Tutorial on Commonly Used Modules
This is our 3rd article on iZotope’s audio repair tool RX 7.
We will continue to look at editing using different modules.
Though many modules are included, I have chosen a few which I find personally useful and common to take a look at.
We will continue to look at editing using different modules.
Though many modules are included, I have chosen a few which I find personally useful and common to take a look at.
Mar 06, 2015 I used RX 4 Advanced extensively while working on five video projects containing many dialog tracks, music and B roll. The new Leveler module gave me excellent results easily and exceedingly fast, smoothing levels no matter the track’s spectral balance.
iZotope RX 7 Tutorial ③ – Video Access
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De-hum
First take a listen to this sample.
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/03/Hum_Crackle_pre.mp3
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/03/Hum_Crackle_pre.mp3
We can hear a low humming noise as well as a constant crackling sound as well.
Lets try to get rid of these.
Lets try to get rid of these.
We will be using De-hum to remove the hum noise.
Hum noise is usually based around low frequencies in the 50-60Hz range, and is a noise that contains a number of harmonics.
We could select 50 or 60Hz from Base Frequency, but if you want AI to make the choice for you, click the Suggest button at the top.
We could select 50 or 60Hz from Base Frequency, but if you want AI to make the choice for you, click the Suggest button at the top.
This will analyse the sample and Free mode will allow it to set a more accurate frequency.
The hum noise can been reduced greatly but if the voice has been negatively effected as well, we can lower the number of harmonics down right on the brink of effecting the main sound. We can do this from the Number of harmonics fader.
Next lets adjust the amount of cut. You can make changes from the screen, but the frequency points can get shifted in free mode so we’ll enter numerical changes below.
Find a point where the noise isn’t noticeable yet the vocal remains clean.
For the low end, you can cut up until the point where it starts effecting the vocal. We will turn the High-Pass Filter on and cut under 100Hz.
Though you most likely won’t be using the Low-pass-filter, it may be necessary depending on the type of noise present.
If we want to make more detailed edits on the harmonics we can choose a different Linking Type.
For the default ALL setting, moving the slider here will have a slope effect on all frequencies.
By selecting Odd/even you can control the odd and even harmonics separately.
The Slope slider will help lower the reduction effect on higher frequencies.
When None is selected the link is removed, allowing you to control the Gain of individual harmonics.
By selecting Odd/even you can control the odd and even harmonics separately.
The Slope slider will help lower the reduction effect on higher frequencies.
When None is selected the link is removed, allowing you to control the Gain of individual harmonics.
De-Crackle
Next lets look at getting rid of the crackling pop-like noises.
We will be using De-crackle.
We will be using De-crackle.
- Quality:Low will work faster, while High will provide a better sound quality. Medium may yield better results than High depending on the situation, so its best to listen and compare this settings.
- Strength:Determines the strength of the effect, and a higher setting will get rid of more noise but can negatively effect the vocal sounds. Use “Output crackle only” to hear just the crackle sounds and find the right setting.
- Amplitude skew:Allows you to determine the amount of noise editing by the volume of the input signal. Turning it to the right focuses on the louder areas, while turning it to the left will do the opposite. We can set this higher if dealing with clipping noise, but for small detailed crackling noises such as this, it is best to set this parameter on the lower side.
For noise that couldn’t be completely removed, we can try using Spectral De-noise which we took a look at in our previous article.
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Hum_Crackle_processed.mp3
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Hum_Crackle_processed.mp3
As you can hear, we have been able to clean up the audio.
De-reverb
Now lets change the sample audio and take a look at the unique De-reverb.
As the name implies, this helps remove reverb and room reflections in a recording.
First lets hear the sample for this example.
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Reverb_pre.mp3
As the name implies, this helps remove reverb and room reflections in a recording.
First lets hear the sample for this example.
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Reverb_pre.mp3
We can clearly hear the reverb in this sample.
Omnisphere 2.5 update download. We will be using De-reverb on this audio.
Omnisphere 2.5 update download. We will be using De-reverb on this audio.
Though all of these parameters may seem confusing, we can utilise RX 7’s special feature here and get some automatic settings using the Learn button.
To dive a little deeper into the editing, we can leave the Reverb Profile frequency settings set by Learn as is, and adjust the Reduction and Tail length to yield big results.
- Reduction: Increases the amount of reduction of reverb. We want to raise this higher but it will cut out vocal frequencies if set too high, so its best to adjust it to find the right balance.
- Tail length:The further right its pulled the more it works on longer reverb tails. If you get unnatural changes in the vocal sound, be sure to pull this back a little to the left.
- Artifact smoothing:Adjusts the frequency detail of noise removal. Setting it low results in some artefacts in sound, but will increase the amount of reverb reduction. If set higher, you will have less artefacts and a smoother sound, but more reverb will be left over. Its best to listen and find a balance in the middle.
- Enhance dry signal:Increases the volume of non-reverb sounds and expands the dynamic range. This works great on dialogue and human vocals.
The resulting audio after adjusting each parameter is as follows:
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Reverb_processed-1.mp3
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Reverb_processed-1.mp3
Though its not a completely dry signal, a considerable amount of reverb has been edited out.
De-clip
Next, if we happen to accidentally distort audio during recording we can use De-clip to remove clipping noise.
We have a sample prepared for this as well.
* Be aware that this sample is louder than the previous examples.
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Clip_pre.mp3
* Be aware that this sample is louder than the previous examples.
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Clip_pre.mp3
In de-clip we will first setup the threshold of clip sounds. We will use this histogram as a reference but it looks like nothing is displayed at the moment. The histogram will be updated depending on the selected area, so lets first select the portion with vocal audio contained.
Crossover 18 mac. If you still don’t see anything, zoom out in the Histogram. Because the majority of sound is clipping, we can see quite alot reflected in the higher volume areas.
