Times wireless DMX has failed

ShowNet

Member
I'm catching up on a couple months of posts, and I particularly enjoyed this discussion on wireless DMX - https://www.controlbooth.com/threads/wireless-dmx.44193/

Something I would love to hear is the times where wireless DMX DIDN'T work as planned. This isn't to diss on the manufacturers, who make great products that meet a great need. But we all learn more from failure than from success. And wireless has some tricky points of failure.

So I'm curious what setups worked 99 times and then just failed on that 100th time, or worked great in rehearsal but not when the house was full, or worked until the welder across the started welding, etc.
 
I’ve had a no name brand wireless DMX that stomped all over my RRFU. No channels were available and made the RRFU useless for a focus of a large conventional rig. I had to go shut down the wireless to get done, made it painful. When the event returned the following year I refused to setup the wireless, ran cable instead.
 
I’ve had a no name brand wireless DMX that stomped all over my RRFU. No channels were available and made the RRFU useless for a focus of a large conventional rig. I had to go shut down the wireless to get done, made it painful. When the event returned the following year I refused to setup the wireless, ran cable instead.

Anytime you are playing in the 2.4ghz spectrum things can get bad quick. Same things goes for 5.8ghz. One bad radio or one radio transmitting at a slightly higher power can pretty much kill the entire thing.
 
Like transmitter mics, what works during rehearsal may not work at showtime. As audience members carry more and more gizmos that are trying to link to something, the spectrum gets crowded. Remember, each device has a frequency it operates at, plus harmonic spikes at other frequencies. Once you have more than one, you also get sub-harmonics. (Think beat patterns when you are tuning a guitar.) If you have a room full of devices, the RF spectrum starts looking like trash.
That said, ALSO like transmitter mics, if you pay good bucks for something decent, it is more likely to find its way around the RF trash and actually work!
 
That said, ALSO like transmitter mics, if you pay good bucks for something decent, it is more likely to find its way around the RF trash and actually work!

I would say I'm particularly interested in the times where even the "good bucks" doesn't work. I'm a gearhound who tends to go for the quality stuff that "just works" as opposed to fussing around with cheaper and less optimized solutions.
 
I'm an old guy who is highly skeptical of things wireless... I told Marconi that he was wasting his time and now I see you young'uns carrying on with his folly. What's next, radio with pictures? Kids these days, I'm telling you... /satire

Seriously, I'm a skeptic for a reason - I've witnessed and been a party to enough RF problems in close to 40 years in audio/performing arts. In complex situations, unless one is an RF tech the expectations need to be managed, not promised. That's something clients don't really want to hear.

Like you, I'm more interested in failure modes, causes and fixes than pointing fingers or naming names but learning what happened when Really Good Stuff wasn't good enough for the situation du jour, and how it was dealt with is why we're here.

Most of the reason wireless DMX or audio work so well is because the designers do a really good job for the target price of their products, but what they cannot do is _fully_ anticipate the RF operating environment their products will be subjected to. That almost every person in the audience has both a computer and multiple RF transmitters on their person is an issue that will only get worse as more RF spectrum is inevitably assigned to those types of devices.
 
Blizzards wireless are nice but are 2.4ghz. They were installed against me saying 2.4 wouldn’t work in our arena. Luckily for me they controlled flash n trash so if it lost control it flickered and looked the same.

They have a few different channel ranges but the best thing was when people tried to use the WiFi with older devices that was only 2.4 and the internet would cut out and they would get mad.

I would laugh at them at say I told you it was going to happen. That conversation never went well but when handed a solution to spend money to fix it the conversation ended lol.
 
I would say I'm particularly interested in the times where even the "good bucks" doesn't work. I'm a gearhound who tends to go for the quality stuff that "just works" as opposed to fussing around with cheaper and less optimized solutions.

I would find some sites that the film and TV studio electricians hang out in. I had a conversation a few years back with a Local 52 guy about how packed the studios get with WiFI this and WiFi that. EVERYBODY wants WiFi and a lot of folks have issues trying to run things like iRFR in a studio. I’d be curious if anybody relies on WiFi DMX.
 
As an example of 2.4 GHz problems, I'm pretty sure my panasonic microwave is a giant CRTC violation given that it frequently disrupts all my other 2.4GHz communications when cooking. (i'm not sure i want to know how much power is escaping)

While a leaky microwave probably isn't close enough to the rig to cause an issue, it is an example of how a faulty device can block effective use of a given spectrum. That's the catch 22 of any license-free spectrum, you're going to have a WIDE range of devices of varied quality and condition trying to talk at the same time.

