Jump to content

Hybrid Cable. Mains + 4 Data + 8 Audio: Join the 3K Club?


Mark Payne

Recommended Posts

The Digital Multicore Dream vs Practical Reality

 

Why do we like the idea of a remote stage box linked back to the FOH console on a digital link?

One of the first mantra chants you will hear is about "small light multicores". Its Just one or two CAt5 lines and off you go. Yeh right….

 

The reality is different. We still have a habit of running mains from stage to FOH to ensure a consistent earth path, not to mention a supply we can trust.

Then think about some extra traditional twisted pair lines for show comms, FOH to monitor shout lines, system control (eg d&b CAN Bus) and maybe we even let the lighting boys steal a line for DMX. Then add in some more Cat5 for the PC network we seem to now need to make everywhere we go and….

 

… You now have a bunch of cables, 100M long, taped together which you will "figure of 8" into a trunk again. How is this smaller?

 

The answer is that it is not smaller. Unless you are doing pub gigs it is likely that you are going to need flexible facility. Facility wins over size every time even if you are piling gear out of the back of a LWB transit.

 

So Tell Me Again… Why is a "Digital Snake" a Good Idea?

 

… Well it is a different idea. We have to go with it because its what the stuff is doing! At SFL our digital connect console products are currently:

 

Digidesign Venue Stage Rack Systems: 4 lines of coaxial cable on BNC… 2 main, 2 redundant

Yamaha M7CL ES: 2 lines of CAT5 EtherSound ES100, In Ring topology, effectively 1 main and 1 redundant

Roland M400 and M48 personal monitors: REAC protocol on CAT5 lines. Either one line or main and standby lines.

Aviom personal monitors: A-Net over CAT5. Single line.

 

So the Digi console (Coax BNC) and the rest of the stuff (CAT5) don’t even share the same cable media solution! Lets not kid ourselves that a digital standard will ever emerge that all provides will use. It ain't gonna happen.

 

• What we like about the remote stage box is that A/D conversion happens as close to the mic as possible. Noise rejection is better as the analogue path is shorter.

• In a world where we like to do output returns in AES/EBU digital to cut down back end conversion DA AD stages we like AES appearing at the stage end. AES/EBU on balanced line turns into a pile of poo much beyond 100M so we eliminate a run down the multicore at least.

• For install solutions the option of having the FOH console in differing locations is a least possible at reasonable cost.

An Invite to the "3K Club"

 

Unless someone wants to advise us otherwise, no one is making the cable we want.

 

We are currently working with a well known reputable cable manufacturer on a custom hybrid design and I have the spec on my desk as a PDF.

If you call me at the office and have a chat I will email you the spec, I may also be convinced to share target price info with you but that will take a call! . You can also email me mark@sflgroup.co.uk for the spec.

 

We will not be selling this cable, it will come direct. We just need to see if there is enough interest out there to get the minimum run of 3 Km made (we don’t want 3Km of this stuff on our own!).

 

Basically it’s a single cable:

 

• Outer Dia = 26.1mm

• 1 Mains = 2.5mm 3 core in its own additional sheath "down the middle"

• 4 lines of CAt5 Data on solid core (all the best transmission solutions are solid) AWG 24 (better than AWG 26). F/UTP. Pre jacketed.

• 8 Lines of 110 Ohm spec "digital capable" twisted pair pre jacketed.

 

So there you have it

16A Mains + 4 Data + 8 Audio (or anything else you can do with shielded twisted pair).

 

Anyone have a better idea?

Want to join the SFL 3K club?

 

Mark

0118 969 0900

mark@sflgroup.co.uk

Link to comment
Share on other sites

  • Replies 41
  • Created
  • Last Reply

Hi Mark

Given the use of solid core CAT5 cable, how do you rate the probable long term reliability of this cable? Is the thinking along the lines of "given all the other cables in the jacket, particularly the 2.5mm2 mains, it shouldn't ever get kinked tight enough to cause a problem"?

 

Cheers

David

Link to comment
Share on other sites

Yup id echo that

 

solid core CAt5 is great aslong as you dont flex it otherwise its good night vienna-

obviously if its in with this lot you prob wont be able to kink it/bend it that much, but id be cautious, I have about 5 solid core CAT5 cables here that have broken cores in places other than the ends (id expect that at least)

 

Im led to believe that normal cat5 is fine, though I normally buy the heavy duty stuff from CPC, has a nice thick PVC jacket, is quite heavy but seems very tough, its also quite reasonably priced.

