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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: gihl on December 24, 2022, 10:23:32 AM

Title: City sounds and sudden noise
Post by: gihl on December 24, 2022, 10:23:32 AM
I usually record city sounds with my Zoom F3 recorder.
Most of the parts marked in orange in the attached picture are vehicle or sudden wind noise.
I wonder if there is a way to reduce these parts while maintaining good sound in post-production.
Your input would be appreciated.  :)
Thanks.

Title: Re: City sounds and sudden noise
Post by: gihl on December 25, 2022, 06:21:14 AM
I wonder if it is enough to use Adobe Audition's single band compressor or if there is a better way.
Title: Re: City sounds and sudden noise
Post by: if_then_else on December 25, 2022, 09:32:43 AM
I usually record city sounds with my Zoom F3 recorder.
Most of the parts marked in orange in the attached picture are vehicle or sudden wind noise.
I wonder if there is a way to reduce these parts while maintaining good sound in post-production.
Your input would be appreciated.  :)
Thanks.

Probably best to avoid or at least minimise the unwanted effects while recording.

Some interesting video tutorials on field recording (open + stealth recording guides)
https://www.youtube.com/watch?v=TKBzjSSaKXU
https://www.youtube.com/watch?v=5qFq8a4zHFQ

For post-production there are of course tools like iZotope RX or the Acon Digital restauration suite.
Title: Re: City sounds and sudden noise
Post by: dactylus on December 25, 2022, 09:58:34 AM
I usually record city sounds with my Zoom F3 recorder.
Most of the parts marked in orange in the attached picture are vehicle or sudden wind noise.
I wonder if there is a way to reduce these parts while maintaining good sound in post-production.
Your input would be appreciated.  :)
Thanks.

What kind of mics are you using and what windscreens are you using with those mics?  Movo offers a wide assortment of affordable windscreens.

https://www.movophoto.com/collections/windscreens
Title: Re: City sounds and sudden noise
Post by: gihl on December 25, 2022, 12:00:01 PM
Probably best to avoid or at least minimise the unwanted effects while recording.

Some interesting video tutorials on field recording (open + stealth recording guides)
https://www.youtube.com/watch?v=TKBzjSSaKXU
https://www.youtube.com/watch?v=5qFq8a4zHFQ

For post-production there are of course tools like iZotope RX or the Acon Digital restauration suite.

Thanks for your advice and links. :)
In this case, what tools are effective when using iZotope RX?

p.s. I just realized that there is no attached image. So I just uploaded an example image.
Title: Re: City sounds and sudden noise
Post by: gihl on December 25, 2022, 12:01:32 PM
What kind of mics are you using and what windscreens are you using with those mics?  Movo offers a wide assortment of affordable windscreens.

https://www.movophoto.com/collections/windscreens

I use Audio-Technica AT822 mic, Rycote BBG Windshield and BBG Windjammer.
Thanks.
Title: Re: City sounds and sudden noise
Post by: nassau73 on December 25, 2022, 12:23:58 PM
You might find it more helpful to work in the spectrogram view where you can actually see how the noise is distributed.

As If_Then_Else mentioned, a post tool such as Izotope RX would be helpful (although I'm not familiar if similar capabilities exist in other programs). You should be able to get away with the standard version of RX.

Just as an example, I had an outdoor recording where we would get gusts of wind off the ocean during the show. In the spectrogram, you could see the wind as a bright color in the low area of the view. Using the paint brush tool, highlighting the bright (wind) area and simply rendering the "Attenuate" function in the Spectral Repair module diminished the wind noise in the recording to a point where, yes it was there, but it was no longer the intrusive element that it once was.
Title: Re: City sounds and sudden noise
Post by: gihl on December 27, 2022, 09:53:05 AM
Thanks for your advice and tips.
I'll have to study Adobe Audition or Izotope RX. ;D
Title: Re: City sounds and sudden noise
Post by: Gutbucket on December 27, 2022, 10:17:02 AM
Spectral editing is able to attenuate specific sounds, and can be quite transparent.  But you will need to target each occurrence.

Limiting / compression attenuates everything that exceeds a threshold level which you determine.   It automatically affects everything"too loud", but needs to be set carefully to not end up sounding squashed and lifeless. 

Parallel compression (bottom up compression) works in the opposite way by raising the level of the quiet stuff while not effecting the loud parts.  That will bring up the low-level details in the recording while leaving the dynamic peaks unsquashed, and tends to sound more natural.  But it will also bring up the noise-floor of the recording along with the quiet parts.

Each approach has its benefits and drawbacks.
Title: Re: City sounds and sudden noise
Post by: gihl on December 29, 2022, 08:15:54 AM
Thanks for the explanation about limiting/compression and parallel compression.
After I experience the Single-Band Compressor a little more, I will also learn parallel compression.
Thank you again.
Title: Re: City sounds and sudden noise
Post by: Gutbucket on December 29, 2022, 09:14:05 AM
Single-band vs multi-band compression is an additional difference in how a compressor works.  Either may be used in series or parallel.

Limiting / compression attenuates everything that exceeds a threshold level which you determine.   It automatically affects everything"too loud", but needs to be set carefully to not end up sounding squashed and lifeless.

..or worse, end up suffering from audible compression artifacts, which range from outright distortion to the compressor obviously clamping down and releasing when the threshold is exceeded, causing background sounds of relatively constant level to "pump" up and down in volume as the compressor engages and releases.

Learning how to set the compressor parameters carefully while listening is key to avoiding those kinds of problems.

Multiband compression splits the signal up into multiple frequency ranges that get compressed separately then recombined again inside the compressor, which can reduce artifacts occurring across different frequency ranges.  But best to lean how a single-band compressor works first before complicating things.
Title: Re: City sounds and sudden noise
Post by: Gutbucket on December 29, 2022, 09:19:50 AM
Often the best approach is to use just a bit of a few different dynamic manipulation methods in combination, as long as you are willing to commit the necessary time.  For example, it can be best to do something like the following, with each step targeting a different aspect, but all of them working collectively achieve the amount of reduction in dynamic range that is needed without the listener being made aware of the manipulation or the tools being used:

1) Fix outstanding and particularly egregious individual problems.  Reduce the level of specific noises, sporadic over-loud things, whistles and other unwanted stuff using direct editing and/or spectral editing / restoration tools.
2) Control excessively high peaks using a conventional single-band or multi-band compressor set to only kick in briefly when those things occur. This is "top down" in terms of dynamics, and takes the most skill to set correctly so as not to be bad sounding. 
3) Reduce overall dynamic range and bring up the low-level details using parallel compression. This is "bottom up" in terms of dynamics, and is easier to do transparently.