Don't waste your money on high-priced HDMI cable

[baijuxavior]

Though I am not a seller either but I do second your opinion esp wrt MX cables & connectors. The perfect via media between 'hoi-polloi' hi-end & 'Cheap Chinese' stuff. Their HDMI ver 1.4 has swivel plugs that enhance durability against otherwise unavoidable cable twist. Moreover, its available in 2 lengths 1.5m & 3m. An absolute no-brainer, ALL these MX cables (incl ofc/non-ofc spkr/hdmi cables)Best of all, they make great stuff to suit all kinds of pockets. Would recommend all but the most finnicky audiophiles to stop looking elsewhere at all for all their cable& connector needs.
Regards

Trittya you posted the same eight times. Any problem?

 

[Thad E Ginathom]

A bad attack of jitter?

 

[Bluu]

A bad attack of jitter?

LOL!

Typical.

 

[baijuxavior]

A bad attack of jitter?

hyeah:hyeah:hyeah:

 

[Thad E Ginathom]

In the meantime, I've been reading it up. Comments from the more technically-minded most welcome, but it seems that the only thing that can save you from jitter is your DAC, or rather the jitter-correction section thereof.

 

[prankey]

With respect to coax digital, it has got more to do with 75 ohm compliance than anything else. Most coaxial cables are not 75 ohm. Even among those that are, different coaxial digital cables unfortunately do impart a tone to the sound. Why it happens, I do not know! Whether its loss of bits or not, I'm not sure either. However I'm pretty certain I'd be able to identify my current digital cable over a generic 50 rupee coaxial cable 9 times out of 10 in an A/B/X.

I speak from BOTH EXPERIENCE and KNOWLEDGE.. KNOWLEDGE is VERY IMPORTANT to derive the right conclusion out of EXPERIENCE! I have seen many posts here where we derive WRONG conclusion out of EXPERIENCE which is not the right way of interpreting things.

For once, I agree with what you and Murali have been trying to advocate about (to justify your high value purchase), however I have been using makeshift "coaxial" cables out of CHEAPEST CHINESE HEADPHONES! I used to cut the headphone 3.5mm jacked portion of a cheap Rs.10 cable and another portion of a Rs.10 RCA cable and just twist them together to get a Digital cable where those cable would perform WORST in ANALOG application. Infact I am still using such makeshift cables for my equipment when needed. I never observed any jitter or "lower quality audio" through this DIGITAL connection! I have compared such cables with high quality coaxial or optical cables and NEVER noticed any quality difference especially when compared with Analog LR Audio... Infact some of these cables developed loose connectivity and were loosing connection (drop in audio) randomly before I fix the "twist" (I accept that I do a SHODDY job of joining these cables!)...

Infact instead of using coaxial RCA connectors, I have even used regular 3.5mm pin cables to insert into the RCA ports and use another regular wire for ground (if common ground do not exist between equipment). I used to connect the ground any where in the chassis and still never faced "jitters" or "quality" loss! Please don't kill me for this approach, I love tweaking with my equipments to understand their tolerance limits.

Similarly, I have used different quality HDMI cables to compare quality, and never observed any difference like I see between HDMI and Component Video at the same resolution...

Gist - Even if some "Audiophiles" or "Videophiles" advocate and boost of their high value purchase of these cables, I have always believed that quality of cables HARDLY make ANY difference in quality of content (if ANY!) and hence is not worth spending more then the CHEAPEST OPTION AVAILABLE... The difference IF ANY observed is MORE HYPOTHETICAL than firm like we observe between analog and digital signals. Technically, if we do not observe jitters or drops in audio or corruption of video, there can be NO DIFFERENCE in QUALITY!!!

This is what Charles Hansen of Ayre has explained in another forum:

HDMI is an abortion of an interface that was crammed down our throats by Sony and Hollywood. Silicon Image was the party that made it all possible.

The idea by Sony was to have the audio and the video both on the same cable, to avoid confusing the schmucks who buy their Sony TV sets at Best Buy and can't figure out how to connect it. Hollywood demanded "content protection", and it was decided that HDCP as developed by Intel would suffice. Silicon Image was determined to develop the silicon chips so that they could cash in on the cash cow.

Of the many problems associated with HDMI, the audio quality is totally handicapped for lack of -- a pin! They designed the connector before they finished designing the system. They didn't have enough pins to also have a master audio clock.

