Wireless DMX has been around for more than a decade now. The idea is to use it when you cannot run a control cable from the lighting console to your lighting fixtures. For instance, you may have multiple lighting fixtures located on several rooftops and one console located in a van in a parking lot of one of the buildings.
The new Pro model of the W-DMX line is a third-generation device that outputs 275 mW of wireless signal power. The device is simple. It connects a universe of DMX directly from the console to a small black transmitter using 5-pin XLR cable. The transmitter then sends the DMX through the airwaves to a receiver box. The receiver then spits out the DMX through the same XLR connector into a cable connected to your dimmers or lighting fixtures. Each Pro model powers up one universe of DMX.
The Wireless Solution black box Pro model can act as either a transmitter or a receiver. A switch on the back tells each unit whether to send or receive DMX. An LED on the front tells the user which mode the black box is currently in. There is a green bar graph on each unit so you can see that the receiver is indeed getting a signal and tell how strong it is. They are small devices with a 4-inch antenna. Each box can take 90-250VAC volts to power it up. The device also can be powered by 12 volts DC; perfect for a car. It also has a built-in battery that can be turned on by an external switch. The battery is charged when DC is applied and can run for up to eight hours. (I let it run for 24 hours before it ran out). There are some tiny brackets you can use for mounting these units to a truss as well. You can use multiple receivers with one transmitter.
A Hop, Skip and Jump
The biggest problem with transmitting wireless DMX has always been that the transmitter and receiver must be in a straight unobstructed line of sight from each other. This meant you needed to have multiple transmitters and receivers in one continuous loop to send the signal around the corner of a building. With this unit I did not have to do this. I set up the transmitter next to my console in the control room, enclosed by half-inch glass and brick. There was about 1/16-inch of space under the door. The receiver and light fixtures were located on the other side of the window, and the lights functioned flawlessly.
Next, I pushed the light fixtures 200 feet away from the control room and out of the line of sight. Again, the device worked flawlessly. So I pushed the fixtures around a corner and placed them 500 feet away from the control room. It still worked. It’s getting interesting now. I pushed the fixtures outside and closed the garage door tightly. They still worked. It’s time for the next test.
I went out to my car and connected the transmitter to a cigarette lighter. It worked. I then attached a Goddard Lil’ DMXster (portable battery-operated DMX tester), and I sent the signal through the closed window to the fixtures located in the shop. They stopped working. Fair enough. I was now 600 feet away and trying to transmit the signal through three separate layers of brick and glass. So I rolled down the car window and stuck the antenna outside. The fixtures started moving, but with a little quirkiness, as they were not getting a full signal. But this was far better than any other device I have ever used before.
W-DMX is different than other systems on the market. Most of their competitors rely on a proprietary standard Wi-Fi or W-LAN (wireless local area network) to transmit the signal. W-LAN is designed for use in office or domestic environments, and it uses fixed channel frequencies that can encounter interference in signal. Wireless Solution uses a type of spread spectrum transmission known as adaptive frequency-hopping spread spectrum. It avoids noise and interference by changing its frequency 1000 times per second, but never to a frequency being used by other equipment on the same frequency band. Channels that are being used by other equipment are identified and purposely avoided. This is great because the units are virtually “plug and play.” There are no frequencies to change for a nontech like myself. Frequency Hopping Technology was developed by the military to make it hard for other people to jam the signal. It’s also the same technology used by Bluetooth.
Hitting the Wall
Any wireless signal can encounter obstructions. Concrete is usually a bad transmitter, but it did not seem to have an effect in this case. Water is the biggest challenge. The wireless signal simply cannot pass through a human body. So if you are in a concert environment with lots of people, you should mount the receiver and transmitter above the heads of the crowd. The signal can safely transmit a DMX signal a distance of 1300 feet. But if there is rain or snow in the air, the distance shortens.
In addition to the single Pro model, there is also a black box repeater that boosts the signal. It’s made for outside weather. Say, for example, you have lighting fixtures mounted on 10 different faces of one building. You could use the Pro model to send DMX to all four corners of the roof and a repeater hanging slightly over the edge of the roof to send the signal down several hundred feet to other fixtures. Placing these repeaters on every corner of the building pretty much insures that the signal will never drop out en route to its receivers.
The Pro model also supports ACN and Art-Net. It has an IP rating of 65, which means it can stand up to dust and low pressure jets of water from any direction. The manufacturer says it should be UL listed this summer. There is no IP address or net mask; this is why it’s plug and play. There are different antennas you can purchase for use outdoors. You can also order cables of various lengths to separate the antenna from the black boxes. The unit is not affected by Bluetooth, cell phones or any other wireless device. You can use as many receivers as you wish; the only limit is that you can’t exceed 512 channels of DMX. Of course, it is possible to have multiple transmitters, one for each universe of DMX the console is using. This system can transmit 16 separate DMX universes at one time (8000 DMX channels). The receivers will stay “locked on” to the transmitters even if DMX signal to the transmitter is temporarily lost. They also manufacture a smaller “booster” box for shows that require a DMX signal to travel for distances exceeding 1300 feet.
I’ve used wireless DMX from different manufacturers several times with mixed results. Wireless Solution Sweden AB, a relatively new name in network routers and other wireless devices, has entered the lighting business to help solve the problems designers have encountered with this technology in the past. With the WDMX line, they have successfully tackled these problems.
What it is: Wireless DMX transmitter/receiver
What it’s for: Distributing DMX data to a system where hard wiring is challenging or impossible.
Pros: Plug and play, simple to use, transmits or receives, doesn’t need line of sight, low noise and interference
Cons: None that we can find
How Much?: $1395 MSRP