Aside from some eerie wireless mic problems we've had, the most notable instance where 2.4 GHz congestion actually caused some production annoyance for me has to be when we were using integrated Bluetooth on a board so we could sit somewhat remotely while still having audio control. This worked flawlessly until the flock of iphone-toting dancers walked into the auditorium, at which point the audio was stuttering and dropping connection like mad.
 
When the Show Baby first came out, we were demoing one in our warehouse for a trade show. It totally shut down our 2.4 wireless network. My suspicion is that it was a bad transmitter, but it definitely makes me twice as cautious about using wireless for anything.
 
I have a couple of good ones. Actually just posted one on another wireless thread.

#1 Equipment: Wireless uplights, and Show Baby 6 as transmitter.

They worked all over the venue except in one event room. The used them in larger rooms with no problem this room was maybe 40'x40' and they would not work. Turns out there were 3 industrial grade AP's in the room at full transmit strength. We had IT turn 2 of them off and everything worked fine.

#2 Equipment: SHoW DMX Neo Transmitter and Receiver

Transmitting from a chase car to the hero car. Had control of the system after adding a 2.4 booster (technically not allowed). Booster was added because of the camera transmitting on 2.4 and over powering everyone. receiver would loose connection every time the hero car when under a specific bridge. Turned out there were camera's for traffic monitoring that were also transmitting in 2.4. There was no way to turn them off or boost signal anymore so they cued around the problem.

These are some signal issues, most of the problems we see are user error. Putting transmitters on top of each other, behind glass, under the stage. The glass one is interesting especially if you live in a warmer climate, the insulated glass has a layer of metal to help with insulation. That will cut your wireless signal down very quickly.

Not me but a story told to me about wireless. This was in the early days of wireless. There was a lot of wireless being used by all departments. Lighting was having problems with staying connected, turns out everyone had boosters on their wireless. The electrician on the project asked if they could workout a signal plan to work together. Every other department said why should we change ours it is working you just fix yours. He went out and got a bunch of boosters and more transmitters effectively shutting down the other departments wireless systems. They then came up with a wireless plan the next day...

The last part is the most overlooked problem. Most aren't planning out their wireless as a production, as stated before all it takes is one bad transmitter be that for the production or FOH's wireless printer and everything can come crashing down.
 
I think the most instuctive stories are the ones you won't hear. I mean those where a wireless survey turned up a major issue. Even if was solved later rather than just abandoned, the details of what caused the issue would tell the most.
 
Not DMX, but I was doing an immersive show in Beijing with a flying rig from a reputable US provider. It was all wired except for one wireless component. All working great until the venue switched on the wifi (for which we had been desperate for weeks). Faulted the rig every time. The guys said they had never seen that before, but you know: China. We opened the show with building wifi shut down, and the flying team had to stay an extra week to solve the problem.
 
With the units that autodetect if they should be a transmitter or receiver, accidentally triggering two devices to transmit.

Then finding the offending fixture that is transmiiting on the DMX cable that leads to that unit...
 
I used to be a proponent of wireless DMX but now have a better respect for the frequency spectrum used by w-DMX and wireless microphones.

I've been working with a rural high school to upgrade their 700 seat auditoriums, circa 1080, lighting system. We've been adding a section each year over the past few years. They first complained that the lighting from the portholes above the audience was insufficient. They added a section to the front of the stage pushing the stage about 6' closer to the first row of seats. This caused the overhead light down angle to be about 60 degrees instead of the designed 45 degrees on the stage popper. This caused the actors at the front of the stage addition to be poorly lit. I suggested we add a lighting ladder truss on either side of the auditorium at a lower angle to better light the actors. They agreed to the plan. I added 6 DMX dimmers to each side and a combination of 4 PAR 64 cans @ 1kw (throttled @ 80%) & 2 ellipsoidal's per side. Cans for RGBA wash & Leko's for special spots. Rather than pull a DMX cable I though I'd use w-DMX to operate the additional 12 channels using the chauvet w-DMX kits with a DMX onto isolator, (1 in - 4 out) in the booth. 1 out to the built in lighting system and 1 out to the WDMX transmitter. This setup has worked great.

Last year I added LED lights to the 3 stage electric batons. Since each LED LIGHT has its own controller I just needed to run power & DMX to them to operate them. Since I already has WDMX working great running those channels out front I decided to just put additional receivers on each baton to deliver the DMX signal to the LED lights on the baton.

We did the install and upon testing everything was working fine. During the annual Muscial stage production I suddenly noticed one of the LED lights shut off on its own. Then about 30 seconds later it came back on. This kept happening. I noticed it happen to what appeared to be other lights as well. After the show I turned on all of the LED lights and went on the stage and watched for a light yo turn off...never happened. But again the next evening it started again during the performance. This went on through the shows run. No one else noticed it until I pointed it out to the crew.

