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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB: The Classic Live Audio Board => Topic started by: Andrea Litti on December 24, 2018, 04:19:28 am

Title: Long distance cable runs and mixing different cat-x cables
Post by: Andrea Litti on December 24, 2018, 04:19:28 am
Hello,

I was asked to provide a temporary install for a videomapping performance where the speakers have to be placed some 100 meters away from the audio source. I have a Qu16 mixer with Ar 2412 stage box and three separate cat cables of 25 to 40 meters each. Two of them are cat5 and one is cat6. A&H says dsnake works for up to 120 meters of cable run. Would there be issues in mixing different categories (in doing this I would use neutrik joints)? Should I use one single 100m cable? Thanks
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Erik Jerde on December 24, 2018, 10:19:41 am
Hello,

I was asked to provide a temporary install for a videomapping performance where the speakers have to be placed some 100 meters away from the audio source. I have a Qu16 mixer with Ar 2412 stage box and three separate cat cables of 25 to 40 meters each. Two of them are cat5 and one is cat6. A&H says dsnake works for up to 120 meters of cable run. Would there be issues in mixing different categories (in doing this I would use neutrik joints)? Should I use one single 100m cable? Thanks

The cable type won't matter as long as all the cables meet the mfgr specs for digital snake interconnect.  Similarily check the mfgr docs for their word on junctions in the cable.  I know some mfgrs (like DiGiCo) specifically state a single unbroken cable run between console and stage box for catx connections.  Even if that is the case it may still work.  Personally I'd rather have a single unbroken run.  Connections are common failure points and the fewer of those the better, especially in a snake run that can take out your entire show.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: brian maddox on December 24, 2018, 11:43:28 am
Hello,

I was asked to provide a temporary install for a videomapping performance where the speakers have to be placed some 100 meters away from the audio source. I have a Qu16 mixer with Ar 2412 stage box and three separate cat cables of 25 to 40 meters each. Two of them are cat5 and one is cat6. A&H says dsnake works for up to 120 meters of cable run. Would there be issues in mixing different categories (in doing this I would use neutrik joints)? Should I use one single 100m cable? Thanks

This would give me the Willies.  That doesn't mean it categorically won't work.  In fact, i suspect it will do something far worse.  It will probably work, but just barely.  Which then means that it will pick the worst possible time to fail when someone happens to look at the cable funny while they walk by [or step on it or bump it slightly or whatever], right in the middle of the show.

If you can source and deploy a single, unbroken run of cable, i would do so.  Even if just for your own piece of mind.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Keith Broughton on December 24, 2018, 12:04:26 pm
Hello,

I was asked to provide a temporary install for a videomapping performance where the speakers have to be placed some 100 meters away from the audio source. I have a Qu16 mixer with Ar 2412 stage box and three separate cat cables of 25 to 40 meters each. Two of them are cat5 and one is cat6. A&H says dsnake works for up to 120 meters of cable run. Would there be issues in mixing different categories (in doing this I would use neutrik joints)? Should I use one single 100m cable? Thanks
I have actually tried to run this configuration with regular, over the counter,  CAT 5 cable and could not get reliable results over 100'!
CAT 5E has worked for me up to 200'.
From my experience with this exact same setup, I suggest that you use CAT6 for 300' run, and avoid connections on the way, if you want reliable results.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Brian Jojade on December 24, 2018, 02:33:07 pm
Should I use one single 100m cable?

If a single cable is an option, that is by far preferred than a connection with breaks in it.  Couplers have the potential to degrade your signal and cause problems, even if you're well below the maximum cable length.  The reason for a limited maximum cable length is due to timing issues, not signal strength.

Are you sure you have Cat 5 cable, and not cat5e?  Cat 5 is an obsolete spec that is unlikely to be easily found anywhere. Cat5e cable costs pretty much the same.  Nobody that I'm aware of is still producing cat 5 cable.  For short cable runs, you might be able to get away with cat5 when cat5e is the minimum spec, but as the cable gets longer, the more you need to adhere to the specs.

The cost difference to go from cat5e to cat6 is pretty minimal, so I'd recommend going cat6 if possible, without any couplers.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Scott Mullane on December 24, 2018, 04:58:44 pm
I run A&H digital mixing consoles and the max length does tend to vary depending on the cable. Eurocable vs. Belden vs. Canare etc. They are all within about 10% though.

I definitely would avoid linking cables and the general rule is that each connection adds about 10m to the virtual cable length. Although this is not entirely true, it is a good yard stick. However, connection failure for a critical connection would terrify me. Use one single unbroken cable.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Karel Noon on December 24, 2018, 06:33:56 pm
Want to be safe?

Take Format converters and optical cables!
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Mike Caldwell on December 24, 2018, 08:38:47 pm
What do you have to run the cable through, around and over to get from the mixer to the stage box?