So with HDMI, the audio clock is derived from the video clock. For high-def TV, the video clock runs at either 74.25 MHz or 74.25 * (1000/1001) [thank you NTSC!!!]. The audio clock runs at multiples of 48 kHz. Of course, these are not related. So the receiver has a PLL to regenerate an audio clock based on instructions from the transmitter (source) telling it what to do.

The result is the worst jitter of any system yet invented. It truly sucks.

Much later, they added a thing called Audio Rate Control in HDMI 1.3a. This puts a buffer and the master audio clock in the receiver. Then commands are sent upstream on the CEC line telling the player to speed up and slow down as necessary to keep the buffer full.

The only people to use this are Sony (HATS) and Pioneer (PQLS), but both use proprietary implementations that prevent use with other equipment.

And the fee for using this pile of steaming dog dung? $30,000 per year in licensing fees. It's a beautiful world, no?

cheers.
murali

Murali, I thank you for this post educating us something some of us were unaware of.. However, again, this doesn't talk of difference in "quality" between different cables you have experienced.. This is a limitation of HDMI and Jitters if any in Audio due to out of sync clock can be easily heard especially thru headphones listening... You don't need to be Audiophile to observe jitters Talking about difference in video you have talked about, I do not see any relevance on this post anyway.

In the meantime, I've been reading it up. Comments from the more technically-minded most welcome, but it seems that the only thing that can save you from jitter is your DAC, or rather the jitter-correction section thereof.

Absolutely... When we talk of quality of DAC, that is what they can do through buffering and interpolation and jitters are easily detected by the DAC (like our EARS ) and hence are very easily corrected..

Talking of HDMI video, AGAIN, as there are always 2 INVERTED (BIT SWAPPED) copies of video content, its virtually IMPOSSIBLE that such mirrored copies will get corrupted both at once and will still remain undetected by the receiver (TV or AVR). Hence, till we see the video, we should be getting 100% replica of original without any possible quality loss both in terms of Audio or Video.

 

[trittya]

Yes indeed, there was a problem because those multiple posts were posted by way of system error and not human error. Mods please do help in deleting. I was travelling by rail, passing thru UP, using aircel gprs when this happened, causing so much undue embarassment. The phone browser kept showing connection error all the time save once/twice but the posts kept piling up. When I tried to edit/delete multiple posts, it would either get posted again or it'd say that this is a duplicate post and would redirect me to the thread with yet another multiple post on the thread. I m now using airtel, so hope it doesn't happen again. Inconvenience deeply regretted. Regards, All.

 

[Thad E Ginathom]

It happens... nobody would have thought you did it intentionally.

It's just funny that it happened on a thread in which data integrity is a core issue

 

[baijuxavior]

Yes indeed, there was a problem because those multiple posts were posted by way of system error and not human error. Mods please do help in deleting. I was travelling by rail, passing thru UP, using aircel gprs when this happened, causing so much undue embarassment. The phone browser kept showing connection error all the time save once/twice but the posts kept piling up. When I tried to edit/delete multiple posts, it would either get posted again or it'd say that this is a duplicate post and would redirect me to the thread with yet another multiple post on the thread. I m now using airtel, so hope it doesn't happen again. Inconvenience deeply regretted. Regards, All.

This had happened with me too when browsing through gprs.

It happens... nobody would have thought you did it intentionally.

It's just funny that it happened on a thread in which data integrity is a core issue

hyeah:hyeah:

 

[square_wave]

If the DAC indeed drops out of synchronization, we'll completely lose the audio output for even seconds until the recovery happens. This is nothing but sync-loss. This is known and is not the point of debate. The point of debate is whether any medium induced jitter (if at all) will affect the final tonal quality when the DAC is still in synchronization. Until proven otherwise with supporting theory (not placebo), I'd like to believe the answer is NO.

Jitter and other vagaries in digital audio are very much a problem in accurate audio reproduction. Assembling a digital audio playback system which can create music is not an easy task ! The moment one gets into realtime reading of data of a spinning disc, you open a can of worms. How many worms you can see completely depends on the resolution of your system and your listening experience.

 

[prankey]

Jitter and other vagaries in digital audio are very much a problem in accurate audio reproduction. Assembling a digital audio playback system which can create music is not an easy task ! The moment one gets into realtime reading of data of a spinning disc, you open a can of worms. How many worms you can see completely depends on the resolution of your system and your listening experience.

