LED Lights Fixtures buzz Sound system

I remove some ceiling fans and switches and installed Led (dimmable) can lights fixtures with a dimmer in their place at our new church building. When the LEDs are on you can hear a buzz in the sound system. The sound system was in our previous church building and worked fine with the florescent fixtures there and the florescent fixtures in the new building don't buzz the sound system. Anyone have suggestions?
 

GoldDigger

Moderator
Staff member
Check whether any sound system wires run in same raceway with or parallel to wires from dimmer to lights.
Consider putting filtering on input side of dimmer(s).
Possibly poor grounding/EGC practices.
First step is to determine how buzz is getting into audio system.
 

kwired

Electron manager
Location
NE Nebraska
Maybe the type of speaker wire used is a contributing factor. Twisted pair doesn't pick up the RF interference that non twisted pairs will.
 

grich

Senior Member
Check whether any sound system wires run in same raceway with or parallel to wires from dimmer to lights.
Consider putting filtering on input side of dimmer(s).
Possibly poor grounding/EGC practices.
First step is to determine how buzz is getting into audio system.
Start by killing all input pots on the sound system mixer to see if you can make the buzz go away. If you find the culprit, start looking for unbalanced circuits, ground loops, etc.

If the buzz is still there and the mixer is separate from the power amp, kill the input to the power amp.
 

tbakelis

Senior Member
I'm really frustrated lately by these LED installs. I continue to run into buzzing coming from LEDs that are being dimmed. Most recently I installed 70 halo 3500K LEDs in a house in which half seem to buzz. Can someone tell me what the solution is? I've been using the led diva style dimmer sold at HD. Someone told me to use a magnetic dimmer... At $50+ a pop... It better work before I tell the customer that is the fix! Help!!
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
I'm really frustrated lately by these LED installs. I continue to run into buzzing coming from LEDs that are being dimmed. Most recently I installed 70 halo 3500K LEDs in a house in which half seem to buzz. Can someone tell me what the solution is? I've been using the led diva style dimmer sold at HD. Someone told me to use a magnetic dimmer... At $50+ a pop... It better work before I tell the customer that is the fix! Help!!
Which led cans - Halo? 4" 6"
 

GoldDigger

Moderator
Staff member
I'm really frustrated lately by these LED installs. I continue to run into buzzing coming from LEDs that are being dimmed. Most recently I installed 70 halo 3500K LEDs in a house in which half seem to buzz. Can someone tell me what the solution is? I've been using the led diva style dimmer sold at HD. Someone told me to use a magnetic dimmer... At $50+ a pop... It better work before I tell the customer that is the fix! Help!!
Some dimmable LED drivers are only sensitive to changes in RMS voltage while others are specifically made sensitive to a phase chopped (triac/SCR) waveform.
Before you invest in a magnetic dimmer, find out how your fixtures will respond them. You can get an idea by feeding the fixture from a Variac (TM). Some will show almost no change in light output versus voltage all the way down to the point where they start to flicker. :(
 

hbendillo

Senior Member
Location
South carolina
Although LED lights can be dimmed with conventional dimmers, there can be a compatibility problems. When I specify LED fixtures in a commercial setting the fixtures include a special driver to match up with 0-10 volt dimmers. Maybe the incompatibility is causing the noise.
 

mirawho

Senior Member
Location
Sun Valley, CA
I'm really frustrated lately by these LED installs. I continue to run into buzzing coming from LEDs that are being dimmed. Most recently I installed 70 halo 3500K LEDs in a house in which half seem to buzz. Can someone tell me what the solution is? I've been using the led diva style dimmer sold at HD. Someone told me to use a magnetic dimmer... At $50+ a pop... It better work before I tell the customer that is the fix! Help!!
When installing LED lights, you really have to read up on the specs. A lot of lights, like the Halos, are best dimmed with an electronic LED rated dimmer. They will tell you that you can use an incandescent dimmer, but you are better off with an electronic one.
 

mirawho

Senior Member
Location
Sun Valley, CA
Ronnie, why don't you use a UPS/Conditioner to supply the audio board? I am not sure what your audio configuration is, but if you have a mixer, amp/s, mics and some playback source, I can't imagine you using more than 2 - 20@ circuits. 20@ conditioners aren't too expensive and it would probably solve your problems.
 
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