Remote Audio CAT-5 Video Assist Kit

For the sound cart, a typical video assist setup often requires four channels: two video and two audio. Two video lines are so that the sound mixer can see two cameras, one audio line is to send a mix to the video assist operator, and the second audio line for playback from video assist.

Until recently, the best method involved a heavy, bulky, and expensive snake with two shielded audio pairs and two video coax pairs with BNC connections that were prone to failure. Those days can now be over.

The CAT5 cable in the Remote Audio CAT-5 Video Assist kit has stranded conductors to be flexible and lay flat.

Now, all four channels can be handled with a simple and inexpensive CAT5 Ethernet cable that will provide a high quality picture and noise-free audio for well over 1000 feet. All that’s needed is a small transformer adapter box at each end of the cable. Since the adapter boxes are passive, they can be used as either inputs or outputs. An added advantage is that the transformers provide ground isolation between the sound cart and video assist cart, eliminating buzzes and annoying shocks from voltage potential of the past.

I had heard of a few Sound Mixers experimenting with this type of system, but didn’t fully appreciated the benefits until I put one together myself for a feature film I worked last fall. The heart of the system is a pair of small (2 inches square) “baluns” type transformer boxes with four circuits (two video, two audio). One box was velcroed onto the side of the sound cart and the other is velcroed to the video assist cart. The audio and video connections on the transformer boxes are female, so a short adapter harness is used with two connectors for video and connectors for audio (BNC, RCA, or XLR, as needed). For the duration of my production, the two boxes remained on their respective carts. To connect two audio and two video channels, all that was needed was to plug in a single Ethernet cable.

Of course, Ethernet cables can be found ready-made from Radio Shack to Comp USA to Home Depot. However the CAT5 cable in this Remote Audio kit has been specially chosen because of its flexibility. The stranded conductors and pliable jacket allow the cable in this kit to lay flat and to be coiled like a mic cable. Also, the connectors have a special shield that keeps the release button from snagging on set debris as the cable is being pulled through the set.

I found that a 100′ cable was always enough on my production, but if more length is needed, modular CAT5 barrel adapters allow cables to be extended as needed. The system allows distances of up to 1000 feet or more, but 200 feet is almost always enough and is still very lightweight and easy to manage. TIP: The time-honored technique of “over-and-under” cable coiling is highly recommended.

Even though run-of-the-mill CAT-5 cable may seem very small and light to carry 4 channels, used my 100′ cable every day for five weeks on a feature without a single failure, and it’s still good to go for the next production.