Q. about cable TV and Dolby surround

[jdmack]

This question is most likely for the U.S. readers, but I may be wrong.

Can anyone give me a list of network broadcasts that are encoded for some sort of Dolby surround? I want to test my system. The network homepages don't seem to have any information of this sort.

I have the most basic of basic cable - just the main broadcast networks and a few public access channels. I have the coaxial cable going into my hi-fi VCR, and then I have the stereo line outputs going to my RCA STAV-3970 receiver. If I use the VCR to tune the channel that I want to watch, I get stereo audio with no problem. But if I engage the Dolby Pro Logic switch, suddenly just about everything comes out of the center speaker. I tried this tonight with an NFL football game, and while I could hear some ambient crowd noise coming out of the front and rear speakers, I had to put my ear right next to the speakers to hear it. Meanwhile, most of the main audio is coming from my center speaker.

I have no problem playing DVDs through this receiver and hearing surround sound.

What should I do differently?

J. D.

 

[spenceo]

I've always found that you are at the mercy of you local cable company and more often at the mercy of you local broadcaster. Most of the Cable channels (ie. History, Discovery, TBS) have good matrix systems. The local broadcasters (ie. you local ABC, FOX, CBS) depend on there hardware and /or their personnel to set it up correctly. For example on my local cable I get NBC out of Cleveland, OH, Columbus, OH and Wheeling , WV. The Cleveland NBC OK, The Columbus NBC better and the Wheeling mono only. I also found that the signal through my Dish Network sat system to be the best.

Spence

 

[Guy Robinson]

I also found that the signal through my Dish Network sat system to be the best.
Spence

In Canada we have a Bell satellite system which is marketed as ExpressVu. I have the box connected directly to my receiver via Toslink. The sound quality is pretty good generally and Dolby is sporadic. The best part is of course the time shifting where you get all the major networks from Eastern to Western Canada as well as the U.S. channels which means all of the primetime shows on major networks can be watched anytime during the evening by choosing the right time-zone. Anyway, I'm sure I'm telling no one here anything new so I will be quiet now......

 

[Desmo888]

The Super Bowl will be broadcast in Dolby.

 

[sspsandy]

I've run cable and now Dish network satellite TV through my Tate quad decoder. The majority of tv shows, commercials, and movies decode beautifully giving a nice surround sound. The exceptions are movies that are mono and certain news programs. In those cases I can switch to the mono mode on the Tate to get a nice ambient surround.

My experience with Pro Logic II is that if you have a mono source you get no surround info. As to it going only to the center channel, that may have to do either with how you have your settings on the receiver, or with the scheme the processor in the unit uses. I would suggest getting a good stereo VHS music tape and see how it decodes. An example is The Dance by Fleetwood Mac, which is Dolby Surround encoded. It really comes alive.

I use a switch to send my tv box to the VCR. I recommend sending the left and right RCA outputs from your cable box directly to the receiver L&R inputs. If I want to watch a VCR, I use the switches to send the info directly to the receiver. I don't like passing the signal through the VCR. In order to be able to record tapes you actually need two switches. One acts as a loop that sends the outs from the box through the VCR to the receiver. The other switches the outs from the VCR and the TV box to the receiver. In order to record a tape you set both switches (one is marked Play/Record the other TV/VCR). Hope this helps.

 

[jdmack]

I recommend sending the left and right RCA outputs from your cable box directly to the receiver L&R inputs.

In my case, I do not have a cable box. I run the cable that comes into my house straight into my cable-ready VCR and TV (using a splitter).

J. D.

 

[sspsandy]

I have always found that you get a mono signal out of a stereo VCR when you run the coax cable into the input. What I recommend is going to Radio Shack and picking up an RF modulator. This is a box designed to put a coax cable into the input side, and converts it to a left, right, and video RCA connection. They run about $20.00. They are used for connecting a DVD player to a TV with only a coax connection, but they work the other way as well. Every stereo VCR I've ever owned needed to use the RCA inputs to get stereo from the RCA outputs.

 

[leevitalone1]

This question is most likely for the U.S. readers, but I may be wrong.

Can anyone give me a list of network broadcasts that are encoded for some sort of Dolby surround? I want to test my system. The network homepages don't seem to have any information of this sort.

I have the most basic of basic cable - just the main broadcast networks and a few public access channels. I have the coaxial cable going into my hi-fi VCR, and then I have the stereo line outputs going to my RCA STAV-3970 receiver. If I use the VCR to tune the channel that I want to watch, I get stereo audio with no problem. But if I engage the Dolby Pro Logic switch, suddenly just about everything comes out of the center speaker. I tried this tonight with an NFL football game, and while I could hear some ambient crowd noise coming out of the front and rear speakers, I had to put my ear right next to the speakers to hear it. Meanwhile, most of the main audio is coming from my center speaker.

I have no problem playing DVDs through this receiver and hearing surround sound.

What should I do differently?

J. D.

Here is what I see, you are tyring to get a signal I don't think you can. 1st you will need a scource for dolby digital. Pro-logic can be gotten from any stereo scource. Trouble is you see it encoded on vcr tapes. all major nets broadcast DD. And cannot be had from a stereo scource as you describe, from your vcr. Sat providers offer receivers that will out put a digital audio signal. Reemember not all DD is surround. some is 2.0. How can you tell? Ussually it will appear on a channel banner. or your receiver will pick up a signal.

