Importance of quality of HDMI leads

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The_Lhc

Well-known member
Oct 16, 2008
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aliEnRIK:my eyes will always be as good one day to the next

Well THAT certainly isn't true, my eyes have been getting progressively worse my entire life! I wouldn't be allowed to drive if I was still wearing the glasses I had 20 years ago!
 

aliEnRIK

New member
Aug 27, 2008
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the_lhc:
aliEnRIK:my eyes will always be as good one day to the next

Well THAT certainly isn't true, my eyes have been getting progressively worse my entire life! I wouldn't be allowed to drive if I was still wearing the glasses I had 20 years ago!

a barmy answer lhc

My eyes are as good today as they were 10 years ago ~ twenty twenty vision

If my eyes DO deteriorate they will take a LOT longer than the few hours/days it would take for me to differentiate between hdmi visual quality
 
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Anonymous

Guest
Interesting read (if you've got the time
)

http://www.audioholics.com/education/cables/long-hdmi-cable-bench-tests

Vid:
http://www.videojug.com/webvideo/tutorial-hdmi-cables-cheap-vs-expensive
 
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Anonymous

Guest
FrankHarveyHiFi:
I've been in a few cable debates on another forum, mentioning something that not everyone agrees on. Surprise surprise.

Getting the 0's and 1's to the other end is one part of the story, and many things can be measured at both ends. But what about those aspects of sound that can't be measured?

My point in the other threads was that many people said you can measure everything to show a difference, but my point was that if one product measured 0.001% distortion and another was 0.002% distortion, people aren't going to hear the difference. So if a measured difference can't be heard, does it not follow that certai non measurable difference can be heard?

Actually, with a digital signal, getting the 1s and 0s from one end of the cable to the other is the only story in town. There is nothing else being attempted and nothing else that matters. What happens at either end, from the equipment sending and the equipment receiving is another matter but if the HDMI protocol is followed as per it's specification, then there are no esoteric quirks, this is digital and anything else is a blatant attempt to inject speculation and doubt into the minds of non-technical consumers who might be taken in by it. Doing so sells high margin product, makes people "feel good" about their expensive purchase, but has absolutely zero effect whatsoever on whether there are other "factors" in digital transmission other than the actual transmission of noughts and ones. There aren't.
 

Alec

Well-known member
Oct 8, 2007
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FrankHarveyHiFi:

So if a measured difference can't be heard, does it not follow that certai non measurable difference can be heard?

In the nicest possible way i think just reading that, you can see that no, it doesnt follow. That doesnt stop it being possible that things affect the sound which we dont yet know about or we cant yet measure, or jsut havent measure properly.

Purely from a linguistic and loose philosophical perspective, you understand. Whether that could actually be the case scientifically speaking with particular regard to HDMI leads, i havent a clue.

Incidentally, the only explananation i have read that is understandable to a numpty like me is not in any of these totally useless threads, but on the qed site. If there can be a difference, however, still doesnt mean we will all be able to see it.
 

The_Lhc

Well-known member
Oct 16, 2008
1,176
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19,195
aliEnRIK:the_lhc:aliEnRIK:my eyes will always be as good one day to the next
Well THAT certainly isn't true, my eyes have been getting progressively worse my entire life! I wouldn't be allowed to drive if I was still wearing the glasses I had 20 years ago!

a barmy answer lhc

No it isn't.

My eyes are as good today as they were 10 years ago ~ twenty twenty vision

If my eyes DO deteriorate they will take a LOT longer than the few hours/days it would take for me to differentiate between hdmi visual quality

Ah but that isn't what you said is it? You said your eyes will ALWAYS be as good one day to the next. I'm simply pointing out that there's no way you can guarantee that.
 

aliEnRIK

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Aug 27, 2008
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the_lhc:aliEnRIK:the_lhc:aliEnRIK:my eyes will always be as good one day to the next
Well THAT certainly isn't true, my eyes have been getting progressively worse my entire life! I wouldn't be allowed to drive if I was still wearing the glasses I had 20 years ago!

a barmy answer lhc

No it isn't.

My eyes are as good today as they were 10 years ago ~ twenty twenty vision

If my eyes DO deteriorate they will take a LOT longer than the few hours/days it would take for me to differentiate between hdmi visual quality

Ah but that isn't what you said is it? You said your eyes will ALWAYS be as good one day to the next. I'm simply pointing out that there's no way you can guarantee that.

