Audio sync question

Archived from groups: alt.tv.tech.hdtv (More info?)

Thank you for your post. I've been considering the purchase of a HDTV and
had considered the Samsung, but was concerned due to the audio sync issues.
I've been researching the issue and the problem is chronic with the Samsung
DLP's. Some had said the issue was fixed with the later units, but
apparently that is not the case. What is happening is that the Samsung is
taking longer to convert the video from your DVD player to 720p (the format
used by the Samsung's display) than it takes your receiver to process the
audio. If you use the Samsung's built in speakers, it automatically adds a
delay to the audio to keep things in sync. If you use an external receiver,
than there is no delay. Samsungs solution to the problem is to either use
the built in audio out jacks and mute the TV (which will then include the
delay, but will NOT offer Dolby surround as the TV's audio out jacks are
analog only) or to buy a new home theater receiver that includes the ability
to add a delay to the audio. Neither solution is acceptable to me. Samsung
should have included digital input and output jacks for sound (as Hitachi
and other vendors have done.) Do a google search on "Samsung audio sync
DLP" and you will find many, many long discussions on this topic. Good
luck.
Craig

"Guy" <newsgroupposter@hotmail.com> wrote in message
news:1103475183.602331.320200@f14g2000cwb.googlegroups.com...
> Just got a Samsung DLP HL-P5063W. Slowly integrating it with my modest
> sound system--a mid-level two-to-three-year-old Sony STR-DE875 receiver
> and a low-end-but-Progressive-Scan Toshiba SD-3960 DVD player. The DVD
> player's video is connected to the TV via Monster component cable; the
> audio is connected to the receiver using standard analog cables. The
> DVD player also has digital coax out, but I haven't picked up a digital
> coax cable yet.
>
> While watching a movie last night, I noticed that the audio was
> constantly out of sync with the video. Usually only a fraction of a
> second, but frequently more so. The difference grew and shrunk
> throughout the whole movie. Other family members noticed the delay,
> too, so it must have been pretty bad. ;^)
>
> I'm wondering what this is attributable to:
> - Using analog cables (to be fixed)
> - Limitations of the Sony receiver (could be fixed with a new receiver)
> - Sending the video and audio to different devices (not easy to fix
> without getting a receiver that has adequate video support)
> - Something else?
>
> Thanks for your thoughts on this!
>

Archived from groups: alt.tv.tech.hdtv (More info?)

Guy wrote:
> Thank you for responding. The problem you describe would result in the
> video being *behind* the audio; the problem I am seeing, however, is
> that the video is *ahead* of the audio.

Craig's explanation is at best considerably oversimplified. There are
some audio sync issues in last year's model Samsung DLPs, but it's been
corrected in the newer sets. In your situation, the problem may be in
the DVD player, or it may be a combination of factors.

I recommend that you try using a digital link from your DVD player to
your receiver. You might as well try the cheapest solution first.

Each of the units in your system (TV, DVD, receiver, cable box, etc) is
capable of delaying its part of the signal somewhat. It can be tricky
to get good synchronization between the audio and the video. Do some
experimenting and you'll figure out where the problem lies. You might
want to try a different DVD player just to see if the problem is
entirely there.

Archived from groups: alt.tv.tech.hdtv (More info?)

FWIW, I have an HNL57W and have never ever noticed an audio sync problem except
on broadcast TV, and even then it depends on the station. With some there's a
very noticeable delay and others, there's not. UHF seems fine, VHF is another
matter. The TV is connected to Sony receiver (can't recall the model number)
via an optical connector. No sync problem either with either the speakers in
the TV or the sound system.

"Guy" <newsgroupposter@hotmail.com> wrote in message
news:1103475183.602331.320200@f14g2000cwb.googlegroups.com...
> Just got a Samsung DLP HL-P5063W. Slowly integrating it with my modest
> sound system--a mid-level two-to-three-year-old Sony STR-DE875 receiver
> and a low-end-but-Progressive-Scan Toshiba SD-3960 DVD player. The DVD
> player's video is connected to the TV via Monster component cable; the
> audio is connected to the receiver using standard analog cables. The
> DVD player also has digital coax out, but I haven't picked up a digital
> coax cable yet.
>
> While watching a movie last night, I noticed that the audio was
> constantly out of sync with the video. Usually only a fraction of a
> second, but frequently more so. The difference grew and shrunk
> throughout the whole movie. Other family members noticed the delay,
> too, so it must have been pretty bad. ;^)
>
> I'm wondering what this is attributable to:
> - Using analog cables (to be fixed)
> - Limitations of the Sony receiver (could be fixed with a new receiver)
> - Sending the video and audio to different devices (not easy to fix
> without getting a receiver that has adequate video support)
> - Something else?
>
> Thanks for your thoughts on this!
>

Archived from groups: alt.tv.tech.hdtv (More info?)

