RODE NTG-2 Audio Glitch

[Brian Reynolds]

Yep it’s a 180 deg phase error.
In mono the VO is canceled the next question is how and where did the error occur?
Did you record it as just a single track or some other way.

[Antony Bui]

Sorry, but could you explain what a 180 deg phase error is? I think I recorded it just as a single track, yes. It’s just the default settings on the H4N. I can check it out in the morning and give you more details.

Thank you so much for the quick reply-especially on today. Merry Christmas!

[Brian Reynolds]

Let me explain it simply for you… an audio signal is an AC voltage microphones generate a very small voltage. (line level is much higher)
OK when you record audio it is normally a positive direction on the track and if by chance a second track is recorded incorrectly it may be in a negative direction (a mirror image of the other) and if those 2 tracks are added together at some point later they equal out to zero or a mute output in mono. (and this is what has happened in your case)

So how did this happen? Most likely an incorrectly wired connecting cable as I have made the assumption the H4n and microphone are correctly manufactured and working correctly.
So how did the microphone signal get to both tracks? Did you record via the XLR connections at the base of H4n or did you go into the 3.5mm socket on the back of the H4n?

My gut feeling is that you probably used an XLR to 3.5mm cable on your microphone? and if so it was wired incorrectly.
This problem is becoming a weekly discussion problem on several forums.

OK how to solve the problem….. use a correctly manufactured interconnecting cable. For VO signals its often better in post production to use a single track panned to the centre, doing it this way eliminates any possibility of this occurring.
And as a final point ALWAYS ALWAYS listen to your complete audio mix in stereo then do it again in mono.

[Antony Bui]

Wow I didn’t know that could happen. This RODE only takes XLR so it’s connected to the H4N without any kind of adapter. Thanks to your explanation I managed to “fix” it by changing the audio to dual mono in FCP and then muting one of them. It’s not ideal but it’s enough for what I need to do.

I will definitely investigate my settings and test in mono in the future. Thank you very much Brian!!! Problem solves and future issues prevented 😀

[Ty Ford]

Hello Anthony and welcome to the Cow Audio Forum,

I’m thinking maybe you did something in FCP. Which version are you using?

Regards,

Ty Ford
Cow Audio Forum Leader

Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford’s Blog

[Antony Bui]

I don’t think it was anything in FCP since the raw audio files straight from the H4N had the problem. I’m using FCPX 10.0.7. It’s something with the H4N or the mic itself.

[Jean-christophe Boulay]

Hi Anthony,

Phase issues can also happen when the same source is recorded by two different microphones positioned at different distances from the source. If there is a possibility that you were recording through both your Rode mic and the H4N’s built-in mics, that could also explain the issue.

Another cause is when you have the exact same signal on two audio tracks (as would happen if you’re working in stereo with a mono recording) and one of the tracks gets nudged a few samples one way relative to the other track, either through accidental manipulation or some importing workflow weirdness. If the raw files have the issue, this is probably not your problem here, but worth knowing for the future.

Bottom line, when you’re working with off-camera voice, always work with one mono track panned dead center. There is no reason at all to work in stereo with VO, especially if your stereo signal is one mono recording doubled to two tracks. Even with on-camera voice, stereo is rarely justified. What you ended up doing in the end is the way you should do it.
Also, try to always use a proper pop filter when recording voice over. A windscreen often isn’t enough to stop the energy of the plosives and there are some pops in that recording. Google will return quite a few tips on how to make one with household items if the budgy is tighty. One of your girlfriend’s stockings and a clothes hanger can change your VO recordings.

IHTH,

JC Boulay
Technical Director
Audio Z
Montreal, Canada
http://www.audioz.com