In the case for testing one hdmi against another my eyes will do just fine
 
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Anonymous

Guest
I have to fully back Will up on this one. Having a background in digital transmission systems and digital codec theory and practice in the telecoms space I also believe that a 1 is a 1 and a 0 is a 0 and there are no good and bad sounding 1's and 0's. Yes a cable can introduce interference and signal degradation if it doesn't contain suffient shielding or has poor attenuation characteristics, but as long as the receiving electronics can still see the 1's and 0's as they were sent from the sending electronics (taking into account the appropriate digital signal processing and effective management of quantization errors) then the only real differences in what you hear should be as a result of the electronics (DSP, DAC, amplification, etc.) at the sending/receiving end of the cable path and nothing more than that.

Having a far greater understanding of digital transmission systems than the average consumer I do have to question the value of high end digital interconnects when a simpler/cheaper design can transport the 1's and 0's intact within the signal path just as effectively.
 
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Anonymous

Guest
I tried an atlas hdmi against a game £10 hdmi last night on my xbox and there seemed to be a difference to me. Next time i have my mates round i will do test with them.
 
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Anonymous

Guest
aliEnRIK:the_lhc:aliEnRIK:the_lhc:aliEnRIK:my eyes will always be as good one day to the next
Well THAT certainly isn't true, my eyes have been getting progressively worse my entire life! I wouldn't be allowed to drive if I was still wearing the glasses I had 20 years ago!

a barmy answer lhc

No it isn't.

My eyes are as good today as they were 10 years ago ~ twenty twenty vision

If my eyes DO deteriorate they will take a LOT longer than the few hours/days it would take for me to differentiate between hdmi visual quality

Ah but that isn't what you said is it? You said your eyes will ALWAYS be as good one day to the next. I'm simply pointing out that there's no way you can guarantee that.

In the case for testing one hdmi against another my eyes will do just fine

did you do blind tests or side by side comparisons with exactly the same equipment save for the cables
 
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Anonymous

Guest
Chiswick:
I have to fully back Will up on this one. Having a background in digital transmission systems and digital codec theory and practice in the telecoms space I also believe that a 1 is a 1 and a 0 is a 0 and there are no good and bad sounding 1's and 0's. Yes a cable can introduce interference and signal degradation if it doesn't contain suffient shielding or has poor attenuation characteristics, but as long as the receiving electronics can still see the 1's and 0's as they were sent from the sending electronics (taking into account the appropriate digital signal processing and effective management of quantization errors) then the only real differences in what you hear should be as a result of the electronics (DSP, DAC, amplification, etc.) at the sending/receiving end of the cable path and nothing more than that.

Having a far greater understanding of digital transmission systems than the average consumer I do have to question the value of high end digital interconnects when a simpler/cheaper design can transport the 1's and 0's intact within the signal path just as effectively.

Thank you Chiswick. A bit of professional input is just what was required.
 

aliEnRIK

New member
Aug 27, 2008
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Im not allowed to post the link but ive seen a digital coax cable (Its ALL digital though isnt it
) where the 'jitter' was easily measured and it was even found that cables were directional (Jitter worse in one direction than the other on 2 of the 3 cables, the worst being bad either way)

It was also clearly audible to the guy who tested them

Food......for.......thought............
 
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Anonymous

Guest
noone else is talking about jitter in cables

besides before it even matters whether it exists in cables or not you have to workout at what point it becomes audible or visible and theres lots of conflicting info on that

besides which will and chiswick are right
 
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Anonymous

Guest
Yes, jitter is one of the issues that can and will affect digital signals, or more importantly the clocking of the square wave being carried by the cables, and yes significant jitter will become noticeable audibly as a result of the receiving DSP/DAC not interpreting the incoming waveform and therefore 1/0's correctly.

However this said. Jitter normally only really becomes problem and is likely to have audible impact over long distances (a good several meters plus) and/or if the data transmission rate is particulary high (several 100Mbit/s or several Gbps) in which case the clocking of the (square) waveform has to be so much more acurate to ensure that the incoming signals are correctly interpreted.

For shorter cable runs (up to a few meters) and for lower data transmission rates (less than most AV kit will produce/need) the main source of jitter is from the electronics at either end of the cable. A cable of up to a few meters would have to be pretty rubbish (and quite probably incorrectly made or badly terminated) to introduce any significant jitter that is then audible as a result.

However, if you are planning to run long cable runs of more than a few meters between your source components and the receiving devices then I would of course recommend higher quality cables, just to be safe.
 

Frank Harvey

Well-known member
Jun 27, 2008
567
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Will Harris:Actually, with a digital signal, getting the 1s and 0s from one end of the cable to the other is the only story in town. There is nothing else being attempted and nothing else that matters.So then the same could be said of a normal digital interconnect. And many will say that there are differences to be had there. There's always something else "in play".....