How many channels of audio are we talking about?
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Andrea Litti on December 24, 2018, 09:44:07 pm
Thanks for all the replies. I have only a stereo audio channel coming from the video guys. The audience is confined in a listening area on a terrace and will have no physical interaction with the cable, which runs inside cable ramps over a grassy field. My cables are two cat5 with neutrik connectors (25 and 30 meters long both bought in 2014) and a 30 meters cat6 purchased recently. I've already used the two cat5 cables joint together with a neutrik adapter with my Gld for 16 channels with no issues. I've never used all three together so far. I'd rather not buy nor rent a new 100m cable for a single gig, and was thinking about the possibility of doing 60 meters with cat cables and the other 30 with xlr's from the stage box to the speakers (three RCF Art710 for 60 people in attendance at moderate level)
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: brian maddox on December 24, 2018, 10:12:03 pm
Thanks for all the replies. I have only a stereo audio channel coming from the video guys. The audience is confined in a listening area on a terrace and will have no physical interaction with the cable, which runs inside cable ramps over a grassy field. My cables are two cat5 with neutrik connectors (25 and 30 meters long both bought in 2014) and a 30 meters cat6 purchased recently. I've already used the two cat5 cables joint together with a neutrik adapter with my Gld for 16 channels with no issues. I've never used all three together so far. I'd rather not buy nor rent a new 100m cable for a single gig, and was thinking about the possibility of doing 60 meters with cat cables and the other 30 with xlr's from the stage box to the speakers (three RCF Art710 for 60 people in attendance at moderate level)

How good are your solder skills?  If it were me i'd run this analog the whole way.  Either 2 300' XLRs [probably 6 100' cables] or i'd whip up a couple cat5 to Two XLR adapters.  Unless i'm misunderstanding what you're doing here.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Mike Caldwell on December 25, 2018, 12:50:37 am
How good are your solder skills?  If it were me i'd run this analog the whole way.  Either 2 300' XLRs [probably 6 100' cables] or i'd whip up a couple cat5 to Two XLR adapters.  Unless i'm misunderstanding what you're doing here.

Same here, kind of what I was leading up to with my questions.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Dan Richardson on December 25, 2018, 10:03:32 am
inside cable ramps over a grassy field.

Humidity trap. No big deal for an unbroken cable. Could play havoc with connections.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Andrea Litti on December 25, 2018, 10:17:55 am
Thanks again to everybody, I'll try to go with a single cable run. Oh, merry Christmas to all!
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Lyle Williams on December 25, 2018, 03:00:19 pm
Just about ever cable run in the corporate LAN world is three cables.  A patch lead to the wall outlet, a cable inside the walls/ceiling back to a wiring closet, and then a patch lead to an ethernet switch.

If it works on your garage floor it will work in the field.  If you want a plan B, run analogue over the cat5/6.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: William Schnake on December 25, 2018, 03:05:21 pm
Thanks again to everybody, I'll try to go with a single cable run. Oh, merry Christmas to all!
There is not 'Try' only do or do not.  Yoda Bill in the House!! 

Merry Christmas

Bill
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Kevin Maxwell on December 25, 2018, 03:28:09 pm
Just about ever cable run in the corporate LAN world is three cables.  A patch lead to the wall outlet, a cable inside the walls/ceiling back to a wiring closet, and then a patch lead to an ethernet switch.

If it works on your garage floor it will work in the field.  If you want a plan B, run analogue over the cat5/6.

Yes BUT most of this kind of cabling is using a completely different protocol then standard Ethernet. And is susceptible to all sorts of other problems. Most of it is UDP and Not TCP/IP and there is no error correction for lost packets like there is in TCP/IP.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Tim McCulloch on December 25, 2018, 10:57:26 pm
Yes BUT most of this kind of cabling is using a completely different protocol then standard Ethernet. And is susceptible to all sorts of other problems. Most of it is UDP and Not TCP/IP and there is no error correction for lost packets like there is in TCP/IP.

^^^ THIS.

Just because something uses CAT cable for transport does not mean that the OSI model is in use.  Suitability for one use does not indicate suitability for another use.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Brian Jojade on December 25, 2018, 11:42:05 pm
If it works on your garage floor it will work in the field. 

You could patch something together with tinfoil and coat hangers that might work fine in your garage, but once you get into the field, if it's not robust, that's when you'll see the weakness in the design.

An RJ45 connection by design is NOT very robust.  In a network closet, it gets connected once or twice, then stays there.  In the field, the connection is getting tossed around and reconnected repeatedly.  This means there's a much higher chance of failure vs something that is just going to sit there forever since new.

While you CAN have splices in your cable, it's pretty much always preferred not to have any in the middle of a run if it can be avoided.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Lyle Williams on December 26, 2018, 03:13:03 am
A&H dSnake is ethernet.

Errors on ethernet not due to issues like duplex mismatches are very rare.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Rob Spence on December 26, 2018, 02:03:15 pm
What connector is on the cat6? Neutrik has a different ethercon for cat6. I have heard they are not compatible and might not couple with the cat5e couplers.

