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Author Topic: Static Pop  (Read 3647 times)

Duane Sanders

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Re: Static Pop
« Reply #10 on: February 10, 2017, 01:28:03 pm »

Looking from the perspective of equipment rack/cabinet:

Is there more than one equipment rack (i.e. a rack for audio, a second rack for video/streaming equipment)?
Are the cables brought into the equipment rack(s) through metal conduits or cable tray?

Some installers do not put bonding wires between multiple racks, some do not bond a cable tray to the rack.  Even with EMT conduit, the far end of the conduit may just be hanging in the plenum space.
So it is possible that with the additional ground, you have different ground potential if not everything is bonded together.

This could be as simple as bonding multiple cabinets together or putting "sensitive" equipment on a UPS or isolation transformer, or more involved solutions requiring a balanced power system.

John R.

Ok John.  great questions.
Since taking over this area i have been planning some changes.

There is one rack that holds Furman power Controller and a Furman Power Conditioner.
Most wireless mics are in the power conditioner.  i plan to purchase another one for the rest of the wireless mics.

Behringer X32 is plugged into the Power Controller.  I am planning on putting it into the second Power Conditioner.

At this point there is no conduit in the sound booth.  All cables and wires are laying on the workbench behind the equipment.  Oh My!  That will change as soon as i order some cable trays.  The monster cable starts at the mixer and is exposed for about 10 feet before it goes into the PVC conduit going to the stage, which is about 80 feet.

Many things are plugged into powerstrips on the workbench with minimal surge protection.  I plan also to get 1 or 2 UPS/surge protectors to replace these.

Video/streaming is a very simple Wirecast on a PC with Lexicon Omega for sound.  Presentation is ProPresenter on iMac. they are all in powerstrips.

Everything works beautifully.  Just need some housekeeping and to get rid of this static pop.  and have some protection for all this expensive equipment.

thanks for the ideas.
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Duane Sanders

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Re: Static Pop
« Reply #11 on: February 10, 2017, 01:53:18 pm »

Are you using an S16/32, or DL16/32 digital snake box?  If so.... is your CAT5e cable shielded and terminated with Ethercon® connectors that bond to the RJ45 ground?

we are not using any stage boxes

thanks
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Duane Sanders

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Re: Static Pop
« Reply #12 on: February 10, 2017, 01:56:36 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.

Hey Dick.
love the avatar.
i am not sure if the rack & mixer have individually been grounded.
i will check that.
great idea.
thanks
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Mike Sokol

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Re: Static Pop
« Reply #13 on: February 11, 2017, 08:36:49 am »

Are you using an S16/32, or DL16/32 digital snake box?  If so.... is your CAT5e cable shielded and terminated with Ethercon® connectors that bond to the RJ45 ground?

Yes, without a shielded CAT5e snake the Behringer X32 stage box can mute the entire audio with a static discharge on a single mic. Apparently the AES50 protocol uses a separate signal pair for clock, and without a shield it's possible to interrupt the clock. There's a cool video on this effect somewhere showing how easy it is to make this happen with UTP.

Keith Broughton

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Re: Static Pop
« Reply #14 on: February 11, 2017, 09:28:12 am »

Yes, without a shielded CAT5e snake the Behringer X32 stage box can mute the entire audio with a static discharge on a single mic. Apparently the AES50 protocol uses a separate signal pair for clock, and without a shield it's possible to interrupt the clock. There's a cool video on this effect somewhere showing how easy it is to make this happen with UTP.
A similar problem was duplicated on a Pro 2 using UTP.
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Dan Mortensen

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Re: Static Pop
« Reply #15 on: February 13, 2017, 03:48:39 am »

Ok John.  great questions.
Since taking over this area i have been planning some changes.

There is one rack that holds Furman power Controller and a Furman Power Conditioner.
Most wireless mics are in the power conditioner.  i plan to purchase another one for the rest of the wireless mics.

Behringer X32 is plugged into the Power Controller.  I am planning on putting it into the second Power Conditioner.

At this point there is no conduit in the sound booth.  All cables and wires are laying on the workbench behind the equipment.  Oh My!  That will change as soon as i order some cable trays.  The monster cable starts at the mixer and is exposed for about 10 feet before it goes into the PVC conduit going to the stage, which is about 80 feet.

Many things are plugged into powerstrips on the workbench with minimal surge protection.  I plan also to get 1 or 2 UPS/surge protectors to replace these.

Video/streaming is a very simple Wirecast on a PC with Lexicon Omega for sound.  Presentation is ProPresenter on iMac. they are all in powerstrips.

Everything works beautifully.  Just need some housekeeping and to get rid of this static pop.  and have some protection for all this expensive equipment.

thanks for the ideas.

Duane, you said that you are not using any stage box. How is the signal getting to the console from the stage/altar area? Mic cables? Analog snake?

Are you quite sure that it isn't the operator touching the console when everyone stands up and sparking it with a finger?

Do the mic cables from the stage run below or through that area where the seats were?

You said in the OP that the chairs in that area actually touch the sound booth wall; what is that wall made of, and are there any nails or something similar which when zapped from the chair side run through the wall and touch any metal that touches the mixing console? (You said there was no conduit in the booth.)

