Hello,
I was doing a service call at a local DJ nightlclub testing their subs/amps, and encountered a strange issue:
One of the staff demonstrated a recently developed problem:
When their is no music/audio running through the system, there is a pretty loud hum (not noticeable once music is playing, but the club also has day-time brunch events etc without the music pumping) coming through what seems to be all the speakers. I didn't check the first floor speakers for the hum, but all the speakers on the second floor where the DJ booth is located had them (passive EV ZLX-12/similar speakers run from Dynacord amps and a Rane ZonePro processor).
What's strange is, the tone/level of the audio hum changes as he uses the lighting control iPad to change colors and patterns through their ADJ MyDMXGo system. They have cheap LED movers/pars flown throughout the club ceiling along with the EV mid/high speakers, I didn't do the install so don't know where all the wiring runs are.
In the DJ booth with the lighting control iPad/MyDMXGo box, the DJ controller and a laptop run into a cheap Alto analogue mixer (with a DC wall wart, the mixer is ungrounded), from their into dual XLR inputs on the wall and from their up to the processor.
When I unplug the XLR mains running into the wall plate or power off the anologue mixer, the level of the hum goes down, but is still present at a lower level and still fluctuates when the light colors/movements change.
tl:dr - when the nightlclub lighting system has color/movement/scene changes, a hum in the sound system changes in tone and intensity even with the main input to the system disconnected at the DJ booth.
If any of you ran into this, what would you look into to address it?
My immediate thoughts:
-Audio equipment sharing a circuit with lighting equipment
-maybe one of the ground wires from a balanced euroblock connector got disconnected from the processor inputs.
-the noise must be getting induced somewhere after the XLR wall plate because it remains even if the main inputs are disconnected
-unplug speaker drive lines from the amps to see if the noise is on the speaker lines or the XLR input line
Any help or suggestions are greatly appreciated! Hope this was typed coherently enough to be comprehended.
Thanks,
Douglas Cyr
I was doing a service call at a local DJ nightlclub testing their subs/amps, and encountered a strange issue:
One of the staff demonstrated a recently developed problem:
When their is no music/audio running through the system, there is a pretty loud hum (not noticeable once music is playing, but the club also has day-time brunch events etc without the music pumping) coming through what seems to be all the speakers. I didn't check the first floor speakers for the hum, but all the speakers on the second floor where the DJ booth is located had them (passive EV ZLX-12/similar speakers run from Dynacord amps and a Rane ZonePro processor).
What's strange is, the tone/level of the audio hum changes as he uses the lighting control iPad to change colors and patterns through their ADJ MyDMXGo system. They have cheap LED movers/pars flown throughout the club ceiling along with the EV mid/high speakers, I didn't do the install so don't know where all the wiring runs are.
In the DJ booth with the lighting control iPad/MyDMXGo box, the DJ controller and a laptop run into a cheap Alto analogue mixer (with a DC wall wart, the mixer is ungrounded), from their into dual XLR inputs on the wall and from their up to the processor.
When I unplug the XLR mains running into the wall plate or power off the anologue mixer, the level of the hum goes down, but is still present at a lower level and still fluctuates when the light colors/movements change.
tl:dr - when the nightlclub lighting system has color/movement/scene changes, a hum in the sound system changes in tone and intensity even with the main input to the system disconnected at the DJ booth.
If any of you ran into this, what would you look into to address it?
My immediate thoughts:
-Audio equipment sharing a circuit with lighting equipment
-maybe one of the ground wires from a balanced euroblock connector got disconnected from the processor inputs.
-the noise must be getting induced somewhere after the XLR wall plate because it remains even if the main inputs are disconnected
-unplug speaker drive lines from the amps to see if the noise is on the speaker lines or the XLR input line
Any help or suggestions are greatly appreciated! Hope this was typed coherently enough to be comprehended.
Thanks,
Douglas Cyr