Cat 7 Cable

[Thad E Ginathom]

Nikhil, There was no condescension intended from my side. Apologies if you felt any.

The questions asked were either relevant or analogy.

Many of us have areas of speciality. To some extent, but outdated (as I always admit) it is one of mine, but I'm a pigmy compared to the other knowledgeable guys who posted here. Being thus, in the middle, it is a good learning experience for me. It's been a good conversation for me: one of the best, because you shared ideas and possibilities without hitting anybody about anything. Hope we didn't hit!

At this stage, I'm wondering if the CAT-7 shielding would be effective in a mains duct. I'm not sure that that is the kind of thing it would be designed to protect against. I'm hoping that Asliarun or Ranjeet is going to offer something on that.

 

[Nikhil]

All is well Thad. It's all good.

I don't think the shielding would work in a mains duct personally but as I said earlier - would be really nice if it did. The alternative route has some other challenges like my UPS system, an AC unit and some wall AC outlets.

 

[ranjeetrain]

Reading through all the "new posts" on this thread: well, first of all, till first 15-16 posts, it wasn't even clear whether this query was for audio application. So there was no question of an attempt to take it south. I was merely trying to help and just kept addressing questions that kept coming in...

Anyway, here goes...

It would be nice to get a reference to this.
I have a very basic understanding of the TCP IP protocol/stack and nothing I know of says of this specifically.



Especially this part.

Nikhil, in a previous post you apparently admitted you understand TCP/IP "works". So a bit surprised to see this demand of "reference". Anyway, you can always look up IETF site for all things Internet. If you do need reference line-wise and interpretation wise, then you will either have to wait till I can find enough spare time to highlight specific parts from the protocol's official specification for your reference or you'll have to hire me. I can assure you if hired, I'll do it pretty quickly Alternatively, there is this thing called Google. I am sure you would rather type in Google TCP/IP specification. The pages it throws up will answer many more questions than this alone.

Could you guys clarify the crosstalk thing? I am under the impression that it is about interference between pairs in one cable, and not about external interference from other cables or sources.

Thad, when a cable reject/eliminates interference it just rejects it. It doesn't know whether the interference is from the wires rolling next to them, or from elsewhere. If the interference is weak enough to be contained by its shield, it remain unaffected, regardless of the origin of the interference.

I sort-of wish you'd put that in the first post! it is not wise. I don't know if best-practice recommendations have changed, but I suspect (Ranjeet and Arun will tell us) that they would still be to separate electricity and data runs, avoid fittings such as fluorescent lights, and when electricity and data must cross, do so at right angles.

It's been done to several steps further, Thad. You can actually send data packets through mains.

Look up "Powerline Adapters" or PowerPacket Technology. TCP/IP protocols are so robust they work even if directly mains lines are used as physical medium forget noise, interference, shielding

This page is a goor start-point.

I don't mind a good discussion but some of the questions asked (in the context of my original post) were to put it mildly .... condescending.

I am very surprised with this. Way too many times at this forum to keep a count, people have been asked - have you tried it?. Have you heard it? Do you own it? As if not owning, hot having heard or not having tried something was a disqualification from posting based on established academic knowledge and knowledge earned through indirect experiences. People have gone to lengths of declaring comments that were not based on personal experience as "unsubstantiated". I am really really surprised to read this appears condescending in this thread. May be it's time to have some clear understanding of what's condescending and what isn't. Because such things can't be condescending or non-condescending based on which thread it appears in, or where it comes from.

At this stage, I'm wondering if the CAT-7 shielding would be effective in a mains duct. I'm not sure that that is the kind of thing it would be designed to protect against. I'm hoping that Asliarun or Ranjeet is going to offer something on that.

Thad, what's the point going in for CAT7 if it has to be laid alongside mains cables? Definitely, if someone spends on shielded cables, he would be wise to keep it as far away from major sources of interference such as electrical lines. But that's just my 2 paise! Others might say, whats shielding good for, what am I paying for if I have to prepare another conduit.

 

[Thad E Ginathom]

I've come across the power-line stuff, and made a passing reference to it, but I supposed that there we are talking about a different physical mechanism.

 

[Santy]

Is the requirement to stream an audio file realtime via the CAT cable? I mean is it for a player to read an audio file from a remote/ network drive via the cable? Is it intended to avoid a Wifi streaming because it is complicated/ more expensive/ inferior? Sorry I am just being curious. I consider myself as a dummy when it comes to network audio streaming, be it wired or wireless.

