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The HDMI Cable Discussion - Page 15

post #211 of 338

Why are HDMI cables shielded at all, let alone the longer ones? 

 
I answered that in detail many pages back, don't you remember?
 
 

Edited by ac500 - 2/28/12 at 9:32am
post #212 of 338

 

Okay, so just to refresh my memory here further.

 

Shielding is done to make sure that no interference occurs. Otherwise, you all sorts of crap on your screen (which we discussed already).

 

And of course, it could result with some signal that isn't too strong, or cluttered somehow.. or no signal at all.

 

 

However, what happens in regards to the argument of 'there's either a signal, which produces the highest quality possible, or there isn't one' ?

post #213 of 338
Quote:
Originally Posted by Shotor102 View Post

 

Okay, so just to refresh my memory here further.

 

Shielding is done to make sure that no interference occurs. Otherwise, you all sorts of crap on your screen (which we discussed already).

 

And of course, it could result with some signal that isn't too strong, or cluttered somehow.. or no signal at all.

 

 

However, what happens in regards to the argument of 'there's either a signal, which produces the highest quality possible, or there isn't one' ?



There is a certain margin of error that can be accepted.  If you look at the signal at the end with an oscilloscope, you will see that it is not a perfect square wave.  In order for the receiver at the end to tell whether the bit is a 1 or a 0, the signal needs to be close enough to an actual square - otherwise, the "box" you can put between the different bits on the visual graph will be closed off, and the receiver won't be able to read it.

 

I'm not sure if I've done a very good job at explaining or not...but there are a few better explanations online somewhere if you care to look.

post #214 of 338

But HDMI uses error correction, not error retrieval? So the image displayed, even if for just a picosecond, is not exactly the one sent. Don't throw me into the fire pit just yet, I'm not saying this is in any way noticeable, I'm just asking.

post #215 of 338

I think ac500 covered that in post 12.

post #216 of 338
Quote:
Originally Posted by Shotor102 View Post

 

Okay, so just to refresh my memory here further.

 

Shielding is done to make sure that no interference occurs. Otherwise, you all sorts of crap on your screen (which we discussed already).

 

And of course, it could result with some signal that isn't too strong, or cluttered somehow.. or no signal at all.

 

 

However, what happens in regards to the argument of 'there's either a signal, which produces the highest quality possible, or there isn't one' ?


I don't think anyone is arguing that there is an absolutely perfect signal for every single to spec cable. Errors still happen but at a very small level that wouldn't, or at least shouldn't, be noticeable once it makes it to the screen.

 

The signal/no signal thing is also accounting for the TV to properly detect errors and decide when the cable has connectivity issues. If the image is being displayed, then the signal should be a proper signal. If it's not being displayed, a problem with the signal has been detected. Now, this doesn't necessarily mean that absolutely no signal is making it through, but there has been enough of a problem to consider it not a proper connection.

 

I don't believe anyone specifically addressed my understanding of the cable design earlier, so I'm going to assume that I have a proper understanding. The HDMI cable is designed to send the signal twice at the same time. One is the "original" signal and the other is the same signal but inverted. These signals are sent through different channels. The receiving device receives both of these signals and compares them in order to detect and correct for errors. If my understanding is correct, then I believe you would need the channels for both the original and inverted signal to be affected in exactly the same way at the exact same time. Otherwise, the interference would cause errors that would be detected and with enough errors the TV should indicate that there is a connectivity issue. The idea is that the TV should identify this issue before it affects the image in a way that would be noticeable.

 

This still gets back to the point that you can simply measure the data being transmitted through the cables to compare. These high end cable manufacturers don't publish any numbers indicating that they produce less errors than other brands. They'll tell you why the cable is better, but don't offer any proof and the specifications don't indicate anything other than meeting the required specifications for HDMI standards.

 

post #217 of 338

This is all nice and fine..

 

But it still doesn't answer my question.

 

It seems that there are two statements going on here:

 

One is Either there is a connection, and a proper signal is displayed, or it's not.

The other is that with interference, there is still a signal, just distorted...   But there's still image displayed, just improperly ...

 

If my understanding is correct here, the shielding is designed to address these interferences.

 

 

Is this correct?

 

post #218 of 338

 

Quote:
Originally Posted by Shotor102 View Post

This is all nice and fine..

 

But it still doesn't answer my question.

 

It seems that there are two statements going on here:

 

One is Either there is a connection, and a proper signal is displayed, or it's not.