Does it also follow that ANY digital CD transport will sound exactly the same? They're all reading and passing on 0's and 1's, so they all sound the same right? Wrong. Anyway, I'm not going any further on a cable thread - I know where it leads!
 

carter

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Aug 27, 2008
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why would it make a differance what length it is if its just 1s and 0s why is a short budget good anough but not a long budget
 
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Anonymous

Guest
If the TX/RX electronics of a reasonably good quality, a good clocking source is used and the design of the RX/TX circuitry isn't especially prone or susceptable to the impact of jitter (however small) then there should be minimal-to-no audible and/or visual impact. Digital signals are a lot more robust than people think. That's why the whole world of data transmission has moved from analogue to digital transmission systems.

I would personally be far move concerned with the quality of the electronics at either end of the cable. I'd rather spend my money on a reasonably priced/quality cable and use the money to invest in better electronics on either end of the cable; and if you're really concerned about the impact of jitter, invest in electronics that include jitter reduction/reclocking/resyncing capabilities.

All this said, I am a big believer in the impact of quality analogue interconnects
 
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Anonymous

Guest
FrankHarveyHiFi:
Will Harris:Actually, with a digital signal, getting the 1s and 0s from one end of the cable to the other is the only story in town. There is nothing else being attempted and nothing else that matters.So then the same could be said of a normal digital interconnect. And many will say that there are differences to be had there. There's always something else "in play".....


Does it also follow that ANY digital CD transport will sound exactly the same? They're all reading and passing on 0's and 1's, so they all sound the same right? Wrong. Anyway, I'm not going any further on a cable thread - I know where it leads!

HDMI is quite different to SPDIF in how it's handled. It's more akin to networking than a one way stream which is what CD players put out over coax.

I think you know we'll have to beg to differ on the HDMI front. I'm with Chiswick on this. It's the kit at each end that'll determine how digital data is transmitted and received. The only thing the cable has to do is contain no defects in it's manuacture and be up to specification so the equipment at each end can get a clean signal. Analogue is another matter.
 
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Anonymous

Guest
nodnarb4444:why would it make a differance what length it is if its just 1s and 0s why is a short budget good anough but not a long budget

I'm not going into depth here as it's Friday evening and I should really be heading out to the pub by now. In short, over longer distances you get greater signal dispersion, which in simple terms means the square wave output by the transmit end of the signal path becomes less and less square as it travels along the cables. Higher quality cables would hopefully demonstrate lower attentuation characteristics meaning most of the output signal level and shape is maintained as it travels along the cable path. The longer the cable, the more likelihood you will suffer the effects of signal dispersion. If the signal is sufficiently degraded by the time it reaches the receiver at the far end of the cable, then the DSP/DAC will have trouble correctly interpreting the incoming data stream and this can result in incorrect decode/conversion which will/may result in audible/visual nasties.

Just quickly, to answer another point posed, CD transports will sound different. This will primarily be a result of their jitter characteristics. Again, this re-enforces what I've been saying all along. The quality of the electronics at the source and recieving end of the signal path is key.
 

aliEnRIK

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Aug 27, 2008
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Chiswick:
Just quickly, to answer another point posed, CD transports will sound different. This will primarily be a result of their jitter characteristics. Again, this re-enforces what I've been saying all along. The quality of the electronics at the source and recieving end of the signal path is key.

So by definition, if a cd/dvd or blurays transport is poor then its likely that a 'better quality' cable would help send the information intact whilst a poorly constructed cable would aid the 'jitter' in getting worse?
 

carter

New member
Aug 27, 2008
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Chiswick:

nodnarb4444:why would it make a differance what length it is if its just 1s and 0s why is a short budget good anough but not a long budget

I'm not going into depth here as it's Friday evening and I should really be heading out to the pub by now. In short, over longer distances you get greater signal dispersion, which in simple terms means the square wave output by the transmit end of the signal path becomes less and less square as it travels along the cables. Higher quality cables would hopefully demonstrate lower attentuation characteristics meaning most of the output signal level and shape is maintained as it travels along the cable path. The longer the cable, the more likelihood you will suffer the effects of signal dispersion. If the signal is sufficiently degraded by the time it reaches the receiver at the far end of the cable, then the DSP/DAC will have trouble correctly interpreting the incoming data stream and this can result in incorrect decode/conversion which will/may result in audible/visual nasties.

Just quickly, to answer another point posed, CD transports will sound different. This will primarily be a result of their jitter characteristics. Again, this re-enforces what I've been saying all along. The quality of the electronics at the source and recieving end of the signal path is key.

i think this is the bit that i dont understan so digital signals can lose qualaty
 

Alec

Well-known member
Oct 8, 2007
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aliEnRIK:one off:

the elves have a lot to do with it

With your labotomy?

No. With his lObotomy. If he's had one. I couldn't possibly comment.
 

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