 

[Thad E Ginathom]

Well, discussion of alternatives may not be welcome, and sure, it was not asked for. I had wondered whether to suggest why not wireless, but I didn't, partly because I feared a stream of responses about it sounding different, but more because I feel that wireless performance is impossible to predict, but can only be found out after one has spent the money. Number of walls/ceilings/etc. amount of iron work in each, angles through each.

But, if Nikhil runs his cable in a mains conduit, that can't be predicted either

 

[Nikhil]

I am running wifi at the moment. I have been recommended to use cable.
I was told that there is an improvement in the sound over using wifi.

However, a few people who used cable had issues with noise creeping into the system from secondary sources.
I guess its a matter of picking your poison.

Digital Path of my current setup:
Control PC > Patch Cable > Router > Wifi > Audio PC > DAC

My plan is to improve the patch cable used and to move from wifi to cable for the connection between the router and the audio PC.

 

[Nikhil]

Nikhil, in a previous post you apparently admitted you understand TCP/IP "works". So a bit surprised to see this demand of "reference". Anyway, you can always look up IETF site for all things Internet. If you do need reference line-wise and interpretation wise, then you will either have to wait till I can find enough spare time to highlight specific parts from the protocol's official specification for your reference or you'll have to hire me. I can assure you if hired, I'll do it pretty quickly Alternatively, there is this thing called Google. I am sure you would rather type in Google TCP/IP specification. The pages it throws up will answer many more questions than this alone.

Why should I use Google when there are such phenomenal resources on here?

I do understand TCP/IP. That is why I wanted to know where in the protocol is it specifically stated that TCP/IP can account for cross talk and noise.

 

[Thad E Ginathom]

I am running wifi at the moment. I have been recommended to use cable.
I was told that there is an improvement in the sound over using wifi.

Think of networking like the post service: the men, the route, the vehicles, can all change, but the contents of the letter does not. This is the "black box" that I spoke of early. Sorry for another analogy, hope you will accept it as food for thought, if nothing else.

If there is a real, objective, difference in sound, then something else is happening. It simply can't be a result of the network physical transport. Can wifi signal radiation itself be a source of noise to hifi equipment? Even if it can, I imagine we'd never be able to live without someone else's (along with all the other unwanted radio crap in the air around us) even if we didn't use it ourselves.

However, a few people who used cable had issues with noise creeping into the system from secondary sources.

I'm thinking...

1. CAT-n ethernet devices contain electrical isolators. Not sure about this. Ranjeet?

2. The data is either correct, and accepted, or not, and rejected. This, as I think you said, is trivial, and there is no room for noise.

I guess its a matter of picking your poison.

Possibly literally! Some suggest that all this radio interference is bad for us, let alone hifi. I used to think this too. It's not that I changed my mind, just that I gave up worrying about something I can't hide from

My plan is to improve the patch cable used and to move from wifi to cable for the connection between the router and the audio PC.

My favourite cable company (No prizes for guessing!). They will sell you a tested and certified fly lead. hyeah:

They deliver promptly to India, and their courier charges are very reasonable.

~

 

[Nikhil]

Think of networking like the post service: the men, the route, the vehicles, can all change, but the contents of the letter does not. This is the "black box" that I spoke of early. Sorry for another analogy, hope you will accept it as food for thought, if nothing else.
...
~

Thad the analogy again refers to the logical layer of the network construct.
I think this is where you and Ranjeet maintain that the network protocol is capable of handling the data transfer perfectly.

My suspicion is that down at the physical layer i.e. the wire, down to the differential signaling etc. there is the assumption is that the construction of the cable is perfect. I have a suspicion that things aren't all well here specially in generic cable. Flaws in the terminations or cable construction can introduce noise. For computer data applications this may not be an issue - it may affect network latency.

My thinking is that a well made cable adhering to the Cat 6/7 spec should by design be made to a higher standard. Getting it properly punched down and terminated by a qualified vendor should help improve things.

 

[Thad E Ginathom]

No, Nikhil... The point of the levels model is that each level it looks as if you are looking across the valley to the same level on the other side (sorry, I think in pictures for my own understanding). At the application level, application talks to application. Nothing else matters. It is not only an assumption that everything below it works, it is a given: it has to work, or the whole idea falls to pieces.

there is the assumption is that the construction of the cable is perfect.

No, there is no such assumption. Quite the opposite: that is why the error correction is built in, and why the facility is there to reject erroneous data, and it will be rejected. The system will either work or fail. What I mean here by "failure" would be complete failure to connect usefully at all, or not achieving sufficient speed to play our audio without dropouts.

I have a suspicion that things aren't all well here specially in generic cable.

It's taken care of. But also you are right! See the Blue Jeans article: much of the networking cable we buy is not up to spec and, anyone can make anything and print "CAT-5" on the outside. It's scandalous!