 

 

Dan

Link to comment
Share on other sites

David.

 

The simple answer is that you cannot kink a 26mm OD cable ;-)

 

Other answers include that we are already using Solid Core CAT5 in all of our touring systems (GepCo cable for example). Even unprotected by the other cables around them without problems. Obviously I am not talking about the grey crap that comes out of a 300M cardboard box. That will not tour. However you should know that the grey crap is actually pretty good performance wise, just not very durable.

 

The issue is that if you "think" a stranded cable is better for some reason... it is not. We live in a 100M world.

 

Check out

 

http://www.ethersound.com/technology/compa...ty.php?o=cables

 

Then see something in common about all CAT5 cables that gets us over 100M in an ES world.

We also know this is true with Roland REAC

 

SOLID AWG24 is the only way to go.

 

Cheers

 

Mark

 

 

 

 

Hi Mark

Given the use of solid core CAT5 cable, how do you rate the probable long term reliability of this cable? Is the thinking along the lines of "given all the other cables in the jacket, particularly the 2.5mm2 mains, it shouldn't ever get kinked tight enough to cause a problem"?

 

Cheers

David

 

 

A concurrent post has been automatically merged from this point on.

 

Hi Dan

 

"solid core CAt5 is great aslong as you dont flex it otherwise its good night vienna- "

 

Dan, this is not our experience.

 

Please could you consider the ES specs and certified cable list that I have shown you in the post above (Link).

 

As you use and buy CAT5. I would be interested in what you use it for and how long it is?

 

I am talking about show critical, high end, full utilisation of 64 channel bidirectional ES at 100M+ length.

I have to Know that I know that I know this will work 100% as my whole audio solution is going to be based on it.

 

We should all remember that at the limits digital does not degrade, it just stops working .......

 

Cheers

 

M

 

 

Yup id echo that

 

solid core CAt5 is great aslong as you dont flex it otherwise its good night vienna-

obviously if its in with this lot you prob wont be able to kink it/bend it that much, but id be cautious, I have about 5 solid core CAT5 cables here that have broken cores in places other than the ends (id expect that at least)

 

Im led to believe that normal cat5 is fine, though I normally buy the heavy duty stuff from CPC, has a nice thick PVC jacket, is quite heavy but seems very tough, its also quite reasonably priced.

 

 

Dan

 

 

A concurrent post has been automatically merged from this point on.

 

Just to be sure this is understood. Our Cable partner here is Klotz.

 

I have the following feedback (just in) on my questions about ES spec and comparisons to Klotz's other "best in class" (for ES) Cat5 Cables

 

The CAT5 cable within this hyprid cable is designed to be a standard CAT5e AWG24 cable with solid conductors,

but without an overall braided shield, as we have it on the Klotz RC5SBSW cable (the best EtherSound rated cable).

The reason for this is simply a cost factor reason, as an overall braided shield would make the cable much more expensive.

 

As far as the transmission length in EtherSound applications is concerned, we expect it to be as far as the RC5SBSW cable.

The main criteria is the AWG24 solid conductor construction to assure these transmission distances.

 

 

Its not just about doing it. We have to do it right.

 

Look it up for yourself but RC5SBSW is certified for 120M by EtherSound

 

M

Link to comment
Share on other sites

Hi Mark

 

Not having a go, not at all, if I was buying 3000m of cable id want to be 101% sure it was going to do what I want it to do, and safely.

If your outer core size in the region of 26mm I think youd be hard pushed to bend that suitably enough to damage any of the cable inside (and I speak mearly from working at a well known cable manufacturer years ago)

 

Ive used some solid core with both soundweb, and ethersound. Admittadly, the CAT was just a couple or runs not in a loom or anything, which does seriously increase the chances of damage by outside elements, something hopefully you will not endure (and quite possibly why our CAT5 solid cores failed- cant be watching everything all the time)

 

Id be interested in what the manufacturer comes up with in terms of cable placement within the sheath.

Id be guessing here, but they will prob lay the mains down the middle with the smaller cables around it, keeps the overall sheath flexible, be sure that they dont spec 2mm of pvc all around the cables, as in reality this doesn't offer anything other than holding it all together, id be looking at 5mm same as you get on H07.

 

If you have any doubt, id want to make up a say 10 meter loom of the said cables, tightly tape them all together all along the loom, then test it to destruction, esp bending it, flexing it, even at the sharpest angles.

