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[joel florendo]

At my church we are using a Behringer X32C for our broadcast. It is connected to our main soundboard in our auditorium (Behinger X32) with an ethercon cable. Everything is working generally except intermittently we get this garble noise. It happens randomly and without any warning. It eventually goes away (we always turn the main fader down and just wait it out). Here is a sample of the noise:
https://youtu.be/FpAOx-XdnBE?t=5180

I've tested out the ethercon cable with a tester and everything (including the ground) check out. I've looked at the channels when it happens and it's not coming from any of them. (The sample I linked to is actually when all the channels except for our post service music are muted).

Anyone have any idea where this is coming from and how to make it stop?

[Dave Pluke]

Anyone have any idea where this is coming from and how to make it stop?

What sort of wireless gear is in use?

I've heard sort of similar noises resulting from interference between cell phones and wireless devices (hearing assist, body packs, etc.).

Dave

P.S.  No chance somebody is mixing daiquiris with a blender plugged into the same circuit, is there  ?

[Kevin Maxwell]

It sounds like an iPhone is too close to either the mixer or an unbalanced source like a wireless body-pack in someones pocket that also has an iPhone on them.

[Scott Holtzman]

I've tested out the ethercon cable with a tester and everything (including the ground) check out. I've looked at the channels when it happens and it's not coming from any of them. (The sample I linked to is actually when all the channels except for our post service music are muted).

Anyone have any idea where this is coming from and how to make it stop?

Joel a simple continuity tester tells you nothing about the performance of Ethernet cable.


People tend to think of twisted pair cable in electrical terms however network speeds of 100Mpbs (100Mhz) or 1 Gigabit (1 Gigahertz) are more akin to coaxial cable than electrical cable.  It is basically a transmission line.  Special testers will perform RF, crosstalk and other important stress tests on your structured wiring system.


You noted that the connection of the ground between the two mixers is good, that is important with the Behringer/Midas implementation of AES50.  Testing the actual data capacity though is equally important.  Lastly keep in mind that the AES50 spec does not use the same pinout as Ethernet.


That does not sound like anything occurring in  the digital domain (other than the actual modulation of the induced signal).  Since AES50 multiplexes multiple channels you would get widespread interference, not a specific timeslot.  That signal is getting in before the A to D converter in the preamplifier.

[Mike Caldwell]

Do some test with no audio playing and all wireless equipment turned off.

Do you have a router or access point near any of the mixers or other audio equipment.

You may want to check your mix, the vocals all seem panned heavy to the right channel.

[joel florendo]

What sort of wireless gear is in use?
I've heard sort of similar noises resulting from interference between cell phones and wireless devices (hearing assist, body packs, etc.).

It sounds like an iPhone is too close to either the mixer or an unbalanced source like a wireless body-pack in someones pocket that also has an iPhone on them.

Do some test with no audio playing and all wireless equipment turned off.

Do you have a router or access point near any of the mixers or other audio equipment.

Hmm...yes most likely the person mixing the broadcast has a phone on them. The only other input in this board is an iPod that plays our pre/post service music. As for wireless devices, we have wifi throughout the building but the network gear is far from the board. We have wireless IEMs and mics that are in our auditorium which is a different room separated from our broadcast board by multiple walls. Not sure if those still could cause an issue...?

I will try that test as well as test out having the tech shut their phones off during service. Thanks for the replies!

[joel florendo]

People tend to think of twisted pair cable in electrical terms however network speeds of 100Mpbs (100Mhz) or 1 Gigabit (1 Gigahertz) are more akin to coaxial cable than electrical cable.  It is basically a transmission line.  Special testers will perform RF, crosstalk and other important stress tests on your structured wiring system.

Scott, can you recommend a tester for these things?

[Scott Holtzman]

Scott, can you recommend a tester for these things?

Fluke Lanmeter is great but it is $5000 and up.  Why not just purchase the right cable?

[Kevin Maxwell]

Scott, can you recommend a tester for these things?

To Joel, the original poster in this thread.

The proper EtherCon configured cable is very important but let me make clear that this noise that you have experienced is probably not anything to do with the EtherCon cabling. It is as has been said most likely an iPhone device near something that is an unbalanced input into the X32 or X32C. The solution is to not have that iPhone near anything that it will interfere with.

The following is what I was told about this years ago when this noise would show up on a sound system. This noise is usually coming from what is sometimes referred to as the handshake signal from the iPhone. It doesn’t even need to be in use making a call or texting, it is something that it does to acknowledge itself to the cell system. The cell system is saying where are you and the phone is saying I am here. It is a signal that is much more powerful than the signal is when one is making a call or receiving or sending text. But it might even be when making a call or texting. And sometimes it is when an iPhone is even on silent more or vibrate mode and a call or text comes in. I have had clients send me a recording of this interference and it turned out that the person preaching had an iPhone that was on in their pocket. 

[Ed Taylor]

To Joel, the original poster in this thread.

The proper EtherCon configured cable is very important but let me make clear that this noise that you have experienced is probably not anything to do with the EtherCon cabling. It is as has been said most likely an iPhone device near something that is an unbalanced input into the X32 or X32C. The solution is to not have that iPhone near anything that it will interfere with.

The following is what I was told about this years ago when this noise would show up on a sound system. This noise is usually coming from what is sometimes referred to as the handshake signal from the iPhone. It doesn’t even need to be in use making a call or texting, it is something that it does to acknowledge itself to the cell system. The cell system is saying where are you and the phone is saying I am here. It is a signal that is much more powerful than the signal is when one is making a call or receiving or sending text. But it might even be when making a call or texting. And sometimes it is when an iPhone is even on silent more or vibrate mode and a call or text comes in. I have had clients send me a recording of this interference and it turned out that the person preaching had an iPhone that was on in their pocket.

nice reply Kevin.
and yes, I was going to even suggest that the FOH guy watch his channels close..it could be a phone on one of the players on stage.. I've made the mistake of placing my iphone on top of my bass amp..talk about an antenna !!
also, not sure the original post mentioned how loud the noise is...can you gate for that, or is it as strong as the main audio signal?

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