Since we can't hear what it sounds like, cell phones/Blackberries "calling home" can be an audio issue.

Mike

Sorry guys. This is the first time I signed up for Mediafire and I linked incorrectly.

The link is fixed now and the .wav sample can be opened or downloaded if you wouldn't mind listening to it to tell me if you recognize the noise.

Thanks

John

Cell phone too close to mic or soundboard. I hear that all of the time in my edit room either with my phone or a clients phone.

My phone also interferes with my wireless mouse that I use with my laptop.

You need to have all crew or anyone close to mics or soundboards turn off their phone.

Dave T2

(Ooops - DaveT2 posted while I was still typing...)

I'm almost certain its a cellphone (or similar device).

In fact, as I was playing your wav file and heard the beeps I instinctively reached into my pocket and pulled out my cellphone to set it further away behind me because I thought it was my phone making the beeps as I was listening to your file. I had to pause then play then pause your file to convince myself the beeps were recorded in your file and not going on "real time".

It must be the differences in carriers and the specific type of phone service, because not everyone's phones do this, but mine (all four phones in my family) make these beeps periodically all day long, picked up by and played through any nearby PC speakers or Television (but only if they are turned on). All of the PC's and TV's are kind of old though, so I don't know if its a frequency that newer equipment would be designed to filter out.

It happens periodically if the phone is on (but not in use) as the phone contacts or replies to the mobile service every so often. I can usually hear the beeps like that over my PC speakers just before the phone rings or receives a text. (And all of this is VERY annoying...)

I know I can pick up these beeps through my Rode VideoMic, so I always turn the phone completely off when using it. I'm not sure why you only picked it up in the left channel, but I guess that was fortunate.

Agree with Dave, this is classic mobile phone breakthrough.

Depending on distance from nearest base station mobile phones can be transmitting watts of power. They send a "I'm here" heartbeat every so often even though they're not in use. EVERYONE in the auditorium should have their phones OFF, "silent" mode makes no difference BTW, been caught out by this once.

Better kit that uses transformer inputs and outputs does seem more immune to this problem, better XLR leads with serious shielding helps too. Problem today is we're being swamped with radio signals and although mobile phones are the worst offenders you can find a lot of RF based gear in use in theatres.

Bob.

Certainly sounds like RF interference from a wireless digital device, could have been a cell phone or a network router.

The fact that it's only on the left channel suggests that the shielding on a cable may have been bad. Were you running a "real" balanced line between the mixer and the camera? (Some mixers don't provide a truly balanced line output.) It could have also been some piece of unbalanced audio equipment plugged into the mixer. Regardless, you can zoom into the waveform and clearly see that it's some sort of digital pulse interference, most likely RF-induced from a cell phone.

Thanks guys. I guess it's unanimous. Blasted cell phones. Worst invention in my lifetime.

I don't know why it was only on the left channel or who had the cell phone. My setup hasn't changed in years and I recorded four shows without that sound being recorded except for that one night.

I ran the main XLR cable from the stage under the auditorium and up through the sound board console, then over to my camera as I always do. I guess as John and Bob both suggested, truly balanced wiring may have avoided this interference.

Yet the cell phone couldn't have been near the stage mics unless one of the actors (high school) had it on them and turned on while near one of the mics located stage right.

Or of one of the sound board people (who are truly incompetent high school students) had one turned on.

Or maybe someone right near the camera?

Since I reluctantly only occasionally use a Pre-Paid TracFone, that obviously well known cell phone noise totally escaped me as to what it was.

Thanks for letting me know. Hopefully it will never happen again and if it does, hopefully it will only be on one channel like this time. It was sure easy to get rid of thank goodness.

Thanks again.

John

I've also had other electronics introduce noise directly into my camera. One was an organ during a wedding. My second camera was in the balcony and each time the organ was turned on, it put a dull thumping sound onto the tape. That sound did not come in thru the mike.
Another was a photographers electronic flash. Each flash (when the photog was 10 feet or less from me) caused a beep in the sound and again, it didn't come in thru the mike. I only had a wireless receiver on the cam at the time and the mike was 50 ft away.

Lynn

We have an oncamera light that'd inject a very high frequency noise into the audio circuits of cameras if the light was powered from the camera. It took a significant LC pi filter in the supply to the light to tame the problem. Apart from one client I was the only person who could hear this noise, I'm still good to 18KHz thankfully.

Bob.

. . . waking up . . . Yup, that'll be a CellPhone.

Gonna have a go with IzoRX - just for larfs!

Grazie

Yup .. . Izotope RX did it. Didn't even blink . . Smooth sound and I can't hear hidden artifacts.

If you can "See" the noise you can zap it. I used IzotopeRX "Declicker" - done! Used the "Digital Clicks (more severe); Sensitivity 8.3; Quality Medium; Maximum Click width [ms] 2.0. I got to this by looping the sound and adjusted in real time. - I love this s/w!

Grazie

I love Izotope RX, too. I just got rid of some pretty obnoxious air conditioner noise that had the producer all freaked on location. He was absolutely certain that we'd have to do ADR on the scene and he just didn't have the budget or the time for that. I told him to calm down because I had a "trick", Izotope produced a pristine audio track completely devoid of that pesky air conditioner. I'm sure as heck not going to tell him what the trick is, he just thinks that a miracle has occurred.

I'm another Izotope RX fan.

I've been spending time removing bird chirps from behind interviews so that they don't sound incongruous when the director uses the interviews as overlay where ' happy chirping birds' aren't appropriate. Also completely removed squealing motorbike brakes (offscreen) from behind an interview with the Spectral Repair tool.

I also have a particular fondness for Waves Z-Noise for general broadband clean ups.

I wish Vegas would allow you to select multiple events and do a non-realtime render across them though as ProTools does... maybe in some future version???

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