Then try wheeling dollies over it, dropping flight cases on it, sitting wedges on it, you need to be sure of the mechanical elements as much as the electrical elements.

Temperature also is worth testing. Ie you run the loom outside in festival mode and its left out there for 3 days in all weathers/elements.

 

I'm sure all this is being considered, just making points.

 

interestingly I had a convo with a sparks, over CAT5 usage-HE says it generally isnt rated for mains isolation anything over 90V which does pose a question that it shouldnt be run along with mains power of course assuming that the mains in the "loom" is individually sheathed, (wrapping all three cores) as well as the CAT5 being the same it wouldnt be a problem, though thats going to be more than 25mm over all size I would think, along with the 8 pairs.

So that pretty much condems every office installation that runs there cat5 in trunking along with the mains for power points.

 

Dan

Link to comment
Share on other sites

I was told a little while ago NEVER to run Mains and Data cables together? Not only because the mains could do funny things to the data, but also, if you cut a cable expecting it to be a data cable, and there's mains going down it, things could become a little shocking...
Link to comment
Share on other sites

Dan you are not having a go!

 

We are now having robust debate between grown-ups!

Forgive me if I challenge you as you challenge me!

Actually that is the point of my post. Truth comes from argument.

 

I hear you. Email me mark@sflgroup.co.uk and I will return the spec of the cable with PDF and images as I cannot post that here.

 

BTW ... we are not buying 3000M! We are finding people that want to buy a quantity together. We think we are developing a solution to a problem here..... rather than a solution where there is no problem!

 

M

 

Hi Mark

 

Not having a go, not at all, if I was buying 3000m of cable id want to be 101% sure it was going to do what I want it to do, and safely.

If your outer core size in the region of 26mm I think youd be hard pushed to bend that suitably enough to damage any of the cable inside (and I speak mearly from working at a well known cable manufacturer years ago)

 

Ive used some solid core with both soundweb, and ethersound. Admittadly, the CAT was just a couple or runs not in a loom or anything, which does seriously increase the chances of damage by outside elements, something hopefully you will not endure (and quite possibly why our CAT5 solid cores failed- cant be watching everything all the time)

 

Id be interested in what the manufacturer comes up with in terms of cable placement within the sheath.

Id be guessing here, but they will prob lay the mains down the middle with the smaller cables around it, keeps the overall sheath flexible, be sure that they dont spec 2mm of pvc all around the cables, as in reality this doesn't offer anything other than holding it all together, id be looking at 5mm same as you get on H07.

 

If you have any doubt, id want to make up a say 10 meter loom of the said cables, tightly tape them all together all along the loom, then test it to destruction, esp bending it, flexing it, even at the sharpest angles.

Then try wheeling dollies over it, dropping flight cases on it, sitting wedges on it, you need to be sure of the mechanical elements as much as the electrical elements.

Temperature also is worth testing. Ie you run the loom outside in festival mode and its left out there for 3 days in all weathers/elements.

 

I'm sure all this is being considered, just making points.

 

interestingly I had a convo with a sparks, over CAT5 usage-HE says it generally isnt rated for mains isolation anything over 90V which does pose a question that it shouldnt be run along with mains power of course assuming that the mains in the "loom" is individually sheathed, (wrapping all three cores) as well as the CAT5 being the same it wouldnt be a problem, though thats going to be more than 25mm over all size I would think, along with the 8 pairs.

So that pretty much condems every office installation that runs there cat5 in trunking along with the mains for power points.

 

Dan

 

 

A concurrent post has been automatically merged from this point on.

 

And there inlies another debate ....

 

We already strap a 32A mains run to the multi. How do we define proximity? We already run them together.

 

The issue of interfearence is interesting. How does 50Hz mains induce itself onto 48KHz clocked digital signal? What does that sound like?

The return core useage however may be analogue. Is it line level or mic (probably line)? How much gain to we need to apply to hear it?

Ask yourself what you hear from induced mains noise on a mic line. Where does it come from and what harmonics do you hear?

 

I ask some retorical questions here. We have already answered some of them by experience. This is why we would consider doing such a thing.

 

If you cut this cable onsite with your knife... the last shock you will get will be from the mains in the middle. I would have beaten you to death from behind with a stage weight far earlier ;-)

 

The legaility of running HV and LV in the same cable. Interesting, I need to specically ask...... German cable manufacturer who alreay makes such cables (not quite what we need). Trust me its been asked before and answered. Let me get a statement from them.

 

Keep em comming.

