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SonicStudio 5 NoNOISE (NN-101)

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1. 0 SONIC SOLUTIONS SonicStudio 5 NoNOISE NN 101 1996 Sonic Solutions All rights reserved SonicStudio 5 NONOISE NN 101 This manual as well as the software described in it is furnished under license and may only be used or copied in accordance with the terms of such license The information in this manual is furnished for informational use only is subject to change without notice and should not be construed as a commitment by Sonic Solutions Sonic Solutions assumes no responsibility or liability for any errors or inaccuracies that may appear in this book Except as permitted by such license no part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical recording or otherwise without the prior written permission of Sonic Solutions SONIC SOLUTIONS INC SONIC MAKES NO WARRANTIES EXPRESS OR IMPLIED INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE REGARDING THE APPLE SOFTWARE SONIC DOES NOT WARRANT GUARANTEE OR MAKE ANY REPRESENTATIONS REGARDING THE USE OR THE RESULTS OF THE USE OF THE SONIC SOFTWARE IN TERMS OF ITS CORRECTNESS ACCURACY RELIABILITY CURRENTNESS OR OTHERWISE THE ENTIRE RISK AS TO THE RESULTS AND PERFORMANCE OF THE SONIC SOFTWARE IS ASSUMED BY YOU THE EXCLUSION OF IMPLIED WARRANTIES IS NOT PERMITTED BY SOME STATES THE ABOVE EXCLUSION MAY NOT APPL
2. Because noise is random energy this composite FFT appears smoother than the display produced by the Do Frequency Analysis command Interpolating the Estimate Before the Noise Estimate can be used to provide threshold data for denoising it must be additionally smoothed and perhaps adjusted to account for the presence of desired signal within the noise There are two ways to accomplish this smoothing 6 8 SonicStudio Version 5 Broadband Denoising 1 After deriving the Noise Estimate select the command Interpolate Estimate located directly beneath Take Noise Estimate in the NoNOISE menu This causes the system to do a best fit approximation from the composite data displayed as a smooth Estimate Line connecting a series of boxes drawn over the composite FFT If the Noise Estimate is derived from a clean sample of noise this method produces an accurate measurement of the underlying noise floor As with a Waveform or Frequency Analysis display you can use the View menu commands along with the Left and Right Gates to view any portion of the panel in detail Zoom In 1 Zoom Out 0 zoom To Gates 6 Zoom To Previous xP The Noise Estimate data can be modified by moving the position of the boxes up or down by holding down the Option key and grabbing the box with the mouse More is said about this in the section on editing the Noise Estimate SonicStudio Version 5 6 9 Getting Started
3. 0 00 Processing Context Width seconds 0 050000 Parameters Replacement Order 400 Click Rate per second Replacement Center per cent 40 0 Threshold sample level Display Options Don t compute display reductions open Save save As Default Cancel Display Reductions The Sonic System waveform display is factored to show any length of sound from a few samples to several hours with equal ease It does this by creating separate files that represent the waveform at various levels of magnification These files are created when a file is loaded onto the system and whenever a processing function such as declicking alters the audio waveform To save time in processing you can select the Don t compute display reductions option Reduction files are used only when the display shows more than about 20 seconds of audio This display level is too broad to identify clicks and glitches with any precision and declicking generally is not affected if the reduction files are not updated by the declick pass SonicStudio Version 5 4 15 Getting Started Declick Parameters Replacement Width Definition The declick algorithm is capable of filling a gap ranging from 4 to 4096 audio samples Replacement Width determines the number of samples that will be replaced when removing the click Its value is expressed in seconds from 0 00009 to 0 092 seconds 0 09
