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What HiFi Throw Down The Gauntlet.

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pocketkitchen said:
I know a cheap cable will carry 4k. My point is about the engineering - i.e. the quality. There's an awful lot of crap talked in this area. However, I saw for my self last week a picture that had white flecks appear on it with one cable that allegedly met HDMI spec over a 3m distance and the white flecks disappeared with a better cable. Both cables were pretty cheap - i.e. less than £20. White flecks appearing on a picture is directly related to bandwidth but usually only appears over longer distances. Could have been anything - a poor plug, irregular twisted pairs in the cable, a kink somewhere; who knows. However, buying the cheapest isn't very wise in something as complicated as a video distribution system of the kind that many hifi dealers have now branched out into. Also, please bear in mind that many things won't do what they promise, such as the HDBaseT switches that promise to carry 4k when the clock speed of their HDMI input chip clearly means that it's impossible for them to do so.

Finally, as a Blu-Ray player is allowed to lose 30% of the data by the HDMI standard which funnily enough, they never publicise, then if you have a Blu-Ray player which is not a particularly good sample then you only have 20% data to play with before you reach the 50% threshold beyond which the receiving equipment can no longer interpolate the missing data - no picture. None of this is foo, just good design. I'm suspicious of uber-expensive digital cables myself, but to simply buy the cheapest because it's all just ones and noughts is nonsense.
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My actual EXPERIENCE too!
 
Alan Sircom said:
Both a blue suit and a grey suit have similar levels of reflectivity and/or light absorption, but under double-blind conditions there is no identifiable difference between a dark suit and a bright pink suit with leopard skin lapels. I guess I could just go with what I think suits me, but that sounds dangerously subjective.
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Yes Alan, the suits will indeed not look different if you can't see them. They might smell differently though, be careful with that.

Is this some sort of budding idea for a new double-deaf test for audio equipment? Or something like Knob Feel?
 
pocketkitchen said:
I know a cheap cable will carry 4k. My point is about the engineering - i.e. the quality. There's an awful lot of crap talked in this area. However, I saw for my self last week a picture that had white flecks appear on it with one cable that allegedly met HDMI spec over a 3m distance and the white flecks disappeared with a better cable. Both cables were pretty cheap - i.e. less than £20. White flecks appearing on a picture is directly related to bandwidth but usually only appears over longer distances. Could have been anything - a poor plug, irregular twisted pairs in the cable, a kink somewhere; who knows.

I'm suspicious of uber-expensive digital cables myself, but to simply buy the cheapest because it's all just ones and noughts is nonsense.
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Yes it's possible for things to be badly made etc. Personally if I ever had one with sparklies, I would replace it. Last time I bought one I got amazon basics on the assumption that it was likely they would buy in bulk and monitor quality, and if there was a problem they would doubtless replace.

The critical point though though is that you can't improve on the picture transmitted by a non defective/damaged cable.

Quite how much one is prepared to pay for an assumption of higher quality for 1-3 m of open air cable is a matter of personal taste. If there is a cable one in the box, why would one even think of buying another unless it turns out to be defective?
 
If a certain percentage of missed data being interpolated is part of the spec (claimed in post 80) it puts a different shine on the matter from my point of view.
 
Alan Sircom said:
Seeing as how the alpha nerds are all gathered in one place, I'd like to ask a question:

I am going to a formal dinner tonight and I am not sure what suit colour is formal enough?

Both a blue suit and a grey suit have similar levels of reflectivity and/or light absorption, but under double-blind conditions there is no identifiable difference between a dark suit and a bright pink suit with leopard skin lapels. I guess I could just go with what I think suits me, but that sounds dangerously subjective.

Similarly, if I am offered a choice of foods, I am concerned about precisely how should I select what I eat, given that I will be unable to send the combustible produce off for laboratory analysis during the meal. This means that I may have to rely on my own decision-making process to extract the correct nutritional value from the meal, and I understand that our sensory mechanics are extremely unreliable, so I may find myself faced with a prawn when a tomato is called for. How do you cope in such a scenario?
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Ask your wife about the suit. Most blokes have no idea at all when it comes to the appropriateness or suitability (ha!) of suits. wrt food, go for the veggie option.
 
darrenyeats said:
If a certain percentage of missed data being interpolated is part of the spec (claimed in post 80) it puts a different shine on the matter from my point of view.
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It's intriguing but I'm not sure I know what it means exactly. Can anyone find a reference which can expand on it.
 
pocketkitchen said:
Finally, as a Blu-Ray player is allowed to lose 30% of the data by the HDMI standard which funnily enough, they never publicise, then if you have a Blu-Ray player which is not a particularly good sample then you only have 20% data to play with before you reach the 50% threshold beyond which the receiving equipment can no longer interpolate the missing data - no picture.
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I must look into this as I've not heard mention of it before.

