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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: panther65 on January 28, 2008, 09:51:52 PM

Title: Random noise/chirping/artifacts in various parts of the recording
Post by: panther65 on January 28, 2008, 09:51:52 PM

I patched into the board at a recent show and got some random chirping and  distortion in various spots during about 20 minutes of the recording. It came from the board as I've heard an alternate copy with the same artifacts. It's a bit tough to tell, but they seem to be from about 5k to 10k. Is there a way to at least tame these noises?
I  don't have a silent portion where the noises occur however. I use Audacity and Adobe Audition 3 but I have access to other programs.

http://rapidshare.com/files/87621087/sun_also_sets_distortion_16bit.wav.html

Title: Re: Random noise/chirping/artifacts in various parts of the recording
Post by: John Kary on January 30, 2008, 09:17:20 AM

Sounds like a bad cable on-stage.  Since you patched the board, and it sounds really faint, it was probably a bad wire to one of the monitors, and the crackling sound bled through to one of the mics.

Here's a trick to removing random little noise like that when using Waves X-Noise...  take a noise-print (Learn) off the unaffected audio of that song by letting the noise-reduction tool learn as much as possible over a similar sounding part of the song.  Then highlight the noisy part and process the noise-reduction plugin over the bad part--but set it in Difference mode.  The "good" audio should filter through, while the crackling is suppressed.

Title: Re: Random noise/chirping/artifacts in various parts of the recording
Post by: panther65 on January 30, 2008, 09:38:20 AM

Thanks so much kuky for going to the trouble of listening to that. I will give that program a try.

Title: Re: Random noise/chirping/artifacts in various parts of the recording
Post by: ironbut on February 01, 2008, 09:13:12 PM

You have a PM. I hope this helps. Like I said, I think I could have gotten all of it if I'd been more careful and taken the time, but I just took a minute or two to let you know RX could fix it as if it was never there.

Title: Re: Random noise/chirping/artifacts in various parts of the recording
Post by: panther65 on February 02, 2008, 10:55:30 AM

Thanks very much IB. I just noticed my PM. I screwed around with Izotope, but it seemed there were so many instances of these abnormalities that it would be hard to get rid of them. It's a great program and I will continue to experiment with it.
I put a box around what appeared to be the noise and attenuated. Should I do it differently?

Title: Re: Random noise/chirping/artifacts in various parts of the recording
Post by: panther65 on February 02, 2008, 03:10:39 PM

Many thanks to IB for suggesting this outstanding program. I have at his suggestion iZotope RX and it is just fabulous. I can manually go into the spectrogram of any file and take out any offending noises. In my instance there were several strange chirps at about 5500hz and with iZotope I was able to get in there and draw a box around the artifact and remove it without removing any of the audible bandwidth. Truly powerful.

Title: Re: Random noise/chirping/artifacts in various parts of the recording
Post by: ironbut on February 03, 2008, 08:23:19 PM

Glad your getting the hang of it. I've found that one of the dangers of this software is you start getting rid of every little bitty bit of noise. Stuff that you'd normally live with gladly. Then you look up and see that 2-3 hours have gone by. Sometimes it's like magic. BTW, have you looked at the video tutorials they have in the support section of their site? 

Title: Re: Random noise/chirping/artifacts in various parts of the recording
Post by: panther65 on February 04, 2008, 08:51:22 AM

I will take a look at the videos. I haven't done that yet.
You're right, I spent darn near the entire day on Saturday working on getting the noises out. My wife was ready to kill me.