Using Category 5/5e/6 for Audio and Video Applications

[JRT]

While looking at maybe using some Cat 6, maybe shielded Cat 6, for
short AES3 interconnections between Lynx AES16E-50 and RME ADI-6432,
I ran across a paper that I thought others might find useful.



Here is the link:

https://secure.connect.pbs.org/confe...AV.Handout.pdf



Here is the abstract:

Using Category 5/5e/6 for Audio and Video Applications

Steve Lampen
Multimedia Technology Manager
Belden Cable

ABSTRACT
With the rise of premise/data cables, such as Category 5, the possibility of using such cables for non-data applications was suggested. Now it is common to find Category 5, Category 5e, or Category 6 routinely used in many alternate applications. This paper will concentrate on audio and video applications, both analog and digital, with emphasis on whether UTP data cable can meet the requirements of these systems, and what limitations there are.

[dcibel]

Re: Using Category 5/5e/6 for Audio and Video Applications

http://www.rane.com/note149.html

It would appear from this that CAT5 is perfectly acceptable and often used for AES2 connections. Just be sure whatever interconnection method you use, that the cable and connectors used are of the correct impedance for your application.

[JRT]

Re: Using Category 5/5e/6 for Audio and Video Applications

http://www.rane.com/note149.html


It would appear from this that CAT5 is perfectly acceptable and often used for AES2 connections.

There is also Appendix 2 in the AES/EBU spec.

https://tech.ebu.ch/docs/tech/tech3250.pdf

SPECIFICATION OF THE DIGITAL AUDIO INTERFACE (The AES/EBU interface)

Tech. 3250-E - Third edition - 2004

1. Scope

This document specifies a recommended interface for the serial digital transmission of two channels of periodically sampled and linearly represented digital audio data in a broadcasting complex, up to a distance of a few hundred metres.

Although this transmission specification is independent of sampling frequency it is intended that the interface be primarily used at 48 kHz, as this is the recommended sampling frequency for use in broadcasting studios (CCIR Recommendation 646).

The document does not cover connection to any common carrier equipment nor does it specifically address any of the questions relating to the synchronising of large systems, although by its nature the format permits easy synchronisation of receiving devices to the transmitting device.

Specific synchronisation issues are covered in document AES 1l-l991.

Note 1: In this interface specification for broadcasting studio use, mention is also made of an interface for consumer use. The two interfaces are not identical.

Note 2: An engineering guideline document to accompany this interface specification is in course of preparation by the EBU.

2. Interface format

{snip}

Appendix 2 - AES/EBU signals on Structured Wiring

There is an increasing use of structured wiring for carrying AES3 signals. Notwithstanding clause 6.1, the practice has been shown to be viable on Category 5 unscreened pairs, meeting EMI requirements, and offering transmission up to 400 metres overall unequalised, or 800 metres equalised, at 48 kHz frame rate. For a satisfactory outcome, this practice should only be used where the whole length of the connection uses Category 5 UTP (Unscreened Twisted Pair) cable, including that which is installed and any flexible leads (equipment cords), and that the connection is unscreened for the whole length. Alternatively, the whole length of the connection should use Category 5 STP (Screened Twisted Pair), and the connection should be screened for the whole length. Care should be taken in design of the interface to provide adequate balance on the twisted pair within the Cat.5 cable.

Using RJ45 connectors, conventionally wired, current practice favours the use of pins 4 and 5 for AES/EBU signals (separating them from ATM signals on the same cable). Pins 3 and 6 are the preferred second pair. Note that, for full protection, the interface may have to withstand power voltages specified to support network equipment, and the use of transformers and blocking capacitors on the AES/EBU interface is strongly recommended. Suggested practice: while the interface is by definition insensitive to polarity, for the purposes of constructing adaptors, XLR Pin 2 should be connected to RJ45 Pin 5 (or other odd-numbered pin), XLR Pin 3 should be connected to RJ45 Pin 4 (or even-numbered pin).

[JRT]

Re: Using Category 5/5e/6 for Audio and Video Applications

Just be sure whatever interconnection method you use, that the cable and connectors used are of the correct impedance for your application.

Yes, else reflections on the interconnection.

[JRT]

Belden video on demonstration of bonded pairs:

[JRT]

Dave Rat's video demonstrating a comparison of various lengths of mic cable, AES cable, snake cable and Cat 5 cables with AES3 at 48, 96 and 192 KHz sample rates.

[JRT]

Dave Rat's video demonstrating practical effects of a large number of terminations, stringing a large number of short patch cables in series with the longer cable.