Newb- Looking for some direction.

Re: Newb- Looking for some direction.

Jeff Sebers said:
Agreed, we are looking for the real problem before changing anything.

they are all 1/4 inch with one band on the plug. So I'm guessing an unbalanced signal.

The monitors only have the 1/4 input in them.
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Important: what are the monitors exactly? If they're passive cheapies, the 1/4" jack will be speaker level from a power amp and a balanced input line level signal would not be applicable.
 
Re: Newb- Looking for some direction.

Jeff Sebers said:
on another note, we rented a board while ours was getting looked at/cleaned and we had no humming. Frustrating issue for sure. Local av company we work with suggests new board.
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That's a pretty key piece of info..
Two quick thoughts:
1: did the loaner board have different connectors and perhaps they used different cables (balanced?) to connect it to the EQ/Amps?
2: if you only have hum from the monitors, try swapping the main outputs with the monitor outputs and see if the hum moves to the mains or sticks with the monitors..

you probably have a wiring (signal wiring) issue.. if the board was the actual source of the hum it would probably be coming out of every output

Jason
 
Re: Newb- Looking for some direction.

Greg Cameron said:
Important: what are the monitors exactly? If they're passive cheapies, the 1/4" jack will be speaker level from a power amp and a balanced input line level signal would not be applicable.
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A few different monitors:
JBL, not sure any more than that. Installed within the last year. these have the most noticeable hum, but they are also turned up the loudest.

photo 13 by afb127d79324c2d47dbd06b3c467317d, on Flickr

photo 23 by afb127d79324c2d47dbd06b3c467317d, on Flickr


44 by afb127d79324c2d47dbd06b3c467317d, on Flickr


photo444 by afb127d79324c2d47dbd06b3c467317d, on Flickr

from the floor pocket to the monitors

photo 24 by afb127d79324c2d47dbd06b3c467317d, on Flickr

from the board

photo 14 by afb127d79324c2d47dbd06b3c467317d, on Flickr

Jason Lavoie said:
That's a pretty key piece of info..
Two quick thoughts:
1: did the loaner board have different connectors and perhaps they used different cables (balanced?) to connect it to the EQ/Amps?
2: if you only have hum from the monitors, try swapping the main outputs with the monitor outputs and see if the hum moves to the mains or sticks with the monitors..

you probably have a wiring (signal wiring) issue.. if the board was the actual source of the hum it would probably be coming out of every output

Jason
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1- Yes everything was XLR out of the loaner. but we were only using 32 channels instead of our 40, so there were some wiring differences
2-I dont think i can switch the two, one is 1/4 and the mains are XLR
 
Re: Newb- Looking for some direction.

Jeff Sebers said:
1- Yes everything was XLR out of the loaner. but we were only using 32 channels instead of our 40, so there were some wiring differences
2-I dont think i can switch the two, one is 1/4 and the mains are XLR
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Again, great info.. what EXACTLY was left off the input list with the loaner mixer?

You could find an XLR-1/4" cable and at least try the mains plugged into Aux1, but I think my question above is more likely to lead us to the solution..

Jason
 
Re: Newb- Looking for some direction.

Jason Lavoie said:
Again, great info.. what EXACTLY was left off the input list with the loaner mixer?

You could find an XLR-1/4" cable and at least try the mains plugged into Aux1, but I think my question above is more likely to lead us to the solution..

Jason
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Sadly I was not in charge, so I don't know for sure.

I do know that all of our monitors were hooked up, along with the mains.
It was only a 16 channel board, so I know that some of the inputs could not have been hooked up.
 
Re: Newb- Looking for some direction.

Jeff Sebers said:
Sadly I was not in charge, so I don't know for sure.

I do know that all of our monitors were hooked up, along with the mains.
It was only a 16 channel board, so I know that some of the inputs could not have been hooked up.
Click to expand...

Ok, then the next step is to fire up the system so that you hear the hum..
unplug your inputs one at a time until the hum goes away. leave them unplugged as you go, because there may be more than one problem..
you'll either find a keyboard or other device that needs transformer isolation, or if you get to the end and there's still a hum, you'll have to check the connections to the monitor amps and your powered monitors.

Jason
 
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