Somewhere around 19 Dec 2004 08:53:03 -0800, while reading alt.tv.tech.hdtv,
I think I thought I saw this post from "Guy" <newsgroupposter@hotmail.com>:

>Just got a Samsung DLP HL-P5063W. Slowly integrating it with my modest
>sound system--a mid-level two-to-three-year-old Sony STR-DE875 receiver
>and a low-end-but-Progressive-Scan Toshiba SD-3960 DVD player. The DVD
>player's video is connected to the TV via Monster component cable; the
>audio is connected to the receiver using standard analog cables. The
>DVD player also has digital coax out, but I haven't picked up a digital
>coax cable yet.
>
>While watching a movie last night, I noticed that the audio was
>constantly out of sync with the video. Usually only a fraction of a
>second, but frequently more so. The difference grew and shrunk
>throughout the whole movie. Other family members noticed the delay,
>too, so it must have been pretty bad. ;^)
>
>I'm wondering what this is attributable to:
>- Using analog cables (to be fixed)
>- Limitations of the Sony receiver (could be fixed with a new receiver)
>- Sending the video and audio to different devices (not easy to fix
>without getting a receiver that has adequate video support)
>- Something else?
>
>Thanks for your thoughts on this!

Do you mute the audio on the TV? It makes a huge difference between
actually muting the audio, and simply turning down the volume.

--
Marty - mjf at leftcoast-usa.com
"Those are my principles, and if you don't like them...
well, I have others." - Groucho Marx

Archived from groups: alt.tv.tech.hdtv (More info?)

At this point, the only audio connection is between the DVD player and
the receiver, via standard analog RCA cables.

Archived from groups: alt.tv.tech.hdtv (More info?)

Somewhere around 22 Dec 2004 13:24:35 -0800, while reading alt.tv.tech.hdtv,
I think I thought I saw this post from "Guy" <newsgroupposter@hotmail.com>:

>At this point, the only audio connection is between the DVD player and
>the receiver, via standard analog RCA cables.

So, did you turn on the audio mute for the TV? If so, did that make a
difference?

--
Marty - mjf at leftcoast-usa.com
"Those are my principles, and if you don't like them...
well, I have others." - Groucho Marx

Archived from groups: alt.tv.tech.hdtv (More info?)

Is the audio late or early?
By the way, a coax cable doesn't care if it's a digital or analog signal
going through it. You can use any old RCA cable for the short distance
between a DVD coaxial digital out and a receiver's coaxial digital in. Save
money, don't buy expensive cables, they are not worth it, there is no
difference that human eyes and ears can detect.

"Guy" <newsgroupposter@hotmail.com> wrote in message
news:1103831567.700808.263040@f14g2000cwb.googlegroups.com...
> No, I can't say that I have muted the TV. I will try it. But since
> there is no audio going to the TV, why would that make a difference?
>

Archived from groups: alt.tv.tech.hdtv (More info?)

Jim Gilliland wrote:
>
> But there is a big and very real difference between
> typical analog coax and digital coax.

There can be.

> Digital coax, carrying S/PDIF,
> Dolby Digital, or DTS signals, needs to be a proper 75 ohm cable.

They should be.

> While
> you may succeed in getting a digital signal to pass through a
> non-standard cable, you are very likely to get errors that may cause
> dropouts and other audible problems.

Not unless the length of the cable approaches 1/4 of the wavelength of
the signal.

> And since 75 ohm cable can be
> purchased at very reasonable prices, it really doesn't make sense to try
> to force digital data through a cable that isn't designed for it.

True enough, but at the distances that most HT cables have to cover,
shielding is far more important than the characteristic impedance.

> Fortunately, 75 ohm digital audio cable is exactly the same as video
> cable. So any cable that is properly designed to carry composite video
> will also work correctly to carry digital audio.

Agreed.

> But a typical cheap
> plain audio cable with RCA connectors on each end will NOT be a good
> choice for digital audio.

Try it. If there are bit errors, the resulting noise will not be subtle.
High order bits are a likely to be in error a low order bits. The effect
will be even more exaggerated on Dolby Digital and DTS signals. In
general, a well shielded audio cable will carry component video and
digital audio with artifacts well under measurable with anything less
than a spectrum analizer.

Matthew

--
Thermodynamics and/or Golf for dummies: There is a game
You can't win
You can't break even
You can't get out of the game

Archived from groups: alt.tv.tech.hdtv (More info?)

"Jim Gilliland" <usemylastname@cheerful.com> wrote in message
news:QeudnaL7gd6NK1PcRVn-qA@adelphia.com...
> Matthew L. Martin wrote:
>
>>> But a typical cheap plain audio cable with RCA connectors on each end
>>> will NOT be a good choice for digital audio.
>>
>> Try it. If there are bit errors, the resulting noise will not be subtle.
>> High order bits are a likely to be in error a low order bits. The effect
>> will be even more exaggerated on Dolby Digital and DTS signals. In
>> general, a well shielded audio cable will carry component video and
>> digital audio with artifacts well under measurable with anything less
>> than a spectrum analizer.
>
> I have tried it in a pinch, and yes, you can get away with it in some
> cases. I suspect that dropouts are more likely to result than digital
> distortion, as the receiving component will have trouble extracting the
> clock consistently. But over short distances it isn't likely to be a
> problem. And providing further support for your side of the argument,
> many "better" audio cables _are_ made from 75 ohm cable these days.
>
> But considering the potential for trouble and the low cost of real 75 ohm
> cables, I don't think it makes sense to recommend this approach to others
> here. In any event, I don't think you and I are in much disagreement.

