coming from the centre speaker then that is correct - the fake surround effect you use might make voices louder but if they come from midair and no fixed position then you are listening in the wrong mode.
It sounds like your settings are wrong.

Go into TEST mode and adjust the volumes / distance settings for each of your speaker especially the centre so that the test signal is the same volume from all speakers while in your regular viewing position.

PL2 Movie is not usually accessible when a sountrack is in full 5.1 so it sounds like you are using the fake 6 channel stereo effect .

This is fine for cd's and gives what appears to be a much wider and more interesting soundfield , however for movies its not an accurate one.

If your setup has no test tone track down a dvd with the THX test setup .
The Star Wars dvd's have them but so do many others.

Although your DD light will light up to show that Sky is broadcasting a DD bitstream which it does 24 hours a day , full 5.1 sound movies should have the DD indication in the INFO banner.

Non 5.1 movies will be best heard in PL2 Movie setting and assuming you have an AUTO setting the full 5.1 soundtracks should switch in when available.

The 6 channel stereo sound is very nice but best used only for making stereo cd's more interesting.

Switching to PL2 will sound inferior initially but the sound engineer on the movie knows what he is doing so listen how he intended.

Main thing is checking the sound levels first

[john_locke]

seems obvious to me that the centre speaker is just not up to the job.

[paulr2006]

Quote:

Originally Posted by john_locke

seems obvious to me that the centre speaker is just not up to the job.

Agreed, PLII should sound much worse but as it's being spead out more between the rest of the speakers it is giving a better impression. If the centre speaker was up to the job then DD5.1 would sound far superior

[harryposter]

Quote:

Originally Posted by captainmccoy

99% of the time dialogue is only supposed to come from the centre speaker.
If it is just coming from the centre speaker then that is correct - the fake surround effect you use might make voices louder but if they come from midair and no fixed position then you are listening in the wrong mode.
It sounds like your settings are wrong.

Thanks for your comments guys.

Okay, so in DD 5.1 the norm is that most if not all of the dialogs/voice comes through the centre speaker, I guess I will just have to live with that and get used to it.

The thing is that when I use DPLII it comes mostly from the centre too, but I would say about 20% of dialogs also come through left and right front speakers which make it sound more natural to my taste as opposed to 100% coming from the centre (ie in real life, when someone facing you in a room speaks to you, some of his voice is reverberated by the walls and you can hear some of it coming from the sides/back, not only from the centre as in DD 5.1).

The other annoying thing is that the sound from my Sky HD box in DD 5.1 seems to have its frequency range truncated as if it was in night mode or something (that's what I meant with the AM/FM radio comparison in my first post), so in DD 5.1 dialogs/voice come from the centre but also sounds like AM or hearing the voice from a telephone, with low and high frequencies just not there, as opposed to being full range and much more clear/natural when listening with Dolby Prologic II.

I've checked the levels of all my speakers and they are all fine, are there any sound settings I can tweak on the Sky HD box or would using coax digital instead of optical be better (I have the Pace one, with both coax and optical digital out)? I have read something in other threads and forums about enabling optical digital and/or disabling Dynamic Range Compression on Sky HD box to get the most of DD 5.1 but cannot find any of these in the sound settings (I've got only three controls: Audio Output - set to stereo, Digital Audio Output - set to Dolby D and Digital Audio Output Delay - set to 0ms). And my Logitech control centre correctly shows the signal as being Optical/Dolby Digital.

Are there any hidden sound settings on the Sky box that would sort this out?
Or is it just the way Sky encode their DD movies? (I haven't tried with a DVD yet to tell if there is any difference).

Any idea? Sorry to be a pain and thank you for your help.

[harryposter]

Tried the coax... I can't believe it, much better DD sound than optical now!
I thought optical was better. Well, I've got an extra cable now and will use it for the PS3
Voices still in the centre but it varies with movies and it's supposed to be like that anyway, I'll just switch to DPLII when I don't like it.

Thank you all for your help!

[john_locke]

well you really should try with a DVD, obviously.

