Figure 1: The stand-alone version of iZotope RX 2 Advanced. The right side of the GUI provides access to processing modules. Clicks in the audio file are displayed as three vertical lines in the center of the golden spectrogram, in which the floating waveform overlay is disabled.

• Broadband Noise Spectral Repair Izotope Rx 5
• Broadband Noise Spectral Repair Izotope Rx 2
• Izotope Rx Download
• Broadband Noise Spectral Repair Izotope Rx 1

Mar 06, 2015  For a refresher on RX 4 Advanced’s legacy features, check out my review of RX3 Advanced in the May 2014, issue of Mix. Streamlined Interoperability. RX’s Spectral Repair plug-in—which was a bit of a kludge in previous releases—has been discontinued, made obsolete by the new RX Connect plug-in and alternative DAW interoperability. May 20, 2018  Insert the iZotope RX Dialogue De-noise plug-in on the dialogue track or bus that requires noise reduction. In some cases you may want to insert an EQ plug-in ahead of the Dialogue De-noise plug-in to filter low frequency rumble and make any other broad EQ adjustments. If the noise changes throughout the program: Start in  Auto  mode.

1. Izotope are the latest developers to release a suite of tools for tackling problem audio. As well as the usual noise-reduction algorithms, RX also includes clip reduction and an advanced 'spectral repair' module.
2. Aug 19, 2010  For broadband noise, check out this and this. If I had to go for one or the other, I'd go for Waves, because X-Crackle is irreplaceable to me for turning lav rustle into smooth 'cloth movement', while Z-Noise is very close to RX denoiser. Then, there is the spectral repair which is unique in RX.
3. For broadband noise, check out this and this. If I had to go for one or the other, I'd go for Waves, because X-Crackle is irreplaceable to me for turning lav rustle into smooth 'cloth movement', while Z-Noise is very close to RX denoiser. Then, there is the spectral repair which is unique in RX thus far.

iZotope’s critically acclaimed RX 1 restoration software offered impressive processing for removing clicks, hum, broadband noise and even isolated events such as chair squeaks from audio files. Two updated versions of the software, RX 2 and the more-powerful RX 2 Advanced, add a multitude of features for even more effective restoration and easier archiving.

The software comes in both stand-alone and plug-in versions. The stand-alone version includes a world-class spectrogram with floating waveform overlays and several processing modules that can be used either independently or in combination (see Fig. 1). The Declipper, Declicker & Decrackler, Hum Remover, Denoiser and Spectral Repair processing modules included in the stand-alone version can also be instantiated as separate DAW plug-ins in RTAS, AudioSuite, VST, MAS, AU and DirectX formats. (The Spectral Repair plug-in includes essentially the same spectrogram as the stand-alone software; the plug-in provides offline processing and is not compatible with some hosts.) The stand-alone versions of RX 2 and RX 2 Advanced also offer a 6-band equalizer, gain adjustments (including four types of fades), L/R channel-balancing controls (including phase rotation) and a real-time spectrum analyzer.

NEW TOOLS
Why upgrade from RX 1? RX 2 includes new freehand (paint-brush and lasso) and automatic (Magic Wand) tools for selecting unwanted events (clicks, dog barks, fret buzz and so on) for attenuation or removal in its spectrogram. You can adjust pre- and post-roll around selections in the spectrogram. The new Decrackler is indispensable for restoring vinyl recordings. The Hum Remover can automatically find the base frequency in need of processing, and the Denoiser and Declicker algorithms have been improved since RX 1’s release. You can chain multiple processing modules together when batch-processing files. Your edit history is automatically saved when you quit, and it’s restored after a crash.

youtube id=”mSsXrPxJ2rc”With this post, I can finally emerge from my dark hole of a home office to announce that is now out of teaser phase and into release phase. Djay 2 ipad ipa 2. Why a dark hole?

RX 2 Advanced includes all of RX 2’s features and more. An adaptive Denoiser mode removes background noise that changes over time, a lifesaver for video post. A new Deconstruct module lets you accentuate or attenuate noisy and pitched components of sound independently. (Imagine making a vocal track sound more breathy.) RX 2 Advanced features third-party plug-in hosting (one AU, VST or DirectX plug-in at a time) for processing spectrogram selections and batch processing. Other features include proprietary 64-bit SRC sample-rate conversion, MBIT+ dithering, Radius pitch-shifting and time-stretching, automatic azimuth re-alignment (for tape restoration) and a time-stamped log (invaluable for forensics and archival work).