What are the real issues?

Which are sacred cows?

Which are predjudice?

 

M

 

I was told a little while ago NEVER to run Mains and Data cables together? Not only because the mains could do funny things to the data, but also, if you cut a cable expecting it to be a data cable, and there's mains going down it, things could become a little shocking...
Link to comment
Share on other sites

Ah with regard to the strapping of a 32 mains to your multi.

Im hoping that the 32 is 3 core TRS H07 or something therefore its inner cores are covered in PVC as is all 3 with a rubber sheath, and therefore adequately protected.

However in this "super loom" im assuming it wont have the same level of isolation (no outer sheath wrapping the 3 cores) so what im suggesting is if the isolation is compromised on the live mains feed, the isolation of the cat5 feed isnt adequate enough to prevent mains getting into the CAT5 meaning possibly buy buy expensive digital card, maybe even board.

and the same goes for the isolation of the Coax and tie lines.

 

Dan

Link to comment
Share on other sites

Hi Mark

 

Are you planning a different solution for your Digidesign stuff or just sticking with a coax multi and mains triped together? Could you loose a few AES lines (do you really need 8?) and add some coax to create a "one cable fits all" solution.

 

Personally, I love hybrid cables and think in many situations they are a perfect solution, but I think having this many eggs in one basket would make me slightly nervous, given the potential cost of the cable. Being able to remove failed components of a multi is very useful, even if the likely hood of failure is greater due to less overall mechanical protection.

Link to comment
Share on other sites

I was told a little while ago NEVER to run Mains and Data cables together? Not only because the mains could do funny things to the data, but also, if you cut a cable expecting it to be a data cable, and there's mains going down it, things could become a little shocking...

 

Simple answer here, don't ever cut any cable without confirming exactly what it is, and whether it's live or not.

 

interestingly I had a convo with a sparks, over CAT5 usage-HE says it generally isnt rated for mains isolation anything over 90V which does pose a question that it shouldnt be run along with mains power of course assuming that the mains in the "loom" is individually sheathed, (wrapping all three cores) as well as the CAT5 being the same it wouldnt be a problem, though thats going to be more than 25mm over all size I would think, along with the 8 pairs.

So that pretty much condems every office installation that runs there cat5 in trunking along with the mains for power points.

 

That's certainly true where double insulation isn't provided, ie: using conduit cables in conduit or trunking. This is why in the office installs you reference you should always see the use of split trunking with seperate mains and data sections.

 

Where double insulation is provided, say, on the IEC cable between the wall and your PC, it's perfectly happy sitting right next to a mix of data cables.

 

It's been made clear that double insulation is provided in this cable:

 

• 1 Mains = 2.5mm 3 core in its own additional sheath "down the middle"
Link to comment
Share on other sites

Hi Dan

 

I have sent you the spec. All the cores are individually Jacketed.... including the mains. This also makes it nice to deal with when we break it out at the other end. Hope this helps

 

Mark

 

Ah with regard to the strapping of a 32 mains to your multi.

Im hoping that the 32 is 3 core TRS H07 or something therefore its inner cores are covered in PVC as is all 3 with a rubber sheath, and therefore adequately protected.

However in this "super loom" im assuming it wont have the same level of isolation (no outer sheath wrapping the 3 cores) so what im suggesting is if the isolation is compromised on the live mains feed, the isolation of the cat5 feed isnt adequate enough to prevent mains getting into the CAT5 meaning possibly buy buy expensive digital card, maybe even board.

and the same goes for the isolation of the Coax and tie lines.

 

Dan

Link to comment
Share on other sites

Hi Chappie

 

Arh well the moment we put robust coax down this as well it gets er.... huge.

I guess the plan here would be to run this new thing AND the 4 way coax systems we already have for the Digi Venue systems.

 

We really want 8 lines of traditional stuff for all the other adhoc ties we do. If we specify another custom hybrid then we need another 3Km!

 

How much do you want ;-)

 

Love

 

M

 

Hi Mark

 

Are you planning a different solution for your Digidesign stuff or just sticking with a coax multi and mains triped together? Could you loose a few AES lines (do you really need 8?) and add some coax to create a "one cable fits all" solution.

 

Personally, I love hybrid cables and think in many situations they are a perfect solution, but I think having this many eggs in one basket would make me slightly nervous, given the potential cost of the cable. Being able to remove failed components of a multi is very useful, even if the likely hood of failure is greater due to less overall mechanical protection.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.