ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Console Connectivity Solutions => Topic started by: James Hampshire-Perks on September 13, 2020, 03:49:41 AM

Title: Cat6a shielding connected via wall plates
Post by: James Hampshire-Perks on September 13, 2020, 03:49:41 AM
Hi All,

I'm installing some cat6a lines in our venue, to be used for audio console (M32) to stage box (DL32) and any other application that requires network lines from FOH to stage.

I have thought of a potential issue with my current setup and am just seeking some advise as to whether or not problems my arise.

I have 2 cat6a lines both terminating at neutrik cta6a feedthrough connectors, these are mounted on a steel wall plate (plug box cover) both ends. Being steel this connects the shields of the two cable runs via the housing of the connectors.

So if one line was being used for FOH audio to stage box and another for lighting or a video application, their shields would be connected. This sounds like a bad thing in my brain.

Any thoughts appreciated.
Title: Posting Rules
Post by: Mac Kerr on September 13, 2020, 06:29:35 AM
Hi All,

I'm installing some cat6a lines in our venue, to be used for audio console (M32) to stage box (DL32) and any other application that requires network lines from FOH to stage.

I have thought of a potential issue with my current setup and am just seeking some advise as to whether or not problems my arise.

I have 2 cat6a lines both terminating at neutrik cta6a feedthrough connectors, these are mounted on a steel wall plate (plug box cover) both ends. Being steel this connects the shields of the two cable runs via the housing of the connectors.

So if one line was being used for FOH audio to stage box and another for lighting or a video application, their shields would be connected. This sounds like a bad thing in my brain.

Any thoughts appreciated.

Please go to your profile and change your name to your real full name as required by the posting rules.

Mac
Admin
Title: Re: Cat6a shielding connected via wall plates
Post by: Erik Jerde on September 20, 2020, 08:17:59 PM
Hi All,

I'm installing some cat6a lines in our venue, to be used for audio console (M32) to stage box (DL32) and any other application that requires network lines from FOH to stage.

I have thought of a potential issue with my current setup and am just seeking some advise as to whether or not problems my arise.

I have 2 cat6a lines both terminating at neutrik cta6a feedthrough connectors, these are mounted on a steel wall plate (plug box cover) both ends. Being steel this connects the shields of the two cable runs via the housing of the connectors.

So if one line was being used for FOH audio to stage box and another for lighting or a video application, their shields would be connected. This sounds like a bad thing in my brain.

Any thoughts appreciated.

I can’t be sure without an exact part number but it looks like the cat6a products don’t have the ability to defeat the panel ground connection like the D series ethercon products do.  That’s a bummer.

Given the x/m32 ground issues and how it’s becoming more common to use shielded catx for analog snakes I’d have some concerns about common ground across systems as well.

If you’re committed to the cat6a rated connectors you could try a wrap of etape along with one of the colored plastic rings and effect a DIY isolation.

If you’re not committed to those connectors just swap for the ones with selectable panel ground bond.  If you’ve got a proper cable qualifier you could even test to see what sort of actual impact it has.  It would be interesting to see the effect of the lower rated connectors in real world use vs the cat6a.
Title: Re: Cat6a shielding connected via wall plates
Post by: Russell Ault on September 21, 2020, 12:24:00 AM
If audio power uses an isolated ground in your building and other departments don't I could see the potential for ground loops if audio is using one network line and, say, lighting is using the other (since you'd basically be tying your isolated ground to the building's ground through the shields of those two Ethernet cables).

If everyone is using the same power ground then I'm not sure I see why there'd be a problem? IIRC, the AES50 shielding weirdness with the X32 platform is all about using the shell on the EtherCON connector to make sure that all the parts of the EtherCON that should be tied to ground actually are. My sense is that adding a few extra grounding points on the cable's shield shouldn't cause any (additional) problems (as long as this doesn't cause ground loops, anyway).

-Russ
Title: Re: Cat6a shielding connected via wall plates
Post by: Chrysander 'C.R.' Young on September 22, 2020, 08:45:09 AM
Hi All,

I'm installing some cat6a lines in our venue, to be used for audio console (M32) to stage box (DL32) and any other application that requires network lines from FOH to stage.

I have thought of a potential issue with my current setup and am just seeking some advise as to whether or not problems my arise.

I have 2 cat6a lines both terminating at neutrik cta6a feedthrough connectors, these are mounted on a steel wall plate (plug box cover) both ends. Being steel this connects the shields of the two cable runs via the housing of the connectors.