I would never mix cat5e & cat6 cables in a single run. The twist ratios are different and would screw up the transmission line.

I believe A&H specs Cat5e. Using different may compromise your connection.



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Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Phillip Ivan Pietruschka on December 29, 2018, 06:53:36 am
What connector is on the cat6? Neutrik has a different ethercon for cat6. I have heard they are not compatible and might not couple with the cat5e couplers.

I would never mix cat5e & cat6 cables in a single run. The twist ratios are different and would screw up the transmission line.

I believe A&H specs Cat5e. Using different may compromise your connection.



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Neutrik Cat 6 ethercon is not compatible with the 5e or 6a variants, and mostly annoying. At least the 6a and 5e can intermate. Itís locking shell is similar to the Neutrik HDMI shell, and, I believe Opticon lite.

Iím sure Iíve mixed cat cable times many times without issue. For instance using installed cat 6 lines with 5e cables patches to it. At least in ethernet applications I havenít had a real world issue. Every single propertary protocol based on cat cables and 8p8c connectors sounds like a pain in backside compared to ethernet protocol that lives at OSI layer 4 or higher.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Rob Spence on December 29, 2018, 12:55:00 pm
Neutrik Cat 6 ethercon is not compatible with the 5e or 6a variants, and mostly annoying. At least the 6a and 5e can intermate. Itís locking shell is similar to the Neutrik HDMI shell, and, I believe Opticon lite.

Iím sure Iíve mixed cat cable times many times without issue. For instance using installed cat 6 lines with 5e cables patches to it. At least in ethernet applications I havenít had a real world issue. Every single propertary protocol based on cat cables and 8p8c connectors sounds like a pain in backside compared to ethernet protocol that lives at OSI layer 4 or higher.

I too have mixed types but never when close to the theoretical max distance. As mentioned, the coupler is two connections so takes 30í out even with matching 5e cables. Mismatching is sure to reduce the max safe length further.

Oh, Ethernet protocol is a low level one on the OSI stack, layer 2. Layer 4 gets you up to TCP/UDP.


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Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Lyle Williams on December 29, 2018, 10:01:19 pm
100m isn't the maximum theoretical distance for ethernet on twisted pairs.  It is a heavily de-rated distance to accomodate all the bad practices that happen in the real world.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Rob Spence on December 29, 2018, 10:34:29 pm
100m isn't the maximum theoretical distance for ethernet on twisted pairs.  It is a heavily de-rated distance to accomodate all the bad practices that happen in the real world.

It is a laws of physics (not suggestions) thing.
100m has been the published max number since orange cable and vampire taps.

It has to do with the timing involved in collision detection and retry timing.



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Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Rob Spence on December 29, 2018, 10:35:00 pm
100m isn't the maximum theoretical distance for ethernet on twisted pairs.  It is a heavily de-rated distance to accomodate all the bad practices that happen in the real world.

And where do you know this from?


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Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Lyle Williams on December 30, 2018, 02:36:58 am
I have been doing this for a living for a very long time.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Scott Holtzman on December 30, 2018, 02:51:11 am
It is a laws of physics (not suggestions) thing.
100m has been the published max number since orange cable and vampire taps.

It has to do with the timing involved in collision detection and retry timing.



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That part is true but since every port is it's own collision domain on a switch, and hibs don't exist anymore collisions are a thing of the past. 

All that being said a cable won't certify beyone 100M and I can't get paid without the test results and I have no interest in running a science fair project in field the spec is the limit.

 

Sent from my VS996 using Tapatalk

Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Lyle Williams on December 30, 2018, 02:56:56 am
Yes, no science fair experiments.  But the 100m spec is set with such a large safety margin that it always works without problems.
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Karel Noon on December 30, 2018, 04:49:11 am
Yes, no science fair experiments.  But the 100m spec is set with such a large safety margin that it always works without problems.

Always is a big word..... 

Iíd rather be safe than sorry!
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: James Paul on December 30, 2018, 07:31:02 am
These, along with some cat5e/6 STP, can make for a nice addition to a tool box.

https://www.proxdirect.com/products/view/4-Channel-XLR-M-CAT6-AudioDMX-Portable-Snake-Box-XC-SBCAT6-4XM
https://www.proxdirect.com/products/view/4-Channel-XLR-F-CAT6-AudioDMX-Portable-Snake-Box-XC-SBCAT6-4XF
Title: Re: Long distance cable runs and mixing different cat-x cables
Post by: Tom Slate on December 30, 2018, 02:43:28 pm
Has anyone noticed any difference or issues between 24awg and 26awg, with cat5e cabling? (the higher the number the thinner diameter.
I am seeking a 22awg 6metre cat5e cable for an application that deliveres power-over-ethernet as anything thinner can not deliver the current.
My dante setup doesnít rely on PoE but concerned on whether to choose 24awg or 26awg.