microphone Help!...Audio setup issues whilst shooting

[Jo Barker]

Hallo all. I'm experiencing some interference problems with my audio setup whilst shooting. My set up is a RODE Video Mic Pro and RODELink receiver both connected via a Stereo Breakout 3.5 mm cable to my Nikon D750. I am experiencing some pretty bad interference to the Video Mic Pro from being near the RODELink receiver. I have them both set up on a triple cold shoe mount so that I can be a self shooting camera and sound unit, the RODE Video Mic Pro acting as my onboard mic for the Nikon.

I've tried multiple tests; putting them both into my Zoom H6 and the same thing happens; then tried swapping out the Video Mic Pro for a NTG2 and there is no interference from the RODELink receiver. I've also tried connecting the Video Mic Pro direct into my Nikon and the receiver to my zoom and the same interference happens when the receiver gets too physically close to the Video Mic Pro. I have tried changing channels on the RODELink receiver and still the interference continues. In short....after a longway round getting to this...I'm having problems with the Video Mic Pro as the RODELink receiver causes interference when too close to the Video Mic Pro.

Is this something anyone has experience before before?

Cheers!

Jo.x

 

[Alcove Audio]

First, welcome to IndieTalk.

Second, thank you very much for giving such a detailed explanation of the problem.

So far you have done all of the right things by trying alternate connective possibilities.

1 - You didn't mention whether or not you used the AC adapters at all while troubleshooting, so that may be one avenue to explore, that there may be a powering issue. Try fresh batteries all around, if you haven't done that already; it couldn't hurt. There is also the vague possibility of a grounding issue (the polarity is switched on one of the units), which in your case might be tough to track down.

2 - If you haven't already done so be absolutely sure that all of your cabling is proper - that the cables are in good shape & of good quality (cheap cables can let in RF & EM interference) and that they are the correct cables for the situation. The 3.5mm breakout cable is a possible suspect. You may need a splitter instead.

3 - However, everything you posted seems to be centered on the RODELink, so perhaps it is the RODELink itself which is the issue. I would have the unit checked out by a tech to be sure that it is functioning properly, or take it back to the place of purchase and try out a different unit, be it another RODELink or a different brand.

That's all I have for you for now.


Troubleshooting can be very, very frustrating at times. If you think your situation is bad try troubleshooting a recording studio, even a small project studio. Before digital audio became the norm every sound module and processor was external. When I set up my own studio back in 1987 I had five (or was it six?) sound modules in one rack, a dozen (if I remember correctly) processors (mic pres, compressors, reverbs, delays, etc.) and three keyboards in addition to a 24 channel mixing console and an eight track 1/2" analog tape machine, and the MIDI & tape machine had to be synched via SMPTE. All of them needed AC power, they all needed to have an audio connection to the mixing console which, for my studio, required five 48 point patch bays (480 points total - 240 points in, 240 points out), and all of the modules and processors needed to be connected to a MIDI patch bay. Lots of long cable runs, with audio, MIDI and electric crossing over each other; I tried to avoid crossover as much as possible, but a fair amount of crossover was inevitable. There was quite literally over a mile of cabling involved. So you can imagine how difficult it could be to track down a hum. So I feel for you.

Let us know if you resolved the issue and what the solution was.

Good luck!

Uncle Bob

 

[AcousticAl]

Troubleshooting can be very, very frustrating at times. If you think your situation is bad try troubleshooting a recording studio, even a small project studio.

Or, a full concert-level live sound system! Get a gremlin in one of those and it might be time to top off the coffee.

One thing of note: the Nikon D750 supplies plug-in power over the 3.5mm audio input. Thumbing through the user manual, there’s no indication that this can be turned off. It’s very possible that the magic combination of the RØDELink, VideoMic Pro, and Y-cable is allowing the plug-in power to cause issues.

If this is indeed the culprit, the solution may be to get an XLR breakout box with pre-amps made for DSLRs. These are built to defeat the plugin power voltage and keep individual sound sources isolated on input.

 

[Sweetie]

I'm having problems with the Video Mic Pro as the RODELink receiver causes interference when too close to the Video Mic Pro.

I haven't played with a Video Mic Pro before, but I do vaguely remember that they're not really shielded from RF signals.

Try testing to see if you continue to hear the noise with everything else off and only connected directly into the camera. If you find that fixes it, try moving the transmitter much further away from the microphone and see if that helps.

Uncle Bob

Welcome back.

 

[Alcove Audio]

Welcome back.

I never left.

 

[Alcove Audio]

Or, a full concert-level live sound system! Get a gremlin in one of those and it might be time to top off the coffee.

In some ways that's even worse, as you are time constricted - you've got to get it done before the audience arrives!

The most difficult part of troubleshooting a large sound support system is dealing with the promoter and the band managers and the prima donnas. Troubleshooting takes patience and concentration. If they would just shut up and leave you alone the issue would be resolved much faster.

 

[AcousticAl]

In some ways that's even worse, as you are time constricted - you've got to get it done before the audience arrives!

The most difficult part of troubleshooting a large sound support system is dealing with the promoter and the band managers and the prima donnas. Troubleshooting takes patience and concentration. If they would just shut up and leave you alone the issue would be resolved much faster.

100% truth.

Similar to the studio, digital systems have made things a little bit easier. The Cat5 snake eliminated many of the issues that analog snakes presented, but has introduced some new quirks. I mix a Christmas show every year here (well, except for this year) at our convention center. The first year we moved into the then-brand-new facility, I had buzzes and hums everywhere. Turns out the building’s power is filthy. The only solution was ground filtering (not lift, but filtering) on the AC for the amps.

But like any sound system, the key to trouble shooting is to start at the source and to chase it downstream until you find it. Start at the mic, and if that isn’t the issue then move to the cable, and so on down the signal chain until the problem is resolved.

 

[Jo Barker]

Hallo all. Thanks so much for all your comprehensive and intersting answers. I also went straight to the source and emailed RODE to see what they said and this was their pretty helpful reply:
"The Video Mic Pro uses an unbalanced cable to connect to most cameras, this type of connect is very susceptible to RF interference. The NTG2 has a balanced output that significantly reduces interference noise induced into the cable. The reason we use an unbalanced cable on this mic is because most camera don't have the option for balanced audio in.
I have not come across this issue before in a previous service request. To me it sounds like the issue of an unbalanced cable interference (mention above). The solution here may be distance the RX unit fro the VideoMic Pro. You can try clipping it to your belt and having a longer TRS cable run to your camera."
That said it doesn't really help my predicament as it is an essential part of the setup to have both the onboard and lav receiver mounted on top of the camera, so they can feed in and be synced to the footage ready for post. So I've asked if they have any smaller mics like the Video Mic Pro that are balanced. Or like you said @AcousticAl an XLR breakout box would be the way to go.

Cheers!x