The other is that with interference, there is still a signal, just distorted...   But there's still image displayed, just improperly ...

 

If my understanding is correct here, the shielding is designed to address these interferences.

 

 

Is this correct?

 


Not distorted. According to ac500 the missing pixel is colored with an average of the other pixel's shading, which makes it virtually undetectable even if that mistake was there for more than a few thousandths of a second.

 

As to answer your question, I don't know. In that scenario I see a difference, and yet I know there's no scientific explanation for that difference to exist. And I see that difference consistently in several blind tests where the placebo variable is nullified. I don't think this scenario is possible, but for the sake of hypothetical questions, I guess I would have to assume something was going on, that indeed the cable was producing a different quality image. It's not that I trust my own sight more than science, but simply my observations through a blind test are as objective as possible.

post #219 of 338
Quote:
Originally Posted by LizardKing1 View Post

 


Not distorted. According to ac500 the missing pixel is colored with an average of the other pixel's shading, which makes it virtually undetectable even if that mistake was there for more than a few thousandths of a second.

 

As to answer your question, I don't know. In that scenario I see a difference, and yet I know there's no scientific explanation for that difference to exist. And I see that difference consistently in several blind tests where the placebo variable is nullified. I don't think this scenario is possible, but for the sake of hypothetical questions, I guess I would have to assume something was going on, that indeed the cable was producing a different quality image. It's not that I trust my own sight more than science, but simply my observations through a blind test are as objective as possible.

 

Thanks for replying accordingly to my hypothetical question.  To be honest, that's all I really wanted to know in that regard.

As I previously stated, on blind tests I've conducted in my scenario, with the Plasma TV I could tell which was the brand name cable, and which was the cheaper no name brand. But with LCD's it was a bit more tedious. I could still see something, but it wasn't as relevant. And since the quality itself and the difference was so insignificant, I never kept the cable. Trust me that I don't just buy expensive brand name products for the sake of it, or because company x or company y says this and that.  If this was true, I would be perusing the streets with Beats Studios or SkullCrushers or something like that. But I don't, I peruse the streets with my SRH440 monitors and look like a complete tool... But I don't care.

 

As for ac500's post.. I've personally seen just how badly distorted poor HDMI connection or signal looks like.  Snowy/Artifacts/color bleeding/poor audio video sync/pixalation issues and blockiness..  and that's just to name a few...

 

So my question, again, is the HDMI technology is as simple as 'Either there's a signal and it's properly displayed, or there's not' 

 

Or

 

Is there more to it than that.

 

I would like a straight answer, no circular answers or beating behind the bush.

 

 

 

 

 

 


 

 


Edited by Shotor102 - 2/28/12 at 2:33pm
post #220 of 338
Quote:
Originally Posted by Shotor102 View Post

This is all nice and fine..

 

But it still doesn't answer my question.

 

It seems that there are two statements going on here:

 

One is Either there is a connection, and a proper signal is displayed, or it's not.

The other is that with interference, there is still a signal, just distorted...   But there's still image displayed, just improperly ...

 

If my understanding is correct here, the shielding is designed to address these interferences.

 

 

Is this correct?

 



If you read again, I answered your question exactly as you wanted. To say there is either a signal or not is not correct. The end receiving the signal is supposed to detect when the signal is problematic and should indicate that the cable is not properly connected before creating visible errors. Even with a faulty cable, there's a decent chance some signal is still making it from the source to the receiver unless the connection is just completely severed at some point. If there was absolutely no error detection or correction, then I'd imagine the TV's might still attempt to display something and would create a lot of the errors you described. I believe seeing these errors is a combination of the TV failing to react to them and the HDMI cable having issues with transmitting the signal.

 

-There is likely always a signal unless a cable has completely failed

-There is likely a physical connection with data being transmitted (assuming the cable is plugged in)

-The TV is supposed to detect errors and correct for them or determine that there is a problem with the connection

-This doesn't necessarily always happen, so it is possible that a faulty connection causes issues with the image

 

So:

-There is either an acceptable connection/signal or not. Whether or not the TV correctly detects and responds to it is not guaranteed.

post #221 of 338
Quote:
Originally Posted by CC Lemon View Post



If you read again, I answered your question exactly as you wanted. To say there is either a signal or not is not correct. The end receiving the signal is supposed to detect when the signal is problematic and should indicate that the cable is not properly connected before creating visible errors. Even with a faulty cable, there's a decent chance some signal is still making it from the source to the receiver unless the connection is just completely severed at some point. If there was absolutely no error detection or correction, then I'd imagine the TV's might still attempt to display something and would create a lot of the errors you described. I believe seeing these errors is a combination of the TV failing to react to them and the HDMI cable having issues with transmitting the signal.