 

[sspsandy]

My experience is that much of what is broadcast will decode into surround quite nicely either through a decent quad decoder, or through a Dolby Prologic II or equivalent matrix processor. As long as you can get a true stereo feed from the VCR, it will work. I have experience with Pro-Logic II processors and they will convert a stereo signal into reasonable surround. Also, since the majority of DVDs have surround encoding included on the stereo tracks, it appears that many of the broadcast movies contain it as well.

 

[DaneelOlivaw]

I have our coax cable from the wall going into my Panasonic Hi-Fi stereo VCR then its stereo outputs hooked into my receiver.If the show has a *true* surround track AND the channel is broadcast in stereo, the Dolby Pro-Logic setting works nicely. The Simpsons usually has a good surround mix believe it or not. I dont use a center chanenl so am not sure what it sounds like with one installed.

Ball games are really hit or miss some have full audience and ambient noise from the rears, some just a whisper.

 

[jdmack]

Here is what I experienced during the Super Bowl last night.

My amplifier allows me to turn the individual 5.1 channels up and down on a scale of -10 to +10. if I turned the center channel down to -3, and turned the rear speakers up to +10 each, then it sounded *OK*. The thing that bothered me the most is someone seemed to be riding the gain on the audience sound in the rears. It would fluctuate from barely audible to overpowering - and not just when the crowd was reacting to something exciting.

J. D.

 

[neil wilkes]

I have our coax cable from the wall going into my Panasonic Hi-Fi stereo VCR then its stereo outputs hooked into my receiver.If the show has a *true* surround track AND the channel is broadcast in stereo, the Dolby Pro-Logic setting works nicely. The Simpsons usually has a good surround mix believe it or not. I dont use a center chanenl so am not sure what it sounds like with one installed.

"The Simpsons" is Dolby Surround encoded - it says so in the credits.
You will find a lot of drama is also Lt/Rt encoded.
If the output from the cable/satellite is a digital one, you will still get the Surround encoding - but unless it is specifically discrete, the odds are overwhelming that it will be standard LCRS type encoding, so set the Dolby Pro Logic decoders to Matrix as this is the DPL II emulation of the original Dolby Surround. The Movie setting can work well also - it depends on the source.
Trouble with the dreaded Dobly is that most of the cable/satellite stations are - when doing events like Superbowl, or the World Cup, are actually mixing to 5.1 discrete in the OB trucks, yet then running the discrete mix through LCRS encoders followed by Dolby SR for "noise reduction" to eliminate the noise that has invariably been introduced BY the LCRS encoder!

Backwards compatibility - gotta love the mess it makes.

 

[KMO]

I use PLII Movie almost exclusively for 2-channel TV content; plenty of stuff is Dolby Surround encoded, and that which isn't usually doesn't cause any problems.

And I've got no problems at all with mono stuff only coming out of the centre speaker; it's the way it should be, as far as I'm concerned.

But one oddity I've noticed increasingly frequently is broadcasts that seem to cause the sound to come out of all 5 speakers; presumably there's a minor phase shift between the two channels causing the decoder to scatter the sound everywhere.

But a cynical little part of me can't help but think it might be a deliberate effect applied to appease those who either don't like everything being in their centre speaker, or those who have it badly calibrated and then phone in to complain they can't hear the dialogue... Best to have everything come out of all 5 speakers to be on the safe side, eh?

 

[DaneelOlivaw]

^ I have also watched shows where each speaker had pretty much the same signal which I don't like. I felt like i was in a cave!

Also, I have heard broadcasts where all the dialog & everything else came out of the REAR channels, just last week actually. Commericals sometimes do this also. Very weird. And on my "Sealab 2021" Season 3 dvds with Dolby Digital, which on my receiver lights up the "S" channel indicator plus the L & R indicators, on some of the episodes much of the main dialog is emitted from the rear channels too so I just choose the receiver's stereo mode instead.

I do not think there are standards for movies and TV audio, are there?

 

[KMO]

If everything is coming out of the rears, then the left & right channels being broadcast are 180 degrees out of phase. I've never seen that happen myself, but it's certainly an easy mistake to make; but equally easy to spot though.

As for your DVD player and SeaLab, that's very odd - the audio is 2.0 channel, with the flag indicating that it's Dolby Surround encoded. In which case, I wouldn't expect anything odd to happen.

If a stereo film or TV isn't specifically Dolby encoded, then the results of applying Dolby Pro Logic decode to it would be variable. But a large amount of material out there is specifically Dolby Surround encoded - either mixed 4-channel LCRS, or in full 5.1 and folded down.

There certainly are a number of standards with regard to broadcast audio, but whether they're Dolby Surround encoded is up to the programme makers. However, the standards I've seen such as BBC ones highlight the fact that left/right phase errors must be prevented to avoid problems with Dolby decoders and mono fold-down. I imagine Texas TV is slightly less rigorous than the BBC though...

 

[DaneelOlivaw]

I imagine Texas TV is slightly less rigorous than the BBC though...

I wouldn't be surprised. And this is not the same issue but quite a few times the past year on the History Channel, my favorite cable station, the picture/sound has 100% blanked out, sometimes for almost a full minute, with only a black screen along with the words "poor signal" displayed (we have regular analog cable & dont use any set top boxes). Other channels sometimes have random pixelation, so bad peopels faces are unrecognizable. Severe weather somewhere I guess?

 

[neil wilkes]

I imagine Texas TV is slightly less rigorous than the BBC though...

These days, I would not be so sure about that.
The quality of the BBC is not what it was......

 

[KMO]

The thought did cross my mind while writing that, but then I suspect Texas TV isn't what it was either