I completely agree with you.. However, here people are disputing AV "quality" which can not change even when jitters come and get noticed/unnoticed... Also, there is one very important point we are missing in terms of jitter - clock synced or not, digital audio always have a reference sampling frequency using which the receiving DAC process bits... There are 2 facts here some of the more "experienced" audiophiles and videophiles are missing:

1. Lower quality cable can NOT be related to randomly delayed or jittery transmissing... ALL cables have the capacity to transmit data at a particular rate.. Till the data rate is below that limit, cable quality should not fluctuate the rate at which data is being transmitted at a noticeable rate. Also, any decent DAC will know if a bit is repeated or is delayed and hence should be able to fix such jitters...

2. Talking of data integrity, there is VERY HIGH TOLERANCE level in terms of loosing data integrity which in almost any WORST situation will still be maintain due to the fact that even a significant difference in voltage at the reception will still not compromise the integrity of DATA!

 

[Hiten]

Posting links and brief summary of their findings. I think we can trust CBC, CNET, BBC, & HDguru reviews.

Canadian Broadcasting Corp. Confirms HDMI Cable Scam! | HD Guru

The findings, all three HDMI cables tested reproduced every single pixel of the HDTV source.

CNET Quick Guide: HDMI and HDMI cables - CNET Reviews

Absolutely not--those cables are a rip-off. You should never pay more than $10 for a standard six-foot HDMI cable.

BBC - Newsbeat - Are expensive digital HDMI cables better?

"The cable itself isn't contributing to the quality of that picture at all. It is just moving it from one place to the other. It's the electronics at both ends that do the hard work."

HDMI Cable Makers and Dealers Use Misleading Labels to Push Needless Expensive Upgrades | HD Guru

buying a more expensive HDMI Hi Speed cable , regardless of labeling or what a salesman tells you will not give you any improvement in picture quality

If you still don't believe it here is how hdmi scam works
How the HDMI cable scam works

Regards

 

[stevieboy]

Thanks for collating all those links Hiten. Very useful! When I do get an HD TV I know what to buy. Especially since I'm more into audio than video and not too particularly analytical. Till then I'll just enjoy my hi-speed HD valves which operate at 480 Hz not 120 and have rareanium filaments

Regards

EDIT: Found this useful link too that suggests that at longer lengths, problems can occur with badly made cables.
http://gizmodo.com/268788/the-truth-about-monster-cable-part-2-verdict-cheap-cables-keep-upusually
http://gizmodo.com/gadgets/field-notes/the-truth-about-monster-cable-266616.php

 

[Thad E Ginathom]

EDIT: Found this useful link too that suggests that at longer lengths, problems can occur with badly made cables.

Problems can occur with badly-made anythings!

As I said before, we, the hifi-buying community, with our progress through more expensive (and probably often genuinely better) speaker cables and interconnects have set ourselves up good and proper. We have mentally conditioned ourselves.

In this country, at least, it would probably be a lot better for our health, safety and continued musical pleasure, if we translated that into a bit more concern for our house wiring, rather than fussing over digital cables!

 

[Hiten]

Till then I'll just enjoy my hi-speed HD valves which operate at 480 Hz not 120 and have rareanium filaments

Digital guys will never understand how much good analogue/tube/vinyl sounds. They worry about minute clock jitters and we enjoy sweet sweet 2nd harmonic distortions of tubes. So in a way we are forgiving, unbiased, practical, down to earth, music lovers.

 

[murali]

Problems can occur with badly-made anythings!

As I said before, we, the hifi-buying community, with our progress through more expensive (and probably often genuinely better) speaker cables and interconnects have set ourselves up good and proper. We have mentally conditioned ourselves.

In this country, at least, it would probably be a lot better for our health, safety and continued musical pleasure, if we translated that into a bit more concern for our house wiring, rather than fussing over digital cables!

For those who wish to continue this thread, here is what a physicist (not me)is saying:

cheers.
murali

How often have you heard this?
Its digital, so its 1s and 0s. That means there cant be any errors or distortion. You either get the signal perfectly or you dont.

For someone who knows little about electronic systems, this would sound perfectly logical and true. In reality its a rather nave way of thinking and it completely over simplifies the complexity of the world (and of physics). To show you why this statement is a lie, we need to go slightly into electro-magnetic physics. Dont worry, not too much, but just enough so that we can see how digital transmission, and in particular, a thing called channel coding (and digital coding in general) works.

