May 01, 2017 1. Open an audio file in the RX Audio Editor or send it using RX Connect. Select the distorted portions of the audio and open the De-clip module. Set the Threshold to identify where the De-clip algorithm should begin to apply processing. For this example, a threshold of –8.4 dB worked well. Click Preview to hear the results. Adjust the threshold and quality settings as necessary. Some dialogue problems can’t be fixed. Distortion, errant sirens, wind gumming the microphones—it’s impossible. The truth is, with iZotope RX, you can fix all sorts of previously impossible problems. Here are six tips to get you out of a dialogue bind.
Time & Pitch
Time & Pitch uses iZotope’s sophisticated Radius™ algorithm to give you independent control over the length and pitch of your audio. It is useful for retuning audio to fit in a mix better, or adjusting the length of audio to deal with BPM or time code changes.
Time & Pitch’s Pitch Contour tab can be used for faster pitch shifting with the ability to correct variations in pitch over time.
iZotope Radius
iZotope Radius™ is a world-class time-stretching and pitch-shifting algorithm. You can easily change the pitch of a single instrument, voice, or entire ensemble while preserving the timing and acoustic space of the original recording. iZotope Radius is designed to match the natural timbres even with extreme pitch shifts.
Algorithm
You should use Solo mode only when processing a single instrument with a clearly defined pitch. The human voice is a good candidate for solo mode, as are most stringed instruments, brass instruments, and woodwinds. For most other types of source material, Radius mode will usually offer better results. If speed is important, use the Radius RT mode.
Solo
In Solo mode, the adaptive window size can significantly affect the quality of Radius's output. If the adaptive window size is too small, you will hear a squeaking noise which sounds like the pitch of the audio is changing very rapidly. If the adaptive window size is too large then the sound will become grainy as you will begin to hear portions of it being repeated.
A good approach is to start with the default window size of 37 ms. If the results are unsatisfactory, increase the window size until the squeaking noise described above does not occur. If you cannot get the distortion to disappear, switch to Radius mode for processing.
Lower pitched instruments and voices may require a longer adaptive window size than the default, but very long adaptive window sizes can cause audible repeating slices of audio.
Formant Correction
Formants are the resonant frequency components of voice that tend to be perceived as characteristics like age and gender. You can shift formants independently of pitch and time by enabling Shift Formants.
Typically you will leave the Formant Shift Strength set to 1 (full strength) and the Formant Shift Semitones set to 0. If you hear what sounds like an EQ adjustment to your audio, you can try lowering the strength to reduce this artifact. To achieve special effects, for example to change the perceived gender of a human voice, try adjusting the semitones to a value other than 0.
Stretch & Shift Controls
Stretch Ratio
Determines how much the resulting audio will be stretched in time. Values between 12.5% and 100% will cause the audio to speed up without affecting pitch, resulting in a shorter audio file. Values between 100% and 800% will cause the audio to slow down without affecting pitch, giving you a longer audio file.
BPM Calculator
If you are using Radius to process audio for a tempo change, you can also adjust the stretch ratio with the BPM Calculator.
Controls the amount of pitch shifting up or down that will be applied to the audio.
Algorithm
The Algorithm drop-down menu has three options:
- Radius — designed to work well with polyphonic material such as mixes with more than one instrument, as well as non-harmonic material such as drum loops or rhythmic audio. This is the highest-quality option for most sources.
- Solo Instrument — designed for monophonic pitched material such as a stringed instrument or human voice.
- Radius RT — good quality, polyphonic, but faster than Radius.
Transient Sensitivity
Determines the algorithm’s handling of transient material. Higher values will result in better preservation of individual transients after processing.
When stretching percussive material, you usually want transient sensitivity set to its default value of 1. If transients in your audio are being 'smeared', a higher value of 2 will tighten up transience at the expense of incurring heavier processing on non-transient audio.
Bowed instruments such as the violin and cello are especially affected by the transient sensitivity setting. If you hear a stuttering artifact, lower the transient sensitivity to eliminate it.
Noise Generation (Radius mode only)
Helps noisy material (like sibilance or snare drums) sound more natural when processed.
This control will generate noise instead of stretching the noise that is already present in the signal and creating new tones. Higher values of the noise generation parameter will cause Radius to generate noise more often, but can cause some phase artifacts.
