Wireless Huh? Distortion?

[AudJ]

Hey, about to troubleshoot this, and don’t know where to begin. This has never happened before:

Outside groups wants to use 10 channels of our 20 channel system. But do not pay me to come in to run sound. I set it up for them on Friday- all channels good. Saturday they did a sound check with their guy - all good. Sunday they turn it on for the performance, and find 9 channels are producing “distortion”. The 10th channel was not tested, they aborted and used no sound system.

I talked them through the effects section of the board, and all were disabled as I left I left it.

I assume intermod, and can’t do anything over the phone, so I have to figure it out Monday. But I can’t figure how a single source of interference could cause 9 mics to go down. I also don’t know how far they went before saying all of the channels were making the noise. It is possible they had the problem on a channel or 2, and aborted. Also possible some sort of user error as I might uncover Monday.

Mics used were half in the 500’s, and half in the 600’s (yes we are replacing those).

Any leads I can start with that might cause a failure across 9 receivers all of which have worked fine for over 8 years?

 

[AudJ]

Oh, and batteries were all new Friday, and replaced when the noise occurred, so I don’t think that had anything to do with it.

 

[EdSavoie]

Without knowing the knowledge level of the user, my first thought would be a signal running too hot, either they pumped the gain on every channel to make it "louder" instead of adjusting the output levels or amp levels, and were thus clipping the signal?

 

[TimMc]

The description of the noise makes it difficult to assess. So from the way you set up the system (and I presume this is in "your" venue with house mixer and PA), what was changed when you got back to it? Anything RF? Console input strip changes like gain, EQ? Output levels hotter?

So many potential places to look and there will probably be more than 1...

Back in Ye Olde Analogue Dayz some punter would stop by the console and ask "which one of those is the 'suck' knob?" My usual reply was "they all are, if you use them wrong."

 

[Amiers]

I’d say user error. Tell them next time they should pay for th tech that knows the gear.

 

[TimMc]

I’d say user error. Tell them next time they should pay for th tech that knows the gear.

That's ultimately where I was heading.

 

[AudJ]

Thanks for all the thoughts, i will look at all of those things, and appreciate a list to go from! -thank you!
It seems like it boils down like I thought, either they did something weird at the board (which I’m hoping to find evidence of), or there is some anomaly that came and went, and we’ll never know unless it happens again.

This is complicated by the fact the my boss’ son is in the group, so they called me by looking up my personnel records... during church on Sunday...also calling my emergency contacts when I didn’t respond right away... so “not my fault” would be a great thing here, but so hard to prove. When I did get back to them, there was not a lot of time, and they only wanted to locate a big red “easy” button, so information to diagnose was not forthcoming.

Hopefully they will realize the importance of hiring the guy with experience and knowledge of the system.

 

[AudJ]

The description of the noise makes it difficult to assess. So from the way you set up the system (and I presume this is in "your" venue with house mixer and PA), what was changed when you got back to it? Anything RF? Console input strip changes like gain, EQ? Output levels hotter?

So many potential places to look and there will probably be more than 1...

Back in Ye Olde Analogue Dayz some punter would stop by the console and ask "which one of those is the 'suck' knob?" My usual reply was "they all are, if you use them wrong."

Yes, all my house system, I preset everything, including the wireless frequencies myself. I’m going in tomorrow am to look at everything, but since it is a digital board, it will likely be set exactly as I left it, unless someone decided to save.

 

[AudJ]

Hehe - the result is not nearly as interesting as I thought it might be. The equipment they were plugging into the pack (Guitars) was running a lot hotter than out test equipment. Needed to bump down the squelch. If only I was present to hear what they were talking about, could have nailed that in within seconds...

Thanks for the ideas!

 

[Amiers]

Hopefully you just sold them that they need the proper techs to do the job if they don’t want to look like a bunch of fools.

 

[JD]

Hehe - the result is not nearly as interesting as I thought it might be. The equipment they were plugging into the pack (Guitars) was running a lot hotter than out test equipment. Needed to bump down the squelch. If only I was present to hear what they were talking about, could have nailed that in within seconds...

Thanks for the ideas!

Was going to suggest an input gain problem (padding) as sometimes what doesn't clip one day does the next when everyone gets a bit louder!