I'm suspicious of uber-expensive digital cables myself, but to simply buy the cheapest because it's all just ones and noughts is nonsense.
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I'd buy the cheapest on the basis that once it works it'll be as good as the most expensive in terms of audio/video quality.
 
maxflinn said:
I'm on no more of a crusade than anyone else, pro or anti-Foo, so unless you're going to offer the same advice to the next person that starts a pro or anti Foo thread then please don't feel the need to give me any more of your 'special attention'.

Thanks.
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This is on your PFM public profile!!!!

'Interests
Fighting Foo

Occupation
Foo Fighter'

Crusader! Guilty as charged.
Pure comedy gold since you have almost no hifi experience!
 
adamdea said:
It's intriguing but I'm not sure I know what it means exactly. Can anyone find a reference which can expand on it.
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Here we go
http://arstechnica.com/civis/viewtopic.php?p=6271817
There is forward error correct, aiming to get 10-9 error rate, which is negligible.
This is NOT interpolation and the output is error free, so shoddy cable is going to have the usual "digital cliff" where at a certain distance it very abruptly becomes unusable
 
I offer my latest summary:
1. HDMI protocol has error correction.
2. The error correction sometimes fails.
3. If it fails, there is no re-transmission of the data. Therefore, you get a sparkly pixel. Several field reports suggest this does occur, with long runs and/or electrically noisy environments.

(3) is where HDMI differs from a "network" (typically TCP/IP these days). Networks re-transmit when error-correction fails. Therefore, a traditional network is technically superior to HDMI - score to the subjectivists.

No-one, yet, has reported a test showing measurable issues with HDMI or async USB like they have for coax S/PDIF - score to the foo fighters.

In USB audio, we have a similar situation to HDMI, I believe (correct me if I'm wrong). Some members here say that any dropped samples would be accompanied by audible clicks or problems (Max) and some members say many dropped samples would not cause an audible issue (Paul R).
 
formbypc said:
Why might it be 'helpful' ?
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Blue Jeans Cable are the only HDMI cable retailer and manufacturer in the States, the rest buy theirs from China (http://www.bluejeanscable.com/articles/where-does-hdmi-cable-come-from.htm?hdmiinfo), and are very open about the fact that once working - in terms of audio/video quality, all HDMI cables are the same.

I just thought that anyone undecided about HDMI cables, whether expensive ones give you better audio/video quality, etc, might like to read what an actual HDMI cable manufacturer has to say.
 
maxflinn said:
Blue Jeans Cable are the only HDMI cable manufacturer in the States, the rest buy theirs from China, and are very open about the fact that once working - in terms of audio/video quality, all HDMI cables are the same.

I just thought that anyone undecided about HDMI cables, whether expensive ones give you better audio/video quality, etc, might like to read what an actual HDMI cable manufacturer has to say.
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So .... why not just say so straight away ... ?
 
Max, the ability of a Blu-ray to lose that much data was news to me too and I discuss HDMI at work a great deal! The information was given to me by a member of the team that wrote the spec for HDMI 2.0. However, I'd be very surprised if the information was allowed to come out in any official form given the manufacturers behind HDMI include several of the main hardware manufacturers.
 
darrenyeats said:
I offer my latest summary:
1. HDMI protocol has error correction.
2. The error correction sometimes fails.
3. If it fails, there is no re-transmission of the data. Therefore, you get a sparkly pixel. Several field reports suggest this does occur, with long runs and/or electrically noisy environments... (Paul R).
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My point is that there is no interpolation like CD Audio has. This means that errors will cause clicks or mutes, not some subtle degradation, which is an excuse given by some of the exotic cable proponents.
Once a cable is good enough to eliminate the sparklies, going 10x more expensive is going to have no further benefit. The human eye is probably much better at spotting sparklies than hearing the odd glitch in audio
 
Well it's post 80 that suggests there is interpolation in HDMI. If this were true, it would suggest sparkles are actually due to a sequence of dropped samples, since isolated dropped samples would be unobvious.
 
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