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Dec 19, 2018 Spectral Repair is a module available in iZotope RX 7 Standard and RX 7 Advanced audio restoration software that lets you remove and replace unwanted sounds and frequencies in audio. Two things make Spectral Repair much more precise at removing problem sounds than simple EQ’ing or filtering: 1. Visualization of the audio and 2. Algorithm-based audio repair.
- 'Play Frequency Selection' button in RX “Actually, if you could write about anything,” Matt tells me, “that is the biggest tip!” You can use this any time you want to hear exactly what you’ve selected in RX standalone.
- IZotope develops award-winning audio software and plug-ins for mixing, mastering, restoration, and more. RX 7 Standard is the audio repair toolkit used on albums.
- Jan 20, 2005 After making any selection, press shift + R to reverse that selection. IZotope’s Iris 2 is a sample-based synthesizer that takes the power of the spectrogram and makes it available in a comprehensive synthesizer, optimal for complex sound design tasks. Layer up to four different samples, create radical spectral filter selections.
- Mar 21, 2016 Taken from our An Evening with iZotope event, iZotope product specialist Brandon Carroll walks us through RX, a powerful and essential tool for audio cleanup. He uses the spectral repair function.
Standalone Workflow
- Open the audio file in the RX Audio Editor or send it via RX Connect.
- Open the Corrective EQ module [Option+Shift+7].
- Engage a high-pass filter to remove the most apparent rumble and to make any other static filtering gestures before applying the De-noiser. In this example, we also reduced some of the prominent ‘S’ frequencies around 7 kHz and a tonal component of the background noise around 800 Hz.
- Then open the De-noise module [Shift+4]. The De-noise module has two modes: Dialogue and Spectral. We’ll use Dialogue mode for this example.
- Inside the Dialogue tab, we can set the De-noise algorithm to adjust automatically (which is used for sounds that vary throughout the program), or we can manually learn a noise profile that the algorithm can reduce constantly across the program. Since this example has steady background noise throughout, we’ll start in Manual mode.
- Now we’ll Learn a noise profile by selecting a passage of at least one second of pure noise in your audio and clicking Learn.
- The six Threshold Nodes will automatically set themselves based on the noise profile. These nodes represent different parts of the frequency spectrum, and their thresholds can be adjusted (and automated) individually.
- Click Preview and adjust settings to the program material, starting with the Reduction slider and then adjusting multiband threshold nodes if necessary.
- Once you have arrived at the optimal setting for your audio, click Process.
Spectral repair is a tool for interpolating selected areas on a time-frequency spectrogram. It is able to provide higher quality than the Declicker tool for long corrupted segments of audio (above 10 ms).
Izotope Rx Play Frequency Selection 2017
![Izotope Rx Play Frequency Selection Izotope Rx Play Frequency Selection](https://www.izotope.com/en/learn/matt-mccorkle-rx-for-sound-design/_jcr_content/root/sectioncontainer_main/flexcontainer/flexcontainer_center/flexcontainer_center_top/image_1537027265_cop_178103091.coreimg.82.1280.png/1580499731290/6-spectrogram-selection-with-the-frequency-inverted.png)
Spectral repair can be used to remove (or attenuate) certain unwanted sounds from recordings, such as squeaky chairs, coughs, dropped objects, mobile phones ringing, etc. It can also close up gaps in audio by using advanced resynthesis techniques.
Understanding Spectral Repair Modes
Spectral Repair has several tabs representing different modes of interpolation.
- Attenuatemode is suitable for recordings with background noise or where noise is the essential part of music (drums, percussion) and should be accurately preserved. It's also good when unwanted events are not obscuring the desired signal completely. For example, this mode can be used to bring noises like door slams or chair squeaks down to a level where they are inaudible and blend into background noise.
- Replacemode can be used to replace badly damaged sections (such as gaps) in tonal audio.
- Patternmode is suitable for badly damaged audio with background noise or for audio with repeating parts. It searches surrounding areas for a similar piece of audio and blends it into the selection.
- Partials+Noisemode is the advanced version of Replace mode. It restores harmonics of the audio more accurately with control over the Harmonic sensitivity parameter. This mode links detected harmonics by synthesizing them through the selection, and interpolates the rest of the signal using the Replace method.
Processing Limitations
Izotope Rx Elements
Depending on the mode and settings, Spectral Repair will have varying limits to the amount of audio that can be processed in your selection.
- Unlimited - Attenuate when in Vertical mode
- 10 seconds - Attenuate Horizontal or 2D, Replace modes;
- 4 seconds - Pattern, Partials+Noise modes.
Applying Spectral Repair
![Crack Crack](/uploads/1/2/6/4/126446955/378937456.png)
To start working with Spectral Repair, switch to the spectrogram view by dragging the waveform/spectrogram opacity slider to the right. Next, identify the unwanted event on a spectrogram and select it using a time-frequency selection tool (it is not necessary to select a surrounding region, select only the event you want to repair). You can audition this selected time-frequency tile by pressing the 'Play selection' button in the RX transport.
Note: Depending on the mode chosen, Spectral Repair
Note: Some unwanted events consist of several separate regions on a spectrogram. In some cases, it's possible to achieve more accurate results by repairing several smaller selections one by one, instead of one large selection. Also, you can use the Find Similar Event tool to save time when searching for and fixing many similar events in large files.
Once you've found the event(s) to repair, select the appropriate interpolation mode (tab). Sometimes it's worth trying several different methods or number of bands to achieve the desired result. Higher number of bands doesn't necessarily mean higher quality! We encourage you to use the Compare Settings window to experiment and find the best settings for the project at hand.
Common parameters for many methods include 'Surrounding region length' that determines how far around the selection will Spectral Repair look for a good signal. 'Before/after weighting' allows to use more information from either before or after the audio for interpolation. For example, if your unwanted event is just before a transient (such as a drum hit) in the audio, you may want to set this parameter to use more of the audio before the selection to prevent smearing of the transient.
See the Reference Guide for descriptions of Spectral Repair controls.