[Mad Mr H]

Hi,

I have now ordered my Silver Starlight Wireworld cables for my main Cinema room. For my TV room I ordered Van Damme HDMI cables.

I was originally going to order Chord and Wireworld.

I did take notice of those that claim the shorter cables make no difference and so changed from my original Chord to Van Damme - This represented a saving and for my TV room there is no real need for "Videophile" quality.

Why the Silver Starlight Wireworld? The main run is about 7 meters long, at this distance there are clear differences between the cheaper and more expensive ranges of cable.

I did actually also order matching Silver Starlight shorter cables - this will allow me to test side by side Van Damme, Wireworld, Cheap & FREE cables.

Free, Cheap and Van Damme are already here, Wireworld delivery on route .

[Apone]

Looing foward to your findings

[recruit]

I will be keeping an eye on this thread, what I will ask is to let Mad Mr H have his say and then comment on his finding's please

[Mad Mr H]

Well they won't just be my findings. I usually have a group of members here and we all look at what we actually see (or hear), we don't always agree, But we do respect each others opinions, If I find a better way for something I will always consider the change - Not every step is forward.

Wirewolrd cables are in transit to me .

I might consider getting some Chord cables in to compare after the initial tests are run, thats mainly for the longer run where I think most agree that every meter counts on an HDMI cable. (I will consider others that might be available from those present at the test and that will include ANY brand or price)

The long run (7-9m) will start as a single cable, There may be later tests using HDMI boosters that ALSO have a jitter reduction circuit, just a HDMI booster in my opinion is not the correct product.

[davepuma]

Where have all the other replies gone? Hardly fair that?!

[HDMIHead]

Originally Posted by Mad Mr H

Well they won't just be my findings. I usually have a group of members here and we all look at what we actually see (or hear), we don't always agree, But we do respect each others opinions, If I find a better way for something I will always consider the change - Not every step is forward.

Wirewolrd cables are in transit to me .

I might consider getting some Chord cables in to compare after the initial tests are run, thats mainly for the longer run where I think most agree that every meter counts on an HDMI cable. (I will consider others that might be available from those present at the test and that will include ANY brand or price)

The long run (7-9m) will start as a single cable, There may be later tests using HDMI boosters that ALSO have a jitter reduction circuit, just a HDMI booster in my opinion is not the correct product.

Let us send you our kit too... and we can compare???

[Alan Mac]

Originally Posted by Mad Mr H

Well they won't just be my findings. I usually have a group of members here and we all look at what we actually see (or hear)

For the findings of a subjective test to be credible, the test procedures / protocols used are of fundamental importance. Could you briefly outline the procedures to be adopted for your HDMI cable tests?

Alan

[Mad Mr H]

Originally Posted by Alan Mac

For the findings of a subjective test to be credible, the test procedures / protocols used are of fundamental importance. Could you briefly outline the procedures to be adopted for your HDMI cable tests?

Alan

Hi Alan,

In the past various side by side tests have been carried out in my cinema and 2ch audio system, These are all "Fun" days for those involved and the objective is always to prove the best of any equipment or cable within "MY" system. I accept that what is best for my system may not suit other systems.

Are there any tests you would like to see done ?

PLEASE NOTE there will be NO HDMI Audio tests run, this will be video only.


I have the following players here

HD DVD - XA1, XA1 with HD SDI modification, EP10, EP35, XE1

Blu Ray - Samsung BDP-S1000, Sony S1 with HD SDI modification, Panasonic BD10

There may also be a Denon 3800 Blu Ray player here

[JohnWH]

If possible screen shots of any differences would be appreciated, and would lend credability to any findings you make.

Cheers,
John.

[Mad Mr H]

The system used for testing will be as follows (subject to change as I tend to change kit rather often!)

HD players as listed in post above.

Players will have either 0.5m or 1.0m HDMI/HDMI output cables.

HD sources will then pass through a 4:1 HDMI switcher box. This box also has a DVI output option fitted.

A 7m cable will then link the 4:1 switcher to the scaler.

The scaler a "TVONE C2-7200" then sends the images out to two projectors - This is a dual engine scaler with the ability to separately control the two projectors - In "NORMAL" use in my system this scalar does "edge blending" and "24Hz to 72Hz" refresh rate changes from HD sources.

From the scalar a 1m and 3m cable link the scalar to a HDMI/RGBHV with gamma control conversion unit.