The SRC, Time/Pitch and Spectral Repair processors work only offline in both RX 2 and RX 2 Advanced. All the other modules work in real time. I reviewed RX 2 Advanced in stand-alone mode and its plug-in versions in Digital Performer Version 7.21 (DP) using an 8-core Mac Pro running OS X 10.5.8.

Figure 2: The Denoiser plug-in allows independent attenuation of tonal and broadband noise components.

CLEAN-UP TIME
RX 2 Advanced proved invaluable while re-recording (engineering the final mix for) an independent documentary video. During one outdoor scene, the Denoiser greatly tamed broadband noise from distant traffic that all but buried very quiet dialog. I could achieve more than 4 dB of noise reduction without producing any watery artifacts or dulling high frequencies. In another scene, the Declipper completely rebuilt squared-off waveforms and purged distortion on a dialog track that had been recorded too hot and had clipped hard. Amazing.

The Hum Remover includes a mode that supposedly lets you hear only the hum component of an audio file for easier adjustment of control settings, but I heard total silence instead. While moving some of the plug-in’s controls, audio is momentarily passed through unprocessed, which is a distraction when fine-tuning settings. Despite these annoyances, the Hum Remover was phenomenally effective in removing 60Hz hum and its first and second harmonics from a dialog track recorded with a poorly grounded lavalier mic. I could completely remove the hum without significantly changing the track’s timbre. And on a Foley track, Free mode let me manually dial in the corrective frequency and Q settings to eliminate a 153Hz hum of unknown origin.

On a voice-over track, Declicker seamlessly removed lip smacks while only very slightly reducing depth. And the Denoiser transparently reduced broadband noise around 9 dB on a noisy music track (see Fig. 2).

THE MIRACLE WORKER
Spectral Repair can remove sounds that no other processor can touch. It uses interpolation of surrounding material to seamlessly fill in the resulting holes. I felt most comfortable using the plug-in version of Spectral Repair. As the audio files for the video didn’t include timecode metadata, exporting to the stand-alone version would have made subsequent lock-to-picture of the repaired files prone to error after importing them back into DP. That said, the interfaces for the stand-alone and plug-in versions need improvement.

The plug-in version offers real-time previewing (allowing you to hear the results of your control settings before rendering), while the stand-alone version currently doesn’t and requires a workaround. With the stand-alone version, you can undo, change your settings and process your selections again to hear the result of different settings. Alternatively, you can use the included Compare function to cache the effect of different settings for comparison purposes before committing permanently; after the caching is completed, you initiate playback to hear the cached results in turn. Neither the Undo nor Compare workarounds allow pre- and post-roll playback around the events you wish to process (the plug-in allows this), forcing you to evaluate the processing of split-second-duration events in isolation from the surrounding material you wish to preserve.

Despite its shortcomings, the stand-alone version of Spectral Repair offers a few advantages over the plug-in. Its spectrogram has a scrolling playback wiper that makes it much easier to identify the exact location of noises you want to eliminate. (iZotope hopes to include this feature in the plug-in in a future release.) The stand-alone version can also automatically find similar events to the one you’ve currently selected; this makes it much easier to, for example, remove several chair squeaks in turn without having to separately search for and manually select each one for processing.

I got my best results using the Lasso tool to select multiple objects—by drawing a border around them with my mouse while holding the Shift key—to process in the spectrogram. To my amazement, I was able to completely remove three very closely spaced and loud broadband clicks embedded in a music production’s final mix without inflicting any audible penalty whatsoever on the desired material. (The frequency bandwidth of the clicks was too wide for the Declicker to be effective.) Like removing sugar from a cake after it had already been mixed and baked, Spectral Repair did the impossible.

MAYBE I’M AMAZED
Most of the modules for RX 2 Advanced work brilliantly. The Hum Remover is a little buggy but nevertheless yields terrific results. The user interface for Spectral Repair needs improvement but won’t stop you from attenuating or removing seemingly intractable noises. The learning curve is a little steep due to a somewhat poorly written and insufficient operating manual.

Few products astonish this seen-it-all engineer. RX 2 Advanced—especially Spectral Repair—floored me. RX 2 Advanced offers a world-class toolset that’s indispensable for anyone involved in audio restoration and archiving, forensics, post-production, music mastering and cleaning up noise-riddled tracks recorded in poorly isolated home studios.