By pressing the Suggest button, it will automatically set the Threshold to the suggested point.
Its clipping to the point that that nothing is visible in the center, so it’s set to 0dB. If the audio isn’t this distorted, we would set the threshold a little below the clip.
The remaining parameters work as follows:
- Quality:If your CPU can handle it we suggest using High. If your computer can’t handle the strain when using this as a plugin, use Medium or Low.
- Makeup gain:Most distorted recordings are too loud to begin with, so we will be lowering this. You could adjust this parameter so that the fixed audio matches the volume of your other takes as well.
- Post limiter:Applies a peak limiter at the end to prevent the edited audio from going over 0dBFS. Its best to tick this box.
Lets hear how the sample sounds after making adjustments.
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Clip_processed.mp3
https://sleepfreaks-dtm.com/wordpress/wp-content/uploads/2020/04/Clip_processed.mp3
The sound is much cleaner and its hard to believe it was distorted.
This completes our look at some commonly used modules in RX 7.
RX 7 covers a vast field of noise/reverb related issues, so be sure to try it out for your own recordings!
RX 7 covers a vast field of noise/reverb related issues, so be sure to try it out for your own recordings!
Purchase here
- CATEGORY:
- Mixing plugins
Leveler
The Leveler module automatically rides the gain in your file to even out the variations of the signal level. The algorithm consists of a compressor with a makeup gain to achieve the a smooth signal that’s aiming towards (though may not exactly hit) a desired Target RMS level. The compressor has the ability to prevent pumping on speech pauses or breathing sounds, using the Optimization mode, for either Dialogue or Music, in addition to the Ess and Breath parameters. The level detector stage includes the K-weighting filter that helps equalize the audible loudness, not just RMS level. However, the Leveler module is designed for the smoothing of overall audio signals, rather than taking an entire signal and using a fixed gain to ensure it hits a loudness compliant LKFS level, the goal of the Loudness module.
This all combines to create a transparent, non-destructive Clip Gain curve, without the color or artifacts of a traditional compressor.
Unlike Loudness module, which applies a constant gain based on Loudness compliant analysis to the whole file, Leveler applies a time-variable gain. For convenience of RX users, the time-variable gain is applied as a Clip Gain envelope, which can be viewed and edited by the user.
Numerical Readouts
These readouts provide you with the Total, Maximum and Minimum readouts for RMS. The total value is the overall RMS of your audio signal, which may inform where you choose to set the Target RMS level parameter.
Optimize for
This switches between two modes, Dialogue and Music. Each mode utilizes a slightly different handling of the noise floor.
Dialogue tends to be audibly juxtaposed against the noise floor, as it’s typically very transient, whereas music often tends to fade into the noise floor, with chords, notes, and other instrumental decays. Switching between these two modes will affect the behavior of the Leveler, and prevent pumping.
Target level
Sets the desired average RMS level of the recording. Note that Leveler uses K-weighted RMS to better level perceived loudness, but that it is not a loudness compliant leveling tool. It uses the Target Level as a guide, but with the goal of smoothing out variations in an audio signal much more transparently than a compressor typically would. As such, it is not unusual to see the resulting output of Leveler not be an exact 1:1 with the defined Target Level. At high target levels, the leveler may not be able to hit the target without clipping, so the target level will not be reached.
Responsiveness
Sets the integration time for RMS level detection. Similar to the attack/release setting on a compressor. Lower settings will result in more aggressive Leveling, useful if a signal has a lot of sudden variations. Higher settings will result in smoother behavior, leveling words or phrases rather than individual syllables. If you find the Leveler is responding to any sudden unwanted sounds, such as a cough, and boosting it, a increase the slider to a higher value to see if this results in less aggressive jumps.
Preserve dynamics
This can be thought of the maximal amount of gain applied by the Leveler, the wider the range of gain adjustments allowed, the further away from the original dynamic range the audio signal will be.
A lower values, the Leveler will preserve fewer of the original dynamics in the audio signal, and at higher values, the Leveler will preserve more of the original dynamics in the audio signal.
Ess reduction
Izotope
Ess reduction is aimed at anyone using the Leveler on dialogue or vocals, and utilizes a smart algorithm, inspired by the DBX 902 De-esser, to detect when ess is present in a signal, and then attenuate it accordingly. This avoids adding any boost to esses, which may otherwise be seen as quiet sounds requiring a boost. The slider sets the amount of ess reduction applied, in dB.
Breath control
This will automatically detect breaths in your vocal takes and attenuate them. This can be an essential tool when editing a dialogue or vocal track by streamlining a task that can be time-consuming when performed manually.
Breath Control automatically analyzes the incoming audio take and distinguishes breaths based on their harmonic structure. If any piece of the incoming audio matches a harmonic profile similar to a breath, the Leveler will apply a Clip Gain adjustment. Different from a 'Threshold' based process in which the module is only engaged once the audio has risen to a certain volume, this feature will perform its analysis regardless of level. This allows for accurate breath recognition with a multitude of quiet or loud dialogue / vocal styles with minimal adjustment of the module's controls.
The slider represents the desired level, in dB, that you wish all detected breaths to be reduced to. This can result in much more natural sounding breath reduction as the detected breaths in your audio are only reduced when necessary. Loud and abrasive breaths will be reduced heavily, and quiet, natural sounding breaths will be left at the same volume. The volume level specified by this slider is a guide, but may not result in exact values.
Limiter
The Leveler has an inbuilt Limiter, in order to avoid introducing any clipping to the audio signal once the Clip Gain envelope has been applied.
This cannot be adjusted, but you’ll see the Clip Gain envelope smooth off an audio signal if you’re pushing peaks close to 0 dB.