Currently the Barco Cine9 projectors (2500x2000 resolution, 180+Mhz bandwidth) are running RGBHV, but an optional DVI input card should be installed very soon (in both)



People might pick up on the fact that the main link to the projectors differ in length 1m and 3m - This should actually be an advantage as the same brand can be tested 1 & 3m in direct comparison. It is also possible to run the same length of 3m with ease.

A more direct route of HD Source to PJ with DVI input is also possible.



Side by Side tests in this system are easy and at the press of a button. Actual changing cables takes the time.


Again I can try most things BUT will be more happy to test items that will be of use in "MY" system .

[Mad Mr H]

Originally Posted by JohnWH

Hi Andy, And may I say what a terribly nice bloke you seem to be .

If possible screen shots of any differences would be appreciated, and would lend credability to any findings you make.

Cheers,
John.

Hi John,

Once "Quoted" your here to stay

Screen shots are possible - I have to say that when we tested a bunch of scalers here that screen shots did not really help. There was an obvious visual difference that we all saw, That did also include easy of use as well as visual quality.

The issue is that the screen most people view on their PC does not have the ability to represent the actual image. ALSO I have to say that screen shots in tests I have seen in the past have been manipulated to suit sellers etc.

I have no flag to fly here, I'm gonna enjoy the results, and use the best I find suited to my system. I am also open to the possibility that I see no difference at all and that maybe expensive cables are just jewelry for my cinema .

Andy H.

PS - Ironic that you miss spell "credability" , H runs and checks he has spelt his name right .

[MarkTaylor]

Given the highly subjective nature of these sorts of tests will there be any attempt to conduct blind testing or will you use any form of objective measuring equipment to substantiate the findings?

It would also help to support the findings if you named the 'cheap' cables you are using and the source of the 'free' cables as there are some cables that even those of us who are unconvinced of the claims for the high-end cables would not use.

One solution might be to take the offer from HDMIhead to provide you with their cables as they are a known quantity that many people have been recommending and using at the lower end of the price spectrum.

[Trollslayer]

Originally Posted by Mad Mr H

Well they won't just be my findings. I usually have a group of members here and we all look at what we actually see (or hear), we don't always agree, But we do respect each others opinions, If I find a better way for something I will always consider the change - Not every step is forward.

Wirewolrd cables are in transit to me .

I might consider getting some Chord cables in to compare after the initial tests are run, thats mainly for the longer run where I think most agree that every meter counts on an HDMI cable. (I will consider others that might be available from those present at the test and that will include ANY brand or price)

The long run (7-9m) will start as a single cable, There may be later tests using HDMI boosters that ALSO have a jitter reduction circuit, just a HDMI booster in my opinion is not the correct product.

It's not the way things are usually done in these forums but if anyone has access to a BERT (Bit Error Rate Tester) which is specialsied test equipment it may be possible to get measurements.
There are three main characteristics which affect cables:
1. Insertion loss - i.e. how much signal level reduction occurs
2. Dispersion - imagine two people at opposite ends of a tunnel and one shouts to te other - the sound is very 'echoey' because the sound travels along different paths thus arriving at slightly different times.
2. Jitter - same root cause as dispersion but with the effect that the edges of the signals are affected by the different paths, cancelling or reinforcing each other so it appears that signal jitters about in time.
In high speed cables if there are irregularities you can get 'lumped loads' causing larger reflections of the signal (think of a water pipe with a bend in and the resulting turbulence) which is why very thin or soft cables don't work well - they lose shape which is very important.

Generally, the digital receiver on equipment only cares if the overall effect of these is to prevent it seeing a signal at the correct time in order to sample it. Once this is done the data is purely digital.

Not sure if the clarifies or confuses things

[MarkTaylor]

Results from the BERT would be an interesting comparison of the cables performance but I'd love to have this sort of testing done in conjunction with a qualified ISF Calibrator as it is the visual effects of the cables on the display that are usually quoted.

Many of the results are usually expressed in terms of black levels and colour changes which would be extremely simple to verify if you started with a calibrated screen then observed if there were any measurable changes.

[JohnWH]

Originally Posted by Mad Mr H

Hi John,

Once "Quoted" your here to stay

Screen shots are possible - I have to say that when we tested a bunch of scalers here that screen shots did not really help. There was an obvious visual difference that we all saw, That did also include easy of use as well as visual quality.

The issue is that the screen most people view on their PC does not have the ability to represent the actual image. ALSO I have to say that screen shots in tests I have seen in the past have been manipulated to suit sellers etc.