Mix

contributing editor Michael Cooper is the owner of Michael Cooper Recording in Sisters, Ore.

Click on the Product Summary box above to view the RX 2 Advanced product page.

Overview

Spectral Repair intelligently removes undesired sounds from a file with natural-sounding results.

This tool treats selections within the spectrogram/waveform display as corrupted audio that will be repaired using information from outside of the selection.

Select the noise you want to repair and Spectral Repair will reduce it to the level of the noise floor, replace it with audio from around the selection, or generate entirely new audio to fit the selection.

Attenuate

This mode removes sounds by comparing what’s inside a selection to what’s outside of it.

Attenuate reduces spectrogram magnitudes in the selected area to match magnitudes from the surrounding area, resulting in the removal of the sound without leaving an audible gap behind.

Attenuate does not resynthesize any audio. It modifies dissimilar audio in your selection to be more similar to the surrounding audio.

Attenuate 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, Attenuate 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.

Attenuate: Controls

• BANDS: Selects the number of frequency bands used for interpolation.
  
  • A higher number of bands can provide better frequency resolution, but also requires wider surrounding area to be analyzed for interpolation.
    
  • A lower number of bands is ideal for processing short selections or transient signals.
    
• SURROUNDING REGION LENGTH: Defines how much of the surrounding content will be used for interpolation.
  
• STRENGTH: Adjusts strength of attenuation.
  
• MULTI-RESOLUTION: The multi-resolution mode allows for better frequency resolution for the interpolation of low-frequency content and better time resolution for the interpolation of high-frequency content.
  
• BEFORE/AFTER WEIGHTING: Gives more weight to the surrounding audio before or after the selection.
  
• DIRECTION OF INTERPOLATION: Determines where the material used in the repair process is located in relation to the current selection.
  
  • HORIZONTAL: Signal to the left and right of the current selection will be used for interpolation.
    
  • VERTICAL: Signal above and below the current selection will be used for interpolation.
    
  • 2D: Signal above, below, to the left and to the right of the current selection will be used for interpolation.
    

    Note: Direction Of Interpolation control availability

    • Replace, Pattern and Partials + Noise tabs only utilize Horizontal mode and do not display this option.
      
    
    

Replace

The Replace tab can be used to replace badly damaged sections (such as gaps) in tonal audio. It completely replaces the selected content with audio interpolated from the surrounding data.

Replace: Controls

• BANDS: Selects the number of frequency bands used for interpolation.
  
  • A higher number of bands can provide better frequency resolution, but also requires wider surrounding area to be analyzed for interpolation.
    
  • A lower number of bands is ideal for processing short selections or transient signals.
    
• SURROUNDING REGION LENGTH: Defines how much of the surrounding content will be used for interpolation.
  
• MULTI-RESOLUTION: The multi-resolution mode allows for better frequency resolution for the interpolation of low-frequency content and better time resolution for the interpolation of high-frequency content.
  
• BEFORE/AFTER WEIGHTING: Gives more weight to the surrounding audio before or after the selection.
  

Pattern

This mode finds the most similar portion of the surrounding audio and uses this to replace the corrupted audio.
Pattern mode is suitable for badly damaged audio with background noise or for audio with repeating parts.

Pattern: Controls

• BANDS: Selects the number of frequency bands used for interpolation.
  
  • A higher number of bands can provide better frequency resolution, but also requires wider surrounding area to be analyzed for interpolation.
    
  • A lower number of bands is ideal for processing short selections or transient signals.
    
• SURROUNDING REGION LENGTH: Defines how much of the surrounding content will be used for interpolation.
  
• MULTI-RESOLUTION: The multi-resolution mode allows for better frequency resolution for the interpolation of low-frequency content and better time resolution for the interpolation of high-frequency content.
  
• PATTERN SEARCH RANGE: Selects the length of the audio segment used in a search for a suitable replacement interval. For example, setting it to 5 seconds will allow search within ±5 second range from the selection.
  

Partials + Noise

The advanced version of Replace mode. It restores harmonics of the audio more accurately with control over the Harmonic sensitivity parameter.

Rx 4 izotope. This mode allows for higher-quality interpolation by explicit location of signal harmonics from the 2 sides of the corrupted interval and linking them together by synthesis.

