removing dv hum from audio

[ulfschack]

Equally irritating as the wind-rips in the small mike-holes on the dv-cam is the eternal buzzing or hum from the tape mechanism. At least you can put a cloth cap on the mike to take the brunt of the wind-factor, but that other noise comes from within.

Before I start on yet another mile-long and winding-road project I'd just like to know if anyone successfully done this and with what application/plug-in

Eagerly awaiting ....

cheers

[theReal]

Haven't tried it, but I guess the Sonic Foundry noise reduction DirectX plugin might be able to do it...

[ulfschack]

Well, first let me apologize to think that someone hasn't had a need for this before me. Cool Edit Pro 2 (free for 21 days) does one helluva job of it. Just find a passage of a couple of seconds where nothing but the noise you want to remove is present. Let the program do a FFT and save it as a template. Then apply it to the whole track.

It didn't just become better and less annoying, it became almost absolutely void of any unwanted noises, while music and voices remained crisp and clear. For a first try I must say it was a total succes! And fast too. Roughly RT/6 on a 2.5 GHz. This method is a given on future DV productions.

cheers

http://www.syntrillium.com/cep/

[theReal]

Just find a passage of a couple of seconds where nothing but the noise you want to remove is present. Let the program do a FFT and save it as a template. Then apply it to the whole track. That's just the way the Sonic Foundry plugin works - I guess it's very similar.

[DDogg]

FYI: I had some 60 Hz hum in a narration take I did the other day using the Cam just as an audio recorder (All my machines induce too much noise). I don't know if this was true AC jum or Cam Noise. I tried the several sample based noise reducers and they did pretty well but did degrade the audio. I finally settled on the preset "60hz hum notch filter using 4 stacked filters" in the Vegas "Track EQ" filter. That did a remarkable job giving me dead silence between word pauses.

[ulfschack]

Yeah, I was kinda hesitant to writing such praise at first bearing in mind all the over enthusiastic newbie advice I've read over the course of the past couple of years ...like whenever I see something new it's automatically fantastic :) It's the kid in me, really. And I hope it never goes away either :)

I guess I'll have to compare now *sigh*

cheers

[Sigma9]

Hi,

why not go fight the trouble at the source? I am using a rather cheap external micro which does the job - no camera noise any more. Besides other advantages (eg., with a longer cable you can get closer to the sound), you wouldnt have to fiddle around with the software denoisers.
OK, if you just do it once, a micro might not be worth the investment, however if one (like you, I suppose) is going to do more shots, I would consider.

At least I am lucky with this solution now.

/Sigma9

[steve_g]

Check that the motor noise really comes through onto your captured audio. I can hear it on my Canon DV if I play it off the camera, but once captured to the PC all seems OK. I have seen this reported in other forums.
It seems that the hum is not on the sound track, but comes through the audio output on the camera.

[ulfschack]

Im my case it's in the stream. I know this because I never play of the cam.