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Author Topic: Static Pop  (Read 3795 times)

Duane Sanders

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Re: Static Pop
« Reply #30 on: March 14, 2017, 07:35:16 pm »

Static Guard is good.  I've tamed several church systems with "winter-pop" by simply putting drain wires from any rack rails and the mixer chassis to a proven ground.

We have created a mixture of dryer sheets and  water in a pump sprayer.  We also have drain wires embedded into the carpet in the seating area.  the rack does not have a separate drain wire that i remember....i will check again and install one if its not there.  I have talked to a few people about attaching a ground wire to the mixer, but they have all said that the mixer has internal grounding wires attached to the chassis internally.  So we are unsure what attaching another one externally would do.
thanks for the ideas.
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Duane Sanders

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Re: Static Pop
« Reply #31 on: March 14, 2017, 07:52:36 pm »

Hi Duane,

Thanks for the reply and more info.

You say "all the cables". They are all individual mic cables? Could there be insulation worn off on one of them so that the metal riser is contacting the shield of a cable?

Are they all one run or are they multiple cables connected end to end? If the latter, could one or more of them have pin 1 shorted to the connector body and the body touching the metal riser?

There's a couple possibilities for you to look for.

Dan

Hey Dan,
thanks for the info.  We only have two wired mics and they are not used very much.  But they are in great condition.  There is no correlation to the static pops. We were not even using them the last time the static pop occured.

duane
 
« Last Edit: March 14, 2017, 07:59:03 pm by Duane Sanders »
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Duane Sanders

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Re: Static Pop
« Reply #32 on: March 14, 2017, 07:57:29 pm »

Guess this guy bailed. Nearly a month since he posted.

Too bad, it was an interesting problem and I was hoping to learn how the static was entering the system.

Dan,
LOL!  I havent bailed.  I have actually been overwhelmed with my day job and family.  I have a great team helping me and we will find the issue in time.  i appreciate the time and effort all you guys have put into helping me figure this out.  all have had really great info and ideas.
keep them coming.
we will figure this out.  I will check in with the forum when i can.  if you need to contact me i am available by email. please do so.
:)

Duane
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Duane Sanders

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Re: Static Pop
« Reply #33 on: March 14, 2017, 08:12:34 pm »

You really need two pieces of information to troubleshoot these kind of problems.

1) Under what circumstances is it repeatable? Does it only happen periodically when a light switch is flipped on? Or when a cash register door is opened? Or when someone scuffs their feet on a rug and touches the pulpit mic for the first time? That's the trigger causing the problem.

2) How does the problem manifest itself? Is it a signal dropout? Is it a pop? Is it a buzz? Is it a hum? Is it a level change? That can hint as to where the problem is coming from.

Once you identify the above two things, then you can start speculating as to what's actually happening. I always try to divide and conquer. Shut off all the RF mic receivers to make sure it's not from some RF hit. Turn off the console and see if you can force the problem with just the amplifiers powered up, etc...

Mike,
the only time this static pop occures is when the people stand for prayer.  no light switch is touched.  no one is moving around on the stage.  sound booth people are hands off.  we are already standing so we dont think it is us. 
It is a definite pop.  not a hum or buzz.
my next trials will include turning all the wireless mics off and unplugging the transmitters and trying to replicate the issue.
it may take me a month to do that, but i will report back...

duane
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Mike Sokol

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Re: Static Pop
« Reply #34 on: March 14, 2017, 09:30:59 pm »

Duane,

You noted in a PM to me that you didn't have time to check in to see if anyone had posted more info. If you notice at the bottom of your posting area there's a "Notify" button. If you switch that on the BBS software will send you an email anytime there's a new posting on this particular thread. So you don't have to bother to check in, the board will email you automatically.

Jonathan Johnson

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Re: Static Pop
« Reply #35 on: March 15, 2017, 01:41:19 am »

the only time this static pop occures is when the people stand for prayer.  no light switch is touched.  no one is moving around on the stage.  sound booth people are hands off.  we are already standing so we dont think it is us. 
It is a definite pop.  not a hum or buzz.
my next trials will include turning all the wireless mics off and unplugging the transmitters and trying to replicate the issue.

In a sister church (same denomination as mine, different congregation), they had a gooseneck condenser mic on the pulpit. If the mic was bumped or the speaker had a strong plosive, a loud pop (no unlike a "static pop") could be heard. It turned out to be a poor connection in the base of the microphone; tightening some screws resolved the issue.

Perhaps someone on stage has a handheld mic with a similar issue, and when everyone stands for worship, they also move the mic a certain way that causes an internal connection to move. That the folks right in front of the sound booth stand up simultaneous with the pop may simply be a coincidence.

(Kind of a long shot, but I figured I'd throw it out there.)
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Stop confusing the issue with facts and logic!

Dan Mortensen

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Re: Static Pop
« Reply #36 on: March 15, 2017, 03:09:31 am »

Dan,
LOL!  I havent bailed.

Good! I'm happy to read this, and think about your problem periodically and wonder what the solution could be. Jonathan's idea of a completely unrelated thing happening always at the same time is good out-of-the-box thinking and you have to do it, too. Mike's suggestion about leaving everything on and wrestling with connected gear is good, too. This includes shaking the console and all interconnection wires.

You have to figure it out and tell us about it. You can be famous for identifying and fixing a problem.

