Help! Microphone noise

  • Thread starter Thread starter Libin
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Libin

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Hi! First let me say I am a newbie, don't know too much about recording stuff.

I was trying to record some of my daughter's piano session, but noticed the recorded track has this very annoying humming electric noise, not sure where they are from.

Our room was absolutely quiet, I even turned off the furnace. The humming noise was not heard by my ears, yet they are pretty loud in the track.

I was using:
Canon EOS-5D Mark II with a 50mm lens.
Rode NTG-2 Shotgun condenser microphone
Hosa Technology STEREO MINI/M R/A to XLR/F CABLE - 2' cable.

Low pass filter was turned on. The camera was set about 5-6 feet away from the piano, NTG-2 was mounted on hotshoe pointed to the piano sound board(more or less).

The audio level was set to auto since I don't know what level should I use.

I uploaded the track onto youtube, but since this is my first post, they don't allow me to post URL, Please append following string behind the youtube www website address:
/watch?v=XTqsSqlxP50

The original track was recorded in mov file, audio was:
Stream #0.1(eng): Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s

I had to convert it to mp4 since youtube doesn't recognize mov file and had to downgrade to reduce the file size. The audio quality of above video you watched is:
Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, s16, 357 kb/s

I listened to both the original track and converted youtube one, they are pretty similar. You can hear the humming noise very clearly at the beginning of the track.

Here are my questions:
1 What did I do wrong? Was the microphone level too high?
2 How do I avoid the humming noise next time?
3 As of now, is there a software I can use to eliminate the humming noise from the track already recorded?

Any comments are welcomed!
 
I put in the link to the video, and it says it's private (only those with the link can see it). I would either make the video public, or get your 10 posts so you can post the direct link.
 
Oop! Sorry. Apparent I didn't know how to upload to youtube either. Please try it again, I made it public
 
Also, I tried using audacity's noise reduction feature, it works somewhat, but not without loss ...

Let me just emphasize that this is the first time I ever attempted to record something serious and first time ever trying to edit a sound track. I had basically zero knowledge how recording was like. Any help are appreciated!
 
From what I can hear and I'm using my laptop speakers. However the audio was recorded, it sounds like it went through a compressor. It sounds like it was compressed pretty hard too. It could be it was just the auto level changing at every peak and dip. Bringing up the volume when its quiet and lowering it perhaps quickly when it gets loud. That is why you hear all the noise. I suggest setting the input gain to a single level that doesnt change.
 
I don't hear hum, but do hear the hissing from over-compression - probably the camera's auto setting to keep volume constant.
 
What do you guys mean by compression? The file generated by 5D is huge, I wouldn't think you refer to software compression?

Did some more research on line, apparently I am not alone on this issue. See this post here:
Hissing or static from external mic's anyone? - Canon 5D MKII forum on Vimeo

And this video too:
Untitled on Vimeo
I got the exact same thing: Using internal microphone, there's no hissing but sound quality is low, using external microphone, there's this hissing sound.

This post seems to suggest magic lantern:
5D Mark 2 5dm2 Hissing Noise Rode VideoMic Magic Lantern firmware - YouTube
But I am really not sure if I want to upgrade my 5D's firmware -- I mainly use it as a still camera.

Any more suggestion?
 
Adding one more clip:
Review: RODE Video Microphone - YouTube
You need to turn the speaker volume all the way up.
Pay attention to at about 2:17 when the guy was filming his swimming pool and bird chirpping, he switch from videomic to internal mic, you can hear the hissing noise immedicately subdued.
 
Compression - keeping the volume recorded at the same level. The camera boosts the volume up if its low, reduces it if its high. Most video cameras do this. If you can turn it off and set the recording level manually, it should be better.
 
That type of hardware configuration (XLR to 1/8") is notorious for humming. Don't use the Hosa cable. Everything about that is wrong.

First, you should use a line matching transformer, not a straight cable.

Second, you must use a metal back on the 1/8" connector or you will get hum when running at microphone levels.

Third, you need to make sure the XLR jacket on the mic cable is grounded by the cable. Given the first two glaring flaws with that cable, I'd be surprised if they got this right, either.
 
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