Those questions all relate to the part I don't understand: If the collected group of people are collecting a static charge, that should make no difference to the PA until it discharges into the PA or its power. How does that discharge occur? If it jumps through the wall and into the console, that is one thing. If it jumps through the floor into the cables connected to the console, that is another thing. If it's still happening after the seats are removed, that's something else. And how is there a group static discharge from multiple people together so it's worse than from one person?

Did removing the chairs from that area solve the problem or is it still happening? You don't quite say that in your posts.

Is the AC electricity fully using twisted pair plus ground cables? And there is a good connection between X32 ground and earth ground? Asking Jonathan's question a little differently, what is the path to ground from console to ground rod or whatever?

As a separate issue which you don't seem to be having but could: if the console wall power is disrupted or drops below something like 85 volts for more than 2 cycles of the 60Hz sine wave, it will reboot. Meaning no audio till it gets back online.

That can be prevented with a cheap UPS, like $40. You can also solve it with a $1000 true sine wave UPS, but the cheap ones seem to work just fine, too. I use a Cyberpower 350 watt one from Amazon https://smile.amazon.com/gp/product/B004OR0V2C/ref=oh_aui_search_detailpage?ie=UTF8&psc=1  I've read that they are somehow hard on power supplies while simultaneously reading that switching power supplies don't care if the AC wave is sinusoidal or not. I know for a fact that the console doesn't seem to suffer when you yank the power cord to the UPS. I'm not sure which Power Conditioner you use but I don't think those things will take losing power completely for any length of time while keeping the console running.

I'm one of the people who has used a BBQ sparker to test static disruption to X32 signal, and I don't recall checking the ground of the naked (no S16/32 stage box/CAT cable combo) console. This is a very very busy week and I don't think I'll have time to set up a console and try it but maybe Brian Wynn, who discovered the solution to the problem, will read this and have some time.

Good luck, this is an interesting problem.
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Tim McCulloch

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Re: Static Pop
« Reply #16 on: February 13, 2017, 04:14:03 am »

I'm one of the people who has used a BBQ sparker to test static disruption to X32 signal, and I don't recall checking the ground of the naked (no S16/32 stage box/CAT cable combo) console. This is a very very busy week and I don't think I'll have time to set up a console and try it but maybe Brian Wynn, who discovered the solution to the problem, will read this and have some time.

Good luck, this is an interesting problem.

Brian hasn't posted since May of 2015, his last log in was Christmas Eve 2016.
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John Rutirasiri

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Re: Static Pop
« Reply #17 on: February 13, 2017, 10:48:18 am »

Many things are plugged into powerstrips on the workbench with minimal surge protection.  I plan also to get 1 or 2 UPS/surge protectors to replace these.

I'm one of those that believe a power-strip style surge protector is useless.  Most of the time it's a couple MOVs that no longer shunts current after taking a couple of hits.  You're better off with a UPS or true voltage regulator than a power-strip surge protector.

On a different note, this weekend I got a call from a church where they were experience not static pops, but random loss of audio for 3-4 seconds at a time.  They had new a couple of 20A circuits put in that wasn't shared with any other appliances.  Licensed electrician did a good job, and measurements confirmed there was no brownout during these loss of audio. 

It turned out that a couple of light switches in the church were so old and worn out, they were arcing when flipped.  When this happened, there was enough electrical noise generated to cause the speaker processor to lose sync on its AES/EBU input.  When that happens, the speaker processor mutes the sound, and will only unmute after regaining sync. 

None of the sound equipment is on a UPS or isolation transformer...
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Jonathan Johnson

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Re: Static Pop
« Reply #18 on: February 13, 2017, 01:26:22 pm »

That can be prevented with a cheap UPS, like $40. You can also solve it with a $1000 true sine wave UPS, but the cheap ones seem to work just fine, too. I use a Cyberpower 350 watt one...

One thing to be aware of with these cheap UPSs: only some of the receptacles on them are backed up by battery; the others only have surge protection. I can't tell you how many times -- it's a lot -- that I've found these under peoples' desks with the PC connected to the "surge only" side and the laser printer and desk fan connected to the "battery backup" side. People just don't know what those words next to the outlets mean.

I suspect (though I haven't disassembled one to see) that the surge protection provided by these UPSs is no better than a standard MOV surge strip. There is no voltage regulation going on; the unit switches to battery when the voltage goes below some threshold. Not sure it switches to battery in an overvoltage condition -- some might.
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Dan Mortensen

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Re: Static Pop
« Reply #19 on: February 13, 2017, 04:20:34 pm »

One thing to be aware of with these cheap UPSs: only some of the receptacles on them are backed up by battery; the others only have surge protection. I can't tell you how many times -- it's a lot -- that I've found these under peoples' desks with the PC connected to the "surge only" side and the laser printer and desk fan connected to the "battery backup" side. People just don't know what those words next to the outlets mean.

I suspect (though I haven't disassembled one to see) that the surge protection provided by these UPSs is no better than a standard MOV surge strip. There is no voltage regulation going on; the unit switches to battery when the voltage goes below some threshold. Not sure it switches to battery in an overvoltage condition -- some might.

Definitely agree.

In this one's case, the side identifiers are molded into the plastic in black-on-black letters so it's hard to see. I tape over the Surge side because that's not what I bought them for. The battery side seems to work fine, although mounting in a rack requires some creativity and there are only 3 battery-side outlets.
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