Again, good luck.

PS In your reply to my question about mic cables, you only address mic cables used as mic cables and not as drive signal cables from the console to the stage, which is what I was thinking when I wrote it. You have to check those drive lines, too, not just microphone cables.

Where are the wireless mic receivers located? If distant from the console how do the signals get to the console? Where are the antennae located? Again, if distant from the receivers, how do the signals get to the receivers?  All those interconnect cables are potential problem sources if insulation is worn away or if connectors are miswired (pin 1 shorted to connector body either accidentally or intentionally by the builder) and something that channels the static electricity is touching the problem area of a wire. The zap could be happening in the console (if it's malfunctioning) or in a wireless receiver. Since we have the same consoles I want your problem to be somewhere else.
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Mike Sokol

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Re: Static Pop
« Reply #37 on: March 15, 2017, 10:56:37 am »

So here's another thing to consider. I did a gig at a Synagogue last year and during setup seemed to have an RF mic from another room coming through my portable sound system. I looked at my 6 channels of RF receivers and couldn't see it hitting them, but I turned them off anyways. Within minutes the other room's beltpack transmitters came though at full volume. So I shut off the console and waited. Sure enough in a few minutes the other beltpack's mic banged through again. Impossible, I thought. I went around and pulled the power for every one of my active speakers. You guessed it, within minutes the voice beamed through again. Of course the Rabbi was in the room while this was happening and wondering why I didn't know what I was doing. I told him what I was hearing was impossible technically, but I would figure it out. That's when I discovered their original house sound system in the closet which was turned on and had RF tuned to the transmitters in the other room. And it was turned up full blast through all the ceiling speakers throughout my room. They had turned on that rack without me knowing in order to power up their Assisted Hearing System. And since I was in the back of the room I couldn't localize exactly which speaker the sound was coming from. It seemed to be coming from everywhere, which was exactly right since they had a few dozen ceiling speakers in my room alone.

So the lesson is.... Sometimes you have NO idea what you're really hearing. The first step is to assume that everything you know is wrong, and try figure out what's really making the noise. Here's an old Firesign Theater album that says it all:  https://www.youtube.com/watch?v=YKZtt2yEwfs
« Last Edit: March 17, 2017, 08:25:09 am by Mike Sokol »
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Jean-Pierre Coetzee

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Re: Static Pop
« Reply #38 on: March 17, 2017, 07:47:19 am »

If this pop is really loud you should be able to see it on the mixer output meters... If the meters jump when the pop occurs then you can start to narrow down where the pop is coming from.

If there is no movement on the mixers output meters then look after the mixer in the signal path. You have tools at your disposal, it would be best to use them to attempt to narrow down the amount of time you need to spend faultfinding this problem. The fact that it is easily reproduced makes it easier to find as well.

Ask some people if they would like to help solve the problem and have them come and stand up and sit down sometime when there isn't a church service on, this doesn't have to be during your usual 9-5 since TBH they probably aren't available then either. You want to know exactly where the problem is coming from. It would be a good idea to start with the sound system off just in-case it isn't part of the sound system at all...

On an unrelated not I had an intermittent tripping fault that was actually caused by a broken cable insulation somewhere in the roof. Took forever for the insulation to be damaged enough for us to narrow down the problem and thankfully without some sort of fire but then again that is more likely thanks to our decent electrical code than due to luck...

Sometimes physically looking at every single cable from top to bottom is what is required.

Similarly the 48 channel snake in our main auditorium died one day before our mid week rehearsal, we only found that when they had replaced one of the chairs in the venue(all bolted down soft seaters) that they had put a bolt right through the snake, we knew the problem was damage to the outer core of the snake because we could correspond the non-working channels to wires running nearer the outside of the snake but didn't know exactly what caused it.

Fualtfinding is all about following the signal chain. Find out if the problem is before the mixer or after the mixer and then start at one point of the signal chain and move towards the other until the problem is discovered. If you have found the problem and cannot figure out how to solve it come back here and we will be very helpful, post any progress as well, we love problem solving.
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Word & Life Church

"If you want "loud", then run a piece of sheet metal through a table saw------

If you want "watts"-then plug in a toaster"
- Ivan Beaver

Mike Sokol

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Re: Static Pop
« Reply #39 on: March 17, 2017, 08:49:15 am »

Here's another one... I once was troubleshooting an intermittent hum in a church and finally narrowed it down to the amp rack. That is, if I slammed my hand on the top of the rack I could make the hum come or go. So I started tapping on wires one at a time and found that the one XLR cable feeding a power amp was the culprit. Any movement of the cable could make the hum start or stop. So I took the XLR connector apart to see the cause. This was an old Switchcraft XLR that needed the little clear insulator inside to keep the wires from making contact with the shell. Some previous technician had cut the pin-1 wire (shield) to stop a rather nasty ground loop hum caused by the building wiring. But he left the wire dangling inside of the XLR connector. It was also missing the insulator sleeve so the twisted bare wire was now laying inside of the shell. Any vibration or movement of the cable was enough to make contact, so the ground loop hum would come and go apparently at random. I simply cut the bare shield wire back, put a wrap of e-tape around the soldered connections, and reassembled the XLR connector. Problem solved... 

This probably took me an hour to find and fix, but it was well worth the time. The church had been having this random hum problem for several years.
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