I'm with you, it's not a big deal to get the right cable. On the other hand,
there is nothing wrong with trying a cable that's just lying around unused
anyway. If it works and there no drop-outs, use it. There are no
improvements to be had at this point, other than psychological ones. Too
many sales persons tried to make people believe that there is such a thing
as a "digital" or "digital ready" cable (same with "digital ready"
loudspeakers). I think it's partially because of ignorance and partially
because of greed. I have looked at cables in one of the big electronics
stores before, and they are good cables. Since I am in the A/V industry, I
know how much these cables cost. Here's a high figure for a 5' component
video cable:
Canare V3-CFB @ $1.50/ft - $7.50
6 x RCA connector @ $2 ea. - $12.00
That's $19.50 for a 5' component cable. This kind of cable beats anything
ever sold at the big stores as far as quality is concerned. A 5' component
cable cost $50 at Best Buy. That's more than a 100% mark-up. Cost for their
5' cable is probably a lot less than my estimate, maybe as low as $10. I
have had a sales person admit to me one time that customers are drawn to the
store by the $50 DVD player. The store doesn't make much money on the DVD
player, but sells the cable and service contract for it, and that's where
the profit is.
I think it's a shame. On the other hand, since I don't buy these expensive
cables, I enyoy that the big electronics stores can afford, because of the
cheap cables sold for a lot of money, to sell electronics cheap.

Archived from groups: alt.tv.tech.hdtv (More info?)

Somewhere around Mon, 27 Dec 2004 14:22:05 GMT, while reading
alt.tv.tech.hdtv, I think I thought I saw this post from "Hasenpfeffer"
<hasenpfeffer@triad.rr.com>:

>
>"Jim Gilliland" <usemylastname@cheerful.com> wrote in message
>news:QeudnaL7gd6NK1PcRVn-qA@adelphia.com...
>> Matthew L. Martin wrote:
>>
>>>> But a typical cheap plain audio cable with RCA connectors on each end
>>>> will NOT be a good choice for digital audio.
>>>
.. . .
>I'm with you, it's not a big deal to get the right cable. On the other hand,
>there is nothing wrong with trying a cable that's just lying around unused
>anyway. If it works and there no drop-outs, use it. There are no
>improvements to be had at this point, other than psychological ones. Too
>many sales persons tried to make people believe that there is such a thing
>as a "digital" or "digital ready" cable (same with "digital ready"
>loudspeakers). I think it's partially because of ignorance and partially
>because of greed. I have looked at cables in one of the big electronics
>stores before, and they are good cables. Since I am in the A/V industry, I
>know how much these cables cost. Here's a high figure for a 5' component
>video cable:
>Canare V3-CFB @ $1.50/ft - $7.50
>6 x RCA connector @ $2 ea. - $12.00
>That's $19.50 for a 5' component cable. This kind of cable beats anything
>ever sold at the big stores as far as quality is concerned. A 5' component
>cable cost $50 at Best Buy. That's more than a 100% mark-up. Cost for their
>5' cable is probably a lot less than my estimate, maybe as low as $10. I
>have had a sales person admit to me one time that customers are drawn to the
>store by the $50 DVD player. The store doesn't make much money on the DVD
>player, but sells the cable and service contract for it, and that's where
>the profit is.
>I think it's a shame. On the other hand, since I don't buy these expensive
>cables, I enyoy that the big electronics stores can afford, because of the
>cheap cables sold for a lot of money, to sell electronics cheap.
>
I agree that many cables are rediculously overpriced. I believe in getting
good quality cables, and heavy-duty speaker cables, etc, but there's a big
differrence in price between the designer cables and the simply good ones
that I don't think is justified, especially after I had a monster audio
cable come apart on me, even though I was careful (the inside housing ripped
right out and stayed in the jack).

I wondered about the coax digital - I tried a standard audio cable for my
DVD output, and it didn't work at all. I'll try a video cable, and if it
doesn't work, I'll recheck the setup. I bought an optical cable already,
and it does work, so I wasn't tempted to buy a digital cable. In fact, it's
hard to figure out what to buy anyway, as it seems like every kind of cable
these days is called digital - s-video, composite video, audio, etc. What a
crime.

--
Marty - mjf at leftcoast-usa.com
"Those are my principles, and if you don't like them...
well, I have others." - Groucho Marx

Archived from groups: alt.tv.tech.hdtv (More info?)

Thanks for that. Yeah, I figured it was the Mute button on the remote.

I have my HTS configured so that we can watch TV with or without
turning on the receiver. How easy is it to change the Internal Mute
setting?