With movies & 5.1 tv shows, the centre is where the dialogue is locked but reverberation from the dialogue and other center-locked events does go to the other 4 speakers as well (depending how the mix is done, but this is broadly true). It sounds to me almost like your subwoofer isn't doing the bass management job that it's supposed to - with a centre speaker as small as yours, there should be quite a lot of low end stuff from the centre also coming from the sub, which should be making up for the smallness of the centre. In DPL, your system is apparently doing some divergence, which is sending some centre to the L&R and perhaps it's also using the subwoofer properly?

Very much doubt coax digital will make any difference, but worth a try, why not?

Dynamic range compression from the multichannel digital outputs is only enabled in the amplifier that receives the signal - so your logitech system, if it has such options. It doesn't really make such a radical difference as you describe though. There's not much else to do with the options in the box. Thing is, there's so many people using these DD streams to good effect that the answer really must lie somewhere in the Logitech. Maybe if you used a particular Anytime film that we could also listen to, we could compare apples with apples?

[captainmccoy]

Quote:

Originally Posted by harryposter

Tried the coax... I can't believe it, much better DD sound than optical now!
I thought optical was better. Well, I've got an extra cable now and will use it for the PS3
Voices still in the centre but it varies with movies and it's supposed to be like that anyway, I'll just switch to DPLII when I don't like it.

Thank you all for your help!

Dialogue will only come from elsewhere if its supposed to.
For example - if someone is off screen to the left then their voice will come from that side .
The only reason dialogue normally comes only from the centre is because whoever is speaking is usually onscreen at the time .

Either your cable or your amp must be faulty as you should notice no difference between optical and coaxial

[john_locke]

there must be an issue in the logitech's input section. As you rightly say, the stream is the stream, on optical or coaxial.

[harryposter]

Quote:

Originally Posted by john_locke

there must be an issue in the logitech's input section. As you rightly say, the stream is the stream, on optical or coaxial.

It's definitely not my setup nor the Logitech Z-5500 that are in fault:
I just tried Wall.E that I recorded a couple of weeks ago from Disney Cinemagic HD and the DD5.1 sound is as it should be: perfect! Magnificient, rich, clear, full range and so on.

My sound problems only occur with Sky HD movie channels, which I think use a different Dolby encoding for some reason as I have read on other posts/forums saying that they are in breach with Dolby's specs in some way.

I tend to believe this as the frequency range is clearly not as wide from Sky channels compared to others in DD.

Also checked with a DVD through optical from the PS3 and here again the sound is perfect.

It's only with Sky HD channels (I mean the ones from BskyB) that I have to switch to DPLII to get a decent sound.

Why would they do that when the sound is perfect on non-Sky channels like Disney, BBC HD, Discovery et al?

[bobcar]

Quote:

Originally Posted by harryposter

Tried the coax... I can't believe it, much better DD sound than optical now!
I thought optical was better. Well, I've got an extra cable now and will use it for the PS3
Voices still in the centre but it varies with movies and it's supposed to be like that anyway, I'll just switch to DPLII when I don't like it.

Thank you all for your help!

There may be a fault somewhere in the system as optical and coaxial should be identical, if you eliminate the amp and cable by using something else as an input then that would just leave the Sky+HD faulty though it doesn't matter if the coaxial is okay. (Very strange fault though to be able to get sound through the optical at a lower quality than the coaxial - it's most likely either finger trouble or your imagination).

[Pugwash69]

Quote:

Originally Posted by john_locke

seems obvious to me that the centre speaker is just not up to the job.

I'd agree to this too. The centre speaker is very important. I have a nice Eltax of some flavour that cost as much as the front L&R pair.

Is the coax mix being processed in some way that mixes it into the L&R?

[harryposter]

Quote:

Originally Posted by bobcar

There may be a fault somewhere in the system as optical and coaxial should be identical, if you eliminate the amp and cable by using something else as an input then that would just leave the Sky+HD faulty though it doesn't matter if the coaxial is okay. (Very strange fault though to be able to get sound through the optical at a lower quality than the coaxial - it's most likely either finger trouble or your imagination).

Sure it sounds better by switching from optical to coax for some reason even on the Sky Movie channels (maybe it's just the optical output on the sky box that is faulty as it workx perfectly on the PS3?), but what I am saying is that sound quality is still poor on these compared to Disney, Discovery etc.
Basically it's like hearing 100Hz-10kHz on Sky Movie as opposed to proper 20Hz-20kHz on the others.