Partials + Noise is able to correctly interpolate cases of pitch modulation, including vibrato. The remaining of non-harmonic material (“residual”) is interpolated using Replace method.

Partials + Noise: Controls

• BANDS: Selects the number of frequency bands used for interpolation.
  
  • A higher number of bands can provide better frequency resolution, but also requires wider surrounding area to be analyzed for interpolation.
    
  • A lower number of bands is ideal for processing short selections or transient signals.
    
• SURROUNDING REGION LENGTH: Defines how much of the surrounding content will be used for interpolation.
  
• HARMONIC SENSITIVITY: Adjusts amount of detected and linked harmonics.
  
  • Lower values will detect fewer harmonics
    
  • Higher values will detect more harmonics and can introduce some unnatural pitch modulations in the interpolated result.
    
• MULTI-RESOLUTION: The multi-resolution mode allows for better frequency resolution for the interpolation of low-frequency content and better time resolution for the interpolation of high-frequency content.
  
• BEFORE/AFTER WEIGHTING: Gives more weight to the surrounding audio before or after the selection.
  

Surrounding Region Display

• SURROUNDING REGION SHADING: When using the Spectral Repair module, your selections will be shown with a dotted line surrounding your selected region. This dotted line is directly controlled by the Surrounding Region and Before/After Weighting controls inside of your Spectral Repair modules, and provides a visual representation of your set values.
  
  • The surrounding region is the region that RX uses for interpolation of the selected region. The data from the surrounding region is used to restore the selected region.
    

Workflow

Applying Spectral Repair

1. To start working with Spectral Repair, switch to the spectrogram view by dragging the spectrogram/waveform transparency balance slider to the right.
   
2. Next, identify the unwanted event on a spectrogram and select it using a selection tool (use the time-frequency, brush, lasso or magic wand tools to fit your selection to the corrupted audio)
   
3. You can audition just the signal in your selection by pressing the Play Selection button in the RX transport.
   
4. Once you’ve found the event(s) to repair, select the appropriate Spectral Repair mode from the tabs at the top of the Spectral Repair settings window.
   
5. You can use the Compare Settings functionality to audition the processing before applying it, or click the process to apply the active Spectral Repair tab’s settings.
   

Broadband Noise Spectral Repair Izotope Rx 5

More Information

This section contains useful information, examples and tips for getting the most out of the Spectral Repair module.

Visual Example

The following image shows the selection before processing on the top and the selection after processing with Spectral Repair on the bottom.

Processing Limitations

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 only.
  
• 10 seconds — Attenuate Horizontal or 2D; Replace modes.
  
• 4 seconds — Pattern, Partials + Noise modes.
  
• Longer selections will automatically adjust processing to use the correct mode.
  

Spectral Repair as an alternative to De-click processing

When used with a time selection, Spectral Repair is able to provide higher quality processing than De-click for long corrupted segments of audio (above 10 ms).

Broadband Noise Spectral Repair Izotope Rx 2

Example use cases for Spectral Repair

When used with a time/frequency, lasso, brush, or wand selection, it can be used to remove (or attenuate) unwanted sounds from recordings, such as: squeaky chairs, coughs, wheezes, burps, whistles, dropped objects, mic stand bumps, clattering dishes, mobile phones ringing, metronomes, click tracks, door slams, sniffles, laughter, background chitchat, digital artifacts from bad hardware, dropouts from broken audio cables, rustle sounds from microphone movements, fret and string noise from guitars, ringing tones from rooms or drum kits, squeaky wheels, dog barks, jingling change, or just about anything else you could imagine.

Spectral Repair can also effectively repair gaps or replace audio intelligently by using advanced resynthesis techniques.

Increase efficiency with the Find Similar Event Tool

Izotope Rx Download

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.
You can use the Find Similar Event tool to save time when searching for and fixing many similar events in large files.

Use the Compare Settings window to experiment with Spectral Repair processing

Sometimes it’s worth trying several different methods or number of bands to achieve the desired result. A 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.

Adjust Surrounding Region Length and Before/after weighting to perfect your processing

Broadband Noise Spectral Repair Izotope Rx 1

Common parameters for many modes include Surrounding region length which determines how far around the selection Spectral Repair will look for a good signal. Before/after weighting allows you to use more information from either before or after the selection 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 into the selection.