My thinking is that a well made cable adhering to the Cat 6/7 spec should by design be made to a higher standard.

My thinking (despite the IT work background), until I read that BJ article just a few weeks ago was that it was. But it isn't. So, by all means buy genuine Belden (or equiv) cable, and get it installed properly. Here we have no difference of thinking. Buy BJ certified flyleads. I don't see why we should not take as much care with our home installation as we would at work.

Flaws in the terminations or cable construction can introduce noise.

Flaws in the cable or terminations could cause packets to be lost. I don't think the noise is quite the same as the noise we might get if we run an analogue cable along a high-power electricity cable. I don't think there is a digital equivalent to "mains hum." But it can certainly interfere. It won't alter the data as the error correction will work, but it could slow things down. There's still an awful lot of safety margin built in.

Hmmm... There's still an awful lot of safety margin built in, as long as it installed and used to spec. That does not include running it on top of mains cables.

How big is you conduit?

 

[Thad E Ginathom]

A Couple of Weeks Later...

Wondering how you got on, Nikhil?

Anyway, you know how browsing is, and I was on Belden's site just now, and noticed a section of articles on harsh environments. You might find it interesting, even if it is only to drool over the extent to which one can over-engineer. I enjoy such a drool


Belden: Articles on Harsh Environments


~

 

[Thad E Ginathom]

Also discovered while browsing... CAT-8 is on the way!

 

[Nikhil]

Update:

Was a little busy these last couple of weeks with travel.
After considering different suppliers finally ordered online from VPI USA

1. 100 ft of Flat Stranded Shielded Cable
2. Patch cable: 3 pcs of CAT7 Stranded Shielded Cable 2 ft length

Total cost including shipping to HYD approx $100/-
Items were shipped via USPS Global Priority Mail.

Will be interesting to see if this makes any difference to my setup.

 

[Nikhil]

My cable package finally landed on Indian shores after a long journey. USPS packages are handled by India Post so was informed by my postman. Unfortunately I had some travelling to do so had to wait until I got back this week to go over to my neighborhood post office and pick up the package.

Indians Customs lobbed on Rs 1,729 customs duty so add that to the total cost. ($100 = Rs 6,250/-)
The package also had taken quite a beating at the hands of the Indian Postal Service.

Fortunately VPI had double wrapped and packed the cables with padding.
I have to say I am very happy with the care taken by VPI. They even threw in a sample 6" Cat 6 patch cable. Thank you very much VPI.

And finally I have my hands on CAT 7 cable!! The cable is a flat design that can be placed under carpet if needed. I plan to just skirt the cable along the walls of my living room for now. The cable jacket is plenty sturdy to take on being fish wired thru any ducting if needed.

I have to say the cable is doing well in my setup right now. Sound is great but I just want to let the cable settle in. Will do a proper listening over the next couple of days before posting impressions. I had some 3 Doors (The Greatest Hits) playing earlier this evening and now have switched to some Buddha Bar Down tempo electronic Lounge music. I like what I am listening to so far!

Given that this is not much outlay - highly recommended +++

 

[Nikhil]

Listening Impressions so far indicate that there is a "softer" sound with the Cat 7 cable in place.
This is pretty noticeable at times giving the sound a little better presence.

Changes Made to my setup:

1. Have changed the patch cable from the Router to my Control PC with Cat 7 cable.
2. Audio PC is now connected to the router with the Cat 7 cable (earlier it was wifi)

Once again I think the shielding does a better job of keeping the HF "dirt" out.
Earlier with the wifi there is a sort of HF hash in the sound which is now cleaned up.

Very happy with the results so far. Have turned off the wifi on the Audio PC.
Letting it run over cable now and will soon have the cable placed in the room.

 

[keith_correa]

Earlier with the wifi there is a sort of HF hash in the sound which is now cleaned up.

What does HF hash sound like? And, please don't tell me it sounds like - "hash"

 

[Nikhil]

What does HF hash sound like? And, please don't tell me it sounds like - "hash"

I tried to explain it earlier but I guess it's a challenge for the skeptics.

I think what best explains it is that its an improvement in the signal to noise ratio.
With a reduction in noise a better cleaner signal comes through.
In my setup it comes through as a softer and cleaner sound.

 

[sidvee]

With a reduction in noise a better cleaner signal comes through.
In my setup it comes through as a softer and cleaner sound.

And in the end that is what matters, that the listener can hear an improvement.
Cheers,
Sid

 

[nandac]

This thread is like 6 years old! But just wanted to check the availability of CAT7 cables in India now.