Pitch Coherence (Radius mode only)
Controls the preservation of the natural timbre of the processed audio.
The Pitch coherence control in the Radius control panel helps preserve the timbre for pitched solo voices, such as human speech, saxophone or vocals. While traditional vocoders can smear these signals in time and randomize phase, the pitch coherence parameter of Radius preserves phase coherence for these signals.
High values of pitch coherence will avoid phasiness in Radius's output at the expense of roughness (modulation) in processed polyphonic recordings. Try turning this up for better results if you’re processing a solo voice or a small group of related instruments.
Phase Coherence (Mix mode only)
Preserves the coherence of phase between the left and right channels of the processed audio.
This should be increased if there's any change in the perceived stereo image after using Radius. It can be decreased when processing a multichannel signal where different channels contain completely different instruments.
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Adaptive Window Size (ms) (Solo mode only)
Adjusts the window size in milliseconds of Radius' Solo algorithm.
If the adaptive window size is too small, you will hear a squeaking noise which sounds like the pitch of the audio is changing very rapidly. If the adaptive window size is too large then the sound will become grainy as you will begin to hear portions of it being repeated.
Increase this if you have trouble getting good results pitching or stretching low-pitched instruments or voices.
Shift Formants
Processes formant frequencies independently of other pitch and time processing.
When this option is enabled, formant frequencies can be shifted independently of other pitch shifting performed by Radius.
When Radius performs pitch-shifting without Formant Correction, it will shift these resonant frequencies along with the rest of the audio.
- Strength — adjusts the amplitude strength of the formant correction filter.
- Shift — how much formant frequencies are shifted. Typically this control can be set to 0, which leaves the formant frequencies unshifted during processing. Adjust this control to fine-tune the formant correction algorithm or for special effects.
- Width — controls the bandwidth of the formant detection filter. Smaller values of this control will offer more precise formant correction in the processed audio. Higher values will include a wider band of formant frequencies.
Pitch shifting single instruments (especially bass instruments) can benefit from some adjustments to formant correction. Try enabling formant correction and moving the strength between 0.1 and 0.2. Move the Formant Correction semitones part of the way towards your pitch shift amount. For example, if you're pitch shifting +4 semitones, move the Formant Correction Semitones between 2 and 3. This can help bring back subtle percussive elements in the original source material.
The formant frequencies of the human voice can actually shift slightly when we sing. You can use the Formant Correction Semitones control to compensate for this. For example, if pitch shifting a human voice by +7 semitones, try setting the Formant Correction semitones between 0 and +2 for more natural results.
Pitch Contour Controls
The Pitch Contour mode of the Time & Pitch module lets you change the pitch of a selection over time. This can be used to quickly correct small pitch variations or gradual pitch drifts over time.
The Pitch Contour changes pitch by continuously changing the playback speed of the audio. The effect is similar to speeding up or slowing down a record or tape deck while it is playing back.
Because the Pitch Contour uses resampling to synchronously change time and pitch, it cannot be used to adjust pitch without also adjusting time.
Pitch Contour
The horizontal axis shows the length of your current selection. If you have no selection, the horizontal axis represents the entire length of your file.
The vertical axis shows the amount of pitch shifting that will be applied. A curve through the top half of the display will create a higher shift in pitch and shorten the audio correspondingly. A curve through the lower half of the display will create a lower shift in pitch and lengthen the audio correspondingly.
You can correct a gradual pitch drift over time by adjusting the points at the far left or right of the display, drawing a straight sloping line from the beginning of your selection to the end. These points are locked to the vertical axis.
Clicking on the contour display will create a new pitch node. You can create up to 20 pitch nodes to achieve very complicated pitch shifts.
Clicking and dragging a pitch node to move it around will change the pitch curve.
Double clicking on a pitch node will set its value to 0 (no change at that point).
Right clicking on a pitch node will delete it.
Holding control/command while dragging will give you fine control over a pitch node’s position.
Smoothing
Larger values create a smoother pitch curve when multiple pitch nodes are present. This is useful when correcting a nonlinear change in pitch.
Denon dj ds1 scratch live 2. Reset
Clears all pitch nodes and returns the Smoothing control to its default value.
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.
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.
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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. Garageband for ipad air.
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.
Izotope Rx Output Distorted Effects
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.
We will be using De-reverb on this audio.
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.
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!
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- Mixing plugins