I have no flag to fly here, I'm gonna enjoy the results, and use the best I find suited to my system. I am also open to the possibility that I see no difference at all and that maybe expensive cables are just jewelry for my cinema .

Andy H.

PS - Ironic that you miss spell "credability" , H runs and checks he has spelt his name right .

Hi Andy,

LOL, spelling, ppft, not a strong a point for me, I think use of apps with built in spell checking tends to make the brain lazy!

On the screen shots, the idea is to just show that there was a difference, I'd agree that you can't really use them to determin what looked best. When doing this at work I do occasionaly zoom in on the specific artifacts in question so that you don't get lost in the overall image. Its also possible to do some analysis on the images to determine if they're effectively the same, although I don't think this would come under the heading of "fun!

Cheers,
John.

[Mad Mr H]

Originally Posted by MarkTaylor

....will there be any attempt to conduct blind testing or will you use any form of objective measuring equipment to substantiate the findings?

Cables will be totally blind to the viewers - just called abc etc.

objective measuring equipment - our eyes .

It would also help to support the findings if you named the 'cheap' cables you are using and the source of the 'free' cables as there are some cables that even those of us who are unconvinced of the claims for the high-end cables would not use.

Will be named AFTER testing.

One solution might be to take the offer from HDMIhead to provide you with their cables as they are a known quantity that many people have been recommending and using at the lower end of the price spectrum.

As it happens a number of people have offered cables as well as those I just bought in, So there will be some "GUEST" cables from those that offered - I have decided to keep those names out of the thread - so it is as blind a test as I can make it.

[Mad Mr H]

Originally Posted by Trollslayer

if anyone has access to a BERT (Bit Error Rate Tester) which is specialsied test equipment it may be possible to get measurements.

that was done by one forum member who had to test 100+ cables. His results in his words were that there was no reason to use different cables.

However graphs seen showing the results clearly show different results - can that be seen? I dont know, I did not and wont be doing that test.

There are three main characteristics which affect cables:
1. Insertion loss -
2. Dispersion -
2. Jitter -

!

I got to say your explaination of the above three items does not in my opinion really explain each item correctly - But I get the idea of what your trying to say.....

Getting sligtly off topic here......

[Mad Mr H]

Originally Posted by MarkTaylor

I'd love to have this sort of testing done in conjunction with a qualified ISF Calibrator as it is the visual effects of the cables on the display that are usually quoted.

Many of the results are usually expressed in terms of black levels and colour changes which would be extremely simple to verify if you started with a calibrated screen then observed if there were any measurable changes.

Ah! now this might be possible.

My PET HATE on these forums is the people that offer ISF calibration services but DONT use ISF certified equipment.

I am NOT ISF certified, But my test equipment IS ISF Certified. So it might be possible to do this form of testing.

Sencore CP5000 ISF certified
Thoma (cant remember the number!)

The projectors will be re calibrated prior to this test, in the usual "Blended" projection system it is essential for the pair to be as identical as possible. The good news here is that CRT projectors dont change as quick with time as Digital lamp based projectors.

[MarkTaylor]

If you can do it, the potential exists for this to be the first and only test of its type that I've come across and it would certainly make a huge difference to the general utility of the results.

The old Mk1 eyeball is an amazing device but its ability to see what it wants to see at times is considerable so even if you only focused on black levels with the Sencore it would be a very useful test as people often comment on changes in this aspect when comparing cables.

It would be very good if we could move on from the long running 'oh yes they do, oh no they don't' debate as if you can show measurable differences we can start exploring why rather than just arguing about the theoretical impossibility of the difference

[Mad Mr H]

Originally Posted by MarkTaylor

If you can do it, the potential exists for this to be the first and only test of its type that I've come across and it would certainly make a huge difference to the general utility of the results.

Sold to me Sir! Colourimeter tests are possible and can be done here, they take time.

My Sencore allows charting of the products so thats an area I am happy to try.

The old Mk1 eyeball is an amazing device but its ability to see what it wants to see at times is considerable

I agree, And the old Brain and Mouth in conjunction with the eye are a powerful force of persuasion

so even if you only focused on black levels with the Sencore it would be a very useful test as people often comment on changes in this aspect when comparing cables.

This is where the CRT projector excels at - Black levels, So should be a good test.

It would be very good if we could move on from the long running 'oh yes they do, oh no they don't' debate as if you can show measurable differences we can start exploring why rather than just arguing about the theoretical impossibility of the difference

progress .

[Alan Mac]

Originally Posted by Mad Mr H

Cables will be totally blind to the viewers - just called abc etc.

objective measuring equipment - our eyes .