So if one line was being used for FOH audio to stage box and another for lighting or a video application, their shields would be connected. This sounds like a bad thing in my brain.

Any thoughts appreciated.

Why Cat6a?  That stuff is heavier, thicker, more expensive, and harder to work with than other options and is way overkill for your needs.  For M32/X32, Cat5e with Ethercon is the right answer. 
Title: Re: Cat6a shielding connected via wall plates
Post by: Rob Spence on September 22, 2020, 10:01:54 AM
Why Cat6a?  That stuff is heavier, thicker, more expensive, and harder to work with than other options and is way overkill for your needs.  For M32/X32, Cat5e with Ethercon is the right answer.

Well, for installs where the wires may be in place for decades, it makes sense to use a more current cable. After all, the M32 et al may not be the console in use even just a few years from now.

My $0.02
Title: Re: Cat6a shielding connected via wall plates
Post by: John L Nobile on September 22, 2020, 10:46:47 AM
Well, for installs where the wires may be in place for decades, it makes sense to use a more current cable. After all, the M32 et al may not be the console in use even just a few years from now.

My $0.02

We're now up to Cat 8 cable and it's supposedly backward compatible. Looks like it's meant to compete with short fiber runs.

https://www.cablesandkits.com/learning-center/what-are-cat8-ethernet-cables

Title: Re: Cat6a shielding connected via wall plates
Post by: Brian Jojade on September 22, 2020, 12:26:52 PM
We're now up to Cat 8 cable and it's supposedly backward compatible. Looks like it's meant to compete with short fiber runs.

https://www.cablesandkits.com/learning-center/what-are-cat8-ethernet-cables

Cat 8 has a max cable length of 30 meters (about 100 feet). Great for server rooms and such, but not as a full installation technology.

Cat 6 is rated for 10 gigabit speeds for up to about 150 feet of cable, whereas cat6a is rated to do 10 gig for the full 100 meters.

In the overall scheme of things, cat 6 cable should be adequate for most things for the next decade or so.  However, we are starting to see more and more devices that support 10 gig ethernet.  If the cost allows installing cat 6a wiring, you can enjoy a few more years out of the installation before it will need replacement.  Replacing working cable to get something a little faster down the road is a much harder item to get into the budget.

Now, on an interesting note, I was working on a piece of equipment in a doctors office yesterday.  I came across a warning in the instructions that was interesting to me.  It specifically, and in BOLD letters said Do NOT use shielded cat cable for connecting the device, as that would present a risk of electrical shock to the patient.  Very weird to see that in the instructions.  I'm wondering what scenario could cause that to happen.

Title: Re: Cat6a shielding connected via wall plates
Post by: Russell Ault on September 22, 2020, 01:27:24 PM
[...]
Now, on an interesting note, I was working on a piece of equipment in a doctors office yesterday.  I came across a warning in the instructions that was interesting to me.  It specifically, and in BOLD letters said Do NOT use shielded cat cable for connecting the device, as that would present a risk of electrical shock to the patient.  Very weird to see that in the instructions.  I'm wondering what scenario could cause that to happen.

Defibrillation?

-Russ
Title: Re: Cat6a shielding connected via wall plates
Post by: Erik Jerde on September 25, 2020, 09:41:33 PM
Cat 8 has a max cable length of 30 meters (about 100 feet). Great for server rooms and such, but not as a full installation technology.

Cat 6 is rated for 10 gigabit speeds for up to about 150 feet of cable, whereas cat6a is rated to do 10 gig for the full 100 meters.

In the overall scheme of things, cat 6 cable should be adequate for most things for the next decade or so.  However, we are starting to see more and more devices that support 10 gig ethernet.  If the cost allows installing cat 6a wiring, you can enjoy a few more years out of the installation before it will need replacement.  Replacing working cable to get something a little faster down the road is a much harder item to get into the budget.

Now, on an interesting note, I was working on a piece of equipment in a doctors office yesterday.  I came across a warning in the instructions that was interesting to me.  It specifically, and in BOLD letters said Do NOT use shielded cat cable for connecting the device, as that would present a risk of electrical shock to the patient.  Very weird to see that in the instructions.  I'm wondering what scenario could cause that to happen.

In the AV world the big reason for higher spec cable is video transmission.  HDBT solutions from reputable mfgrs will have transmission distance listed by resolution on specific cable types.