Then finally while checking the system out I noticed an entire baton of LED lights shut off and come back on...what? As I just waited I noticed each of the batons eventually do the same. I replaced the receivers. No change..but the lights out front were rock solid on the same signal??? I analyzed the transmission line of sight and the only obstruction the stage receivers had was the grand curtain. The receivers for the lights out front are in the attic with several walls in the path and the ceiling of the auditorium hanging on a corrugated steel plate that I'm sure in grounded. The stage receivers are about 30' farther away, but still no more than 150' line-of-sight.

I tried a variety of things with no luck. I even added a 20' cable to the WDMX receiver on the 1st baton bringing it to the stage floor but the behavior continued. By that time I'd spent so much time troubleshooting this that I gave up and pulled a cable from the booth, up and through the attic, then drop to the stage, 300', but the stage LED Lights are working properly now.

So now I'm less keen on WDMX and will use it more sparingly in the future.
 
So now I'm less keen on WDMX and will use it more sparingly in the future.

This is the kind of situation that interests me greatly. I'd come check it out at my expense. Stuff like this, when resolved, is what leads to really good next-generation stuff. That's my job.

Was it literally W-DMX, which is a registered trademark of Wireless Solution? Or RC4 gear? Show Bs? LumenRadio? Totally cool if you don't want to divulge that. But if it was us (RC4), totally cool calling me out. We're here to help and I'd like to fix this for you. I can assure you we can make a 700 seat HS aud work flawlessly. I help out at a local HS to ensure this. My daughter was a tech there until last year. :)

Jim
RC4
 
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I've been working with a rural high school to upgrade their 700 seat auditoriums, circa 1080, lighting system.
We did the install, I'll use it more sparingly in the future.
@taneglaus What impresses me most is your original system dating from 1080! I'd find 1980 far easier to believe but having any portion of a system from 1080 still in service is phuqin impressive. Are you still wicking whale oil to your sources?
Toodleoo!
Ron Hebbard
 
We had a designer come in for a show that wanted to add color to the houselights at a large regional theatre. The building wouldn't allow them changing the lamps in the architectural sconces, so the designer added 24 3" fresnels within the wall to shine up at the wall sconce. Those plugged into an orchestra stringer and into a small dimmer pack with ShowBaby wireless DMX.
So 24 lights in 8 locations and show baby to control.
What would happen every other show or so is when house would go to half, none of the colored lights would fade out. Then randomly into the act, they'd blink out.
Every time, they'd be ok fading up, I assume because everyone's phone had been in their pocket for an hour during the show, but fading out was always a mess.

Second story was a corporate event at a rooftop bar with a bunch of wireless chauvet uplights.
Because it was corporate, it was like $100 per light rental for the group, so waaaay too much money.
When the event was to start, all the lights died. This was the final death for this system. Couldn't get it back up and going again and since it was fairly cheap to replace them all.
 
I'm, I appreciate your very generous offer. The wireless kits are not RC4. I installed this 3 years ago with much water under the bridge since. I thought they were WDMX kits... But not absolutely sure. I know I initially had the cheap silver tube direct plug-in receivers but pulled them and replaced with a little black box with a short DMX cable coming out...I can't think of the brand name but I thought it was the WDMX system.

At this point we've moved passed this issue, I don't want to spend any more of my time on this and getting the school to spend more $ on a contract they've already payed is unlikely. But I'd like to keep your info and we'll see what happens in the future.

You know when your troubleshooting somethings there's always something you think you might have missed. And in my description I forgot to say why I focused on the wireless receivers. Initially with those silver stick receivers they have an led on the top that shows its status. I noticed that when the baton shut off the status of the receiver was not connected and when the baton came back on the receivers status showed it was connected. Again, 3 receivers behaving this way. Knowing those stick receivers are cheap,mi replaced them with (what I believe to be) WDMX receivers thinking the issue might be the cheap receivers. But the problem persisted. On the receivers display it showed no signal when the baton would shut off and when it came back on it showed there was a signal. I never changed the transmitter as the 12 dimmers out front were working fine off of the same signal/transmitter.

Thinking about this though, I haven run the wired LED lights full bore yet. That won't happen until the winter. If the problem persists with hard wire DMX then I'll have to look at the DMX signal path...but I hope not...
 
Yeah Ron, this is some hearty equipment...reminds me of the Flintstones...Dino running on a treadmill outside the auditorium, or Fred Squeezing a taradactile who would light or squish a candle - candle power! You know I meant 1980.
 

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