Or is it just down to whatever efforts film producers are bothered to put in the sound and it varies from one to another?

To be able to compare I would have to see (hear) Wall.E on a Sky Movie channel as the one I tested was on Disney.

I mean, I am watching Quantum of Solace right now on Sky Screen 1 HD and the DD sound is just okay, nothing gobblesmacking.
I don't have the DVD but I suspect it would sound better from it.
So why would it sound better from a BD/DVD or from a non-Sky HD channel than from Sky Movie when the dolby encoding is supposed to be exactly the same at the source?

Again, this is just an assumption as I don't have the DVD to compare, has anyone done it with this one or another film?

[harryposter]

Quote:

Originally Posted by Pugwash69

I'd agree to this too. The centre speaker is very important. I have a nice Eltax of some flavour that cost as much as the front L&R pair.

Is the coax mix being processed in some way that mixes it into the L&R?

The coax is not processed whatsoever, it goes straight from the Sky HD box to the Logitech Z-5500 control center and I have no control on L&R when the source is DD5.1

[bobcar]

Quote:

Originally Posted by harryposter

Sure it sounds better by switching from optical to coax for some reason even on the Sky Movie channels (maybe it's just the optical output on the sky box that is faulty as it workx perfectly on the PS3?), but what I am saying is that sound quality is still poor on these compared to Disney, Discovery etc.
Basically it's like hearing 100Hz-10kHz on Sky Movie as opposed to proper 20Hz-20kHz on the others.

There are two very different issues here.

One is the sound being worse on some channels than others. This is perfectly understandable and I'm sure you're right, just as with picture quality the level of compression will vary from channel to channel.

The other is the difference between optical and coaxial. It's very hard to see any fault that could account for a difference as it's the same signal and a fault should result in the loss of audio or very bad break up. That is why I would come to the conclusion that you are imagining it (I'm not getting at you, I'm just as capable of imagining a difference that isn't there) or that there is some finger trouble and that when you think you are using optical you are somehow feeding back from the TV or similar.

[john_locke]

I too think something else is at work here. Sky HD's movies are mostly transmitted from Dolby E encodings done by the studios. There isn't a variable compression system in that same way as there is for the picture, it's 448kb/s but can be forced a bit lower if you really try (no-one does). There is metadata to be considered but it cannot change the EQ of soundtracks, just compression.

You say the result was changed massively by switching to coaxial...but, then you say it is still bad. So...what's cinemagic HD like on optical compared to coaxial?

there have been some historical drop-out issues with the DD stream that affected drop-out on certain amplifiers, but nothing that affected fundamental sound eq.

[frasera]

Quote:

Originally Posted by john_locke

seems obvious to me that the centre speaker is just not up to the job.

yup in 5.1 the center speaker is the MOST important, you don't skimp out on it. to fill a room with clear sound you really need a pretty substantial speaker. the issue is this is a computer speaker, near field use is what its for, it needs to be right in front of you on a desk. its not made for home theater.

false surround ddII basically spread the load around making it appear to sound better, but its mostly masking the inadequacy of the speakers.

[Chris Frost]

Quote:

Originally Posted by frasera

yup in 5.1 the center speaker is the MOST important, you don't skimp out on it. to fill a room with clear sound you really need a pretty substantial speaker. the issue is this is a computer speaker, near field use is what its for, it needs to be right in front of you on a desk. its not made for home theater.

false surround ddII basically spread the load around making it appear to sound better, but its mostly masking the inadequacy of the speakers.

Good post

[grahamlthompson]

If you tune to the BBC HD preview loop about 10:30 every day there is a HD test card broadcast. This also has a full 5.1 sound test. The output tone should sound the same from each of the 5 speakers at your normal viewing position.

It's a good idea to record this and use it to set up the system levels.

[GetFrodo]

It's been ages since I've had sky so can't remember the exact menu options, but are you really sure that you have set up sky to output proper surround sound on the optical output?

Something like this: http://www.avforums.com/forums/sky-s...-plus-box.html