 

-There is likely always a signal unless a cable has completely failed

-There is likely a physical connection with data being transmitted (assuming the cable is plugged in)

-The TV is supposed to detect errors and correct for them or determine that there is a problem with the connection

-This doesn't necessarily always happen, so it is possible that a faulty connection causes issues with the image

 

So:

-There is either an acceptable connection/signal or not. Whether or not the TV correctly detects and responds to it is not guaranteed.


I see..

 

 

Well, that's good enough for me.

 

post #222 of 338
You folks need to find something better to do than write long-form essays on HDMI cables...

I borrowed three HDMI cables from the Cable Company for free to try between my Perfect Wave DAC and Perfect Wave Transport, ranging in price from $200 to $500. I already own a PS Audio Perfect Wave HDMI cable. I thought the Wireworld Platinum Starlight might have had better bass than the free one that came with my Oppo, and the Harmonic Technology cable sounded a bit distorted. But the differences were minuscule. I do hear significant differences in interconnects, power cords, headphone cables, and vacuum tubes, so I am not a member of the "flat earth" society when it comes to such things. Based on my admittedly flawed experiment, I would agree that all HDMI cables sound nearly identical, regardless of price.
post #223 of 338
Quote:
Originally Posted by minimus View Post

You folks need to find something better to do than write long-form essays on HDMI cables...
I borrowed three HDMI cables from the Cable Company for free to try between my Perfect Wave DAC and Perfect Wave Transport, ranging in price from $200 to $500. I already own a PS Audio Perfect Wave HDMI cable. I thought the Wireworld Platinum Starlight might have had better bass than the free one that came with my Oppo, and the Harmonic Technology cable sounded a bit distorted. But the differences were minuscule. I do hear significant differences in interconnects, power cords, headphone cables, and vacuum tubes, so I am not a member of the "flat earth" society when it comes to such things. Based on my admittedly flawed experiment, I would agree that all HDMI cables sound nearly identical, regardless of price.

 

Based of a 'flawed experiment'....  hmm...

 

And you stated that they sound NEARLY identical, but not exactly Identical.... ?
 

 

post #224 of 338

It's sad, this store called Fry's electronics had buckets full of Monster $40 HDMI cables on tables the other day,i guess they want to be more like best buy? $20 optical toslink, RCA connectors.......then i get to the speaker wire section and see RCA brand for reasonable prices and then on the bottom shelf non-descript generic speaker wire for cheap by the bushell. I was thinking "I bet that's the stuff real HT installers use, just won't tell anyone, they call it 'Super-HD cable', since it's cheap and all basically the same" tongue_smile.gif

 

Somebody posted on another forum, this guy just tried dressing up his speaker cables with Emotiva heatshrink and color coded jackets with bi-amping and Jazz (which i'm told makes no real improvement either) and some other guy said "You can make it as fancy as you want on the outside, on the inside you have some cheap 18gauge wire" popcorn.gifwhich made me wonder, how often do we know what's going on inside our components? Surely a lot of our goods have corners cut somewhere and use cheap components, but yet we think we can make things noticeably better with just one part of the component chain? On this speaker review some guy mentioned replacing the caps in a crossover to make the speakers sound better and he said "night and day" but how many of us would bother? Or know how to do something like that?

 

I also don't appreciate the lower picture settings they like to give the plasmas and questionable settings they use with the rear projection tvs, feeding it their crummy signal that's been split who knows how many times, it's quite sad, nobody knows how good those tvs can look in their own homes. But that's for another day...


Edited by Astrozombie - 3/5/12 at 3:52am
post #225 of 338
Quote:
Originally Posted by Magick Man View Post


Then it isn't a "spec" cable. I have $5 Monoprice HDMI cables, they work perfectly. In terms of performance, they're every bit as good as $1000 Audioquest.


Funny enough, only my monoprice cables have gone bad. I've ordered 7 of from them and 3 had to be sent for warranty replacement because they weren't properly soldered to the tang and the signal kept dropping out.


Edited by astrallite - 3/11/12 at 3:48pm
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