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.