How does your subjective test procedure establish whether the viewers taking part in the test actually can see a difference (between HDMI cables)?

It’s no good just asking them if they can see a difference, that does not prove anything.


Alan

[Mad Mr H]

Hi Alan,

What would you suggest ?

I would like to hear what people would like to be tested, Of course there are limits to whats available but lets start with your wish list.

Andy H.

[Alan Mac]

Originally Posted by Mad Mr H

Hi Alan,

What would you suggest ?

Andy H.

Andy,

I would like the subjective test (of whether different HDMI cables give different picture quality) to take the form of a double-blind ABX type test.

The two HDMI cables under test would correspond to pictures “A” and “B”, while picture “X” is the unknown and may correspond to either “A” or “B”.

The subject is free to select pictures “A”, “B” or “X” at will from their viewing position.

The subject attempts to identify “X”.
Is it “A” or is it “B” ?

The identity of “X” is then reset (by a computer program).
The subject then repeats the test for a pre-determined number of trials.

If the subject can correctly identify “X” with an adequately low probability of having just guessed the answers, then we may reasonably conclude that they can indeed detect a difference between “A” and “B”.


Alan

Last Monday The Gadget Show on Five.tv tested 2 HDMI cables, one was about £25 and the other was £125. There was no difference in quality at all. They reccommended going for the cheaper HDMI cable...

[mossym]

while definitely the way to run the test, that may be difficult to achieve.

agreed though, a 1 off, is that cable better than the last you saw is tough to sell as concrete proof.

[Mad Mr H]

Originally Posted by TheTiffy

Last Monday The Gadget Show on Five.tv tested 2 HDMI cables, one was about £25 and the other was £125. There was no difference in quality at all. They reccommended going for the cheaper HDMI cable...

I have checked the web site and cant find this test.

Please would you provide a link , What is importand here is the length of the cable and the bandwidth it is passing.

I think we all agree on that , and that the longer the cable the more the quality matters.

.............Your post is slightly off topic so please could you provide the link in another thread for others to comment. Thank you.

[Mad Mr H]

Originally Posted by Alan Mac

Andy,

I would like the test take the form of a double-blind ABX type test.

The identity of “X” is then reset (by a computer program).
The subject then repeats the test for a pre-determined number of trials.

Alan

Originally Posted by mossym

while definitely the way to run the test, that may be difficult to achieve.

agreed though, a 1 off, is that cable better than the last you saw is tough to sell as concrete proof.

OK, Firstly that double blind test is actually VERY easy to setup, So I will consider it.

This of course assumes that we can see a differance.

There is every chance (being open minded) that no differance is seen, If thats th case then no double blind test is available. I hope every one agree on that ?


Mossym - I have NEVER just done single tests of anything, to put this in perspective in "my world" of home cinema just over 150 hours were spent on colour balance of my two previous projectors - I am very patient and set out to achieve the best I can.

For those that have an hour to kill please read through my home cinema thread in my signature - That will give a better insight to the guy behind the name . You never know there might be something of use to you in there .

Originally Posted by Mad Mr H

I have checked the web site and cant find this test.

Please would you provide a link , What is importand here is the length of the cable and the bandwidth it is passing.

I think we all agree on that , and that the longer the cable the more the quality matters.

.............Your post is slightly off topic so please could you provide the link in another thread for others to comment. Thank you.

Apologies, I thought this was about whether different HDMI cables give different picture quality.

[Mad Mr H]

For the record..........

There are now FIVE well known brands of cables that will be included in the initial test (there might be a sixth I am considering that at the mo)

[Mad Mr H]

Originally Posted by TheTiffy

Apologies, I thought this was about whether different HDMI cables give different picture quality.

Sort of, but your post does not provide a link that I can see what was said and what was tested. So the result might be "buy £25 not £125 cable" but the situation is not mentioned.

Plasma tv, LCD, projector, source, resolution, distance, with audio, without audio, sure I missed some.

Im sure you meant your post to be informative but I hope you now see that we are missing the info related to the statement.

There are two main camps in this area of the forum, those that believe "most" HDMI cables give the same results and those that believe there is a visual difference.

There are many other trains of thought as well, but I think it fair to say ALL groups like to see full and transparent information to back up each statement.

General thoughts about this can be found in many existing threads.

This thread is slightly more specific in that I am not repeating what others have said, I am setting out to test IF there is a difference in MY system. My previous A/B testing did show a difference that others questioned so this time round I will try and offer more than just "thats what I saw" .