The Digital Signal
The digital signal is often classified as an array of 1s and 0s. This is true in the logic sense we represent them in 1s and 0s. However theyre merely symbols. We could easily represent them as Xs and Ys or apples and oranges. In the real world, the digital signal is encoded and transmitted as a variety of alternating bits. This is usually a high and low signal. The signal is always encoded to minimise the probability of error for a given channel at its signal power limit. With all signals, there is a chance of noise (because, as you would of course know, anything in the real world is essential analogue, not digital).

Bandwidth
When we picture the transmission of a digital signal, we usually think of it in the way of the following:




Theorical Digital Signal
This is true in theory, and for higher level applications such as computer programs, controllers, etc. this is enough. In real life, the same digital signal (especially during transmission) looks more like this:


Real Life Digital Signal
Why is this? Because unfortunately the real world isnt as simple as on and off or high and low. Almost every communication channel (e.g. a cable, optical system, radio transmission) has a finite bandwidth. What is bandwidth? Thats the maximum speed that we can transmit data. I.e. theres a limit to how fast we can switch from 0 to 1 or 1 to 0. When we put a signal with more bandwidth than the channel can handle, the signal will not come out the same shape. How differently the shape changes depends on the nature of the system and the signal. However, take it from me that when you put in a perfectly square digital signal like that of the first diagram, youre most likely to get a real life signal like the second diagram.

The Bandwidth vs Cost Tradeoff
Engineering is often more about compromises than anything else. While we can build every network, cable, radio transmission mast with a huge amount of power to increase their bandwidth, it is not efficient. Generally theres an acceptable number of errors we can take for a particular signal. For example, most people would be satisfied with a TV signal that works 97% of the time for 97% of the population. To achieve the extra 3% coverage, by nature, may cost double the investment in resources. Hence, it is generally not worth spending so much money to get perfection.

A digital signal, therefore, is usually designed to be optimised in terms of resources used. A good designer of a product would attempt to use the least amount of resources to achieve a satisfactory outcome. So if we talk about bandwidth, it would mean that we would use the minimum bandwidth to still achieve signal recognition to a satisfactory level.

The Eye Diagram
Heres a concept that may interest those with a deeper understanding of probability and physics. When we pass a digital signal into a bandlimited channel, the signal is distorted. The receiver system will attempt to guess what the transmitted signal is. Lets use a numerical scale where -1 is 0? and 1 is 1?. How would the system guess? Simple: if the received signal is more than 0, we assume the transmitted signal is 1?. Otherwise if its any negative number, we assume the original transmitted level was -1, and the transmitted signal was 0?.

So in this instance, as long as no signal is distorted to the point where the signal crosses 0, we will still get an error free transmission.

The eye diagram is a diagram where multiple digital bit signals are laid upon one another. We can then see the variance in signal levels that occur to each bit, and see where they vary. The eye is the gap between the 1 and the 0. The gap therefore needs to exist in order for the receiver to be able to detect whether a signal is 1 or 0.


Eye Diagram
Here we have an eye diagram. We can see the most probable bit locations as the darkest areas. The eye is the two gaps which is formed by the two bit signals shown. As the signal becomes more distorted, the width of the signals increase (probability of error increases) and the eye starts to close. The point where the eye is completely closed is the point where the digital signal is distorted to the point of pure noise (no useful information can be extracted).

Most systems are designed with eye diagrams similar to that above. Theres little chance of error. However, errors still occur. We can still see a few bits getting rather close the center of the eye. These are the bits which are likely to cause error bits.

What Does All This Mean?
This means that any commercial product (i.e. a product designed to make money) will be designed to optimise for cost as well as performance. If we talk about say, a HDMI cable, we would expect that any cable more than a very short length will expect to have a more than negligible probability of error. Generally speaking, with most digital signals theres always a chance of error. When an error occurs, it doesnt mean that you wont get a signal at all. It just means that theres an error. These could be single bit errors which may be visible and uncorrected, or may be corrected depending on the mechanism. However errors exist, even though you may not know about them. Digital is far from perfect.

Going back to the HDMI cable, lets assume that the cable is now quite long. This means that the bandwidth is reduced. Performance is reduced because bandwidth is reduced and more errors can now occur. A badly made HDMI cable therefore shows much more significant errors. (People say that digital signals are perfect, yet its no secret that long HDMI cables can have problems. Why doesnt anyone question this?)

Channel Coding
Heres more proof that digital is not perfect. Channel coding is a study of the logics behind digital transmission. How do we best encode digital signals to ensure that the transmission has the best probability of success, and uses the least resources?

