Behringer X32 bus 1 noise

J

Jason Johnston

Freshman
Jan 26, 2015
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I am new to the X32 and so far with initial setup I am happy. I run sound for my local church and have been using a Soundcraft LX7 for many years. So far all is ok except for a constant hum in my on stage monitors. I am using the bus outs for the monitors. I can mute everything and I still get the hum. It also does not change with the volume control if I go up or down, just a nice constant hum. I am sure it is probably a setting, just not sure where to start.

Thanks,

Jason
 
Re: Behringer X32 bus 1 noise

Sounds to me like it's not the mixer at all, but rather your cabling or signal chain into the monitor amps.
 
Re: Behringer X32 bus 1 noise

It was not a noise I had with the old anilog board, it only showed up with the new digital board. That is why I assumed it was a setting issue.
 
Re: Behringer X32 bus 1 noise

If you mute the output and it's still there, I'm not seeing the board. What about if you unplug the cable from the board, do they pipe down then?
 
Re: Behringer X32 bus 1 noise

I just did the checks you mentioned, and if I mute it stays, if I unplug, the hum goes away. And thanks for your reply, I appreciate your help, I need it!
 
Re: Behringer X32 bus 1 noise

Jason Johnston said:
I just did the checks you mentioned, and if I mute it stays, if I unplug, the hum goes away. And thanks for your reply, I appreciate your help, I need it!
Click to expand...

Sounds like a good old-fashioned ground loop. Are the monitors (or their amps, if passive) and the board on different power circuits? Is it an older building? Try running an extension cord to the monitor from the same outlet as the board and see if the hum goes away. I've lost track of the number of times I've had to run extension cords across a venue to fix exactly this problem.
 
Re: Behringer X32 bus 1 noise

Simon! You are DA BOMB! I had just had a wild idea to put a direct box on the out put of the board and it worked! I just logged in here to tell of the fix or problem identified and seen your post, because I fixed or bandaided the problem but was unsure of the fix. You are correct on two of your diagnosis, 55 year old building, and not only separate circuits, but separate breaker boxes, its a large long building with multiple breaker boxes. So other then a long extension cord all the way across my church, how can I fix this? Again, thank you for the diagnosis!
 
Re: Behringer X32 bus 1 noise

Jason Johnston said:
Simon! You are DA BOMB! I had just had a wild idea to put a direct box on the out put of the board and it worked! I just logged in here to tell of the fix or problem identified and seen your post, because I fixed or bandaided the problem but was unsure of the fix. You are correct on two of your diagnosis, 55 year old building, and not only separate circuits, but separate breaker boxes, its a large long building with multiple breaker boxes. So other then a long extension cord all the way across my church, how can I fix this? Again, thank you for the diagnosis!
Click to expand...

Transformer isolation is the standard approach.
 
Re: Behringer X32 bus 1 noise

Agreed, and I should have mentioned that before as an alternative. I usually just end up running a power cord to FOH as there is usually more than one connection to isolate, and for a temporary install it's just easier, but for a permanent install, any of the devices described above should do the job. Radial make a good dual-channel one also. As you already found, you can get the same effect with a DI box (probably with the ground lift switch flicked) but to maintain the balanced connection to the amps you really need the dedicated XLR/600ohm-both-sides isolator.
 
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