Channel coding exists everywhere. Lets talk about one common place you might see this in action your CDs. Most people think about CDs as the forementioned perfect and distortion free transmission. But think about it: tiny specs of dust, scratches, imperfections exist on every CD. The bits recorded on a CD are also tiny, and a laser will have no chance in telling a piece of dust for something else. This means that no CD will ever play without distortion at the bit level. I bet most people dont know this fact.

However, theres good reason why you may have not known about this. The guys who made the CD, Blu Ray, HDMI, etc. were pretty smart. They used a number of methods of digital transmission called channel coding. In a CD, this consisted of interweaving bits of information, optimising the type of transmitted information, and using checking bits to ensure that when errors did occur, there was a high chance that it was corrected and/or a close guess was used.

How does this work? There are a whole heap of methods they use and I wont even scratch the surface. But let me demonstrate onevery basically. Lets take for example, a number we need to transmit over a channel. Lets say 17. In binary, 17 is 10001. Lets assume a one bit error occurs. Because there are 5 digits, we could get 5 possible errors 10000, 10011, 10101, 11001, 00001. Notice what these numbers equal: 16, 19, 21, 25, 1. A 1 bit error could result in a slight distortion (16 instead of 17), or a huge distortion (1 instead of 17). In fact, if transmitting numbers in this way, the magnitude of distortion varies with the number of digits transmitted. If we transmit a 256 bit number, we could get a massive error due to just one bit being incorrect.

The engineers behind this technology realised this and decided that it was better to encode bits which were close together (read about Hamming distance). What they did was formulate a number of bit sequences which represented the transmitted data, where the sequences were different in the same way that the data was different. For example, lets arbitrarily represent 16 as 1011, 17 as 1001 and 18 as 0001. Notice that the difference between 17 and either 16 or 18 is 1 bit, and the difference between 16 and 18 is two bits. They are of the same difference as that between the numbers themselves.

What does this mean?
This means that when a spec of dust distorts a bit on a CD, it may mean that instead of 25355, the CD reads 25356. During a track, you will probably not be able to hear this, but the distortion will occur much like analogue distortion will occur. Digital simply means that there is less chance of this happening.

Digital is undoubted much better than analogue in many ways, and without it we would not live in the same world that we do today. However, the technology behind digital is much more analogue than you think. Digital is far from perfect dont assume that just because something is digital, it would be distortion free.

 

[venkatcr]

Murali, I am not able to see the diagrams. Can you check?

Cheers

 

[murali]

Sri venkatcr,

I am sorry, sir, I also seem to have lost them. This was sent to me by a friend of mine who is a renowned physicist in an American university. If I succeed in getting them, I shall certainly post them here. All I remember was they were simple square wave diagrams. Of course, I am not an electronics guy, nor a physicist, but a simple engineer in the chemical field trying to understand the molecules in the oil industry, and even after three decades in this profession, I still find I know little. The only reason I returned here with a few posts is because of the sadness I feel when I find people debating not technically but delving into pseudofacts like a few trying to defend because they spent more on such things as cables. What one buys and how much one spends have no correlation to discussions on audio and video matters, I believe, in a learning forum like hifivision.

Nice to hear from you after a long time. Hopefully one day we meet.

Best regards.
murali

 

[stevieboy]

What one buys and how much one spends have no correlation to discussions on audio and video matters, I believe, in a learning forum like hifivision.

Very true Murali! Well said :clapping:

I personally couldn't care less about a digital cable, but the current discussion was just too interesting and I had to do some reading to figure out the truth! Very interesting reading indeed I must say and I've learnt quite a BIT (pun intended ) today.

Regards

 

[Thad E Ginathom]

Murali, I am not able to see the diagrams. Can you check?

Cheers

The Greatest Lie of the Digital Age | The Hi-Fi Page

As with so much, googling for a sentence leads one to the original

Sorry, but I think that prankey covers the subject far, far better. I don't know if he gets a gold "physicist" medal, or even a bronze "engineer" ID tag, but at least he doesn't fluff around the subject completely leaving out error detection and correction.

EDIT... In the light of day, I realise that I read this article quickly, at about 4.00am, two hours after I had already decided to go to bed, and didn't give it a fair chance. I don't know that I'll come to any different conclusions, but I will, at least, give it another look


Do quality HDMI cables make a difference? --- is from the same site. I think it actually makes better points, and I'd be interested in prankey's response to them --- please?

.