4. Hardware requirements 1 5 High cutoff frequency 6 18 HiShelf filter 2 14 Hiss displaying in signal 6 10 IN button 6 15 Increasing RAM memory 4 3 Initial threshold 4 7 Initial threshold parameters 4 9 Input Sound Flle 5 3 Insert button 6 14 Interference low frequency 3 10 Interpolate Estimate com mand 6 4 6 9 Interpolate Gate command 3 2 Interpolating the estimate 6 8 Interpolator types listed 3 4 K Kaiser Bessel filter 2 6 L Launch button 2 12 4 4 6 24 Launch Click Detect dialog 4 4 4 7 4 9 Launch declick dialog 4 20 Launch Declick Job dialog il lustrated 4 15 Line inputs 6 17 Low Frequency Cutoff param eter 6 22 M Managers command 4 5 5 4 Manual Declicking 1 2 Manual declicking option 3 1 Maximum attenuation param eter 6 2 Maximum reduction atten 6 18 Memory overflow avoiding 4 3 Menu illustrated 1 7 Menu NoNoise 1 7 3 1 Mixing desk setting up 6 13 Mono declicking 4 3 Mono NoNoise Preferences dialog illustrated 6 23 N Next Click command 4 22 No DC filter 2 22 No padding option 2 6 Noise estimate 6 1 Noise estimate file 6 2 Noise estimate line 6 11 Noise estimate commands 6 3 Noise broadband 6 1 None option 2 6 Notch filter 2 19 O Open button 6 16 Open Est button 6 16 Open Params button 6 17 6 24 Order 2 15 Output Sound File 5 3 Overview 1 1 P Pad with Zeros option 2 6 Padding technique 2 6 Parametric filter 2 17 Passripple
5. viewing and modifying the click list 4 2 SonicStudio Version 5 Production Declicking Mono and Stereo Declicking Automatic declicking is entirely monaural a restriction inherent in the process Many materials for declicking are monaural as well such as 78 RPM recordings from the 1930s Stereo declicking is performed by declicking each channel separately Processing Long Files Click detect and declick operate on an entire sound file at once for reasons having to do with the management of the click list in relation to the sound file itself During click detect the click list is held entirely in Macintosh RAM Long files produce correspondingly lengthy click lists If the material has a lot of clicks as well memory overflow may result There are three ways to overcome or avoid this problem Load source materials as two or more shorter files After processing use the Sonic System s editing features to splice the files together Alter the detect parameters so that a smaller portion of clicks are detected then use multiple passes to eliminate all clicks Increase the amount of RAM available by assigning more RAM to the SonicSystem application Select the SonicSystem icon from the Mac Finder and type Command I This opens an information box that includes a field for the amount of memory assigned As larger blocks of RAM memory have become more affordable the last option is recommended SonicStudio
6. 2 18 SonicStudio Version 5 Complex Filtering Notch Filter The Notch filter is a special case of the Parametric filter in which the gain at the center frequency is set to minus infinity effectively eliminating all signal at that frequency Frequency Response of a Notch Filter center frequency 63 dB bandwidth Specifying a notch filter requires only two parameters center frequency and bandwidth The gain at the center frequency of a notch filter is fixed at co dB so that the center frequency is eliminated completely Center Frequency cf The range of the Notch filter s center frequency is the same as for other filters on the Sonic system from 0 1 Hz to 22 050 kHz Bandwidth bw The Notch bandwidth is specified in Hertz with a range from 1 Hz to 22 kHz High and Low Shelving Filters HiShelf and LoShelf Shelving filters apply a fixed boost or cut to all frequencies beyond the cutoff frequency Shelving filters have two variable parameters These are different from those of Parametric filters SonicStudio Version 5 2 19 Getting Started Cutoff Frequency cf Cutoff Frequency is the point where the signal is boosted or cut by 3 dB or by 1 2 the specific boost cut if less than 3 dB Boost Boost or Cut applies to signal above in the case of HiShelf or below in the case of LoShelf the cutoff frequency The range of boost or cut is 24 dB Extended High and LowShelf Filters EH
7. Bandwidth bw 2 14 2 17 Bandwidth parameter de noising 6 21 Bandwidth equation 2 15 Boost 2 15 2 17 Broadband denoising 1 4 6 1 C C type interpolation 3 6 Capturing real time denoise 6 17 Center frequency 2 14 Center frequency cf 2 14 2 17 Center width 4 7 Center width defined 4 10 Cepstrum analysis 2 5 Clear Enable command 4 27 Click detect 4 1 Click Detect Amplitude dia log illustrated 4 25 Click Detect file 3 8 Click Detect file creating 3 9 Click Detect Filter file 4 7 Click list 4 1 Click list editing commands listed 4 24 Click List File Format 4 30 Click LIst Management sub SonicStudio 5 User Manual menu 4 24 Click procedure 4 30 Clicks finding 3 8 Clicks removing 3 3 Clip fraction 5 6 Clip Fraction parameter 5 4 Complex filters overview 2 1 Context width defined 4 17 Context width settings 4 17 Corrected clicks marking 4 14 Creating a click list 4 4 Cutoff frequency cf 2 14 D D type interpolation 3 7 Damping factor parameter 5 7 DC De Emphasis 2 23 Declick command 4 13 Declick commands listed 4 2 Declicking production 4 1 Decrackle Info dialog illus trated 5 2 Decrackle module 5 1 Decrackling 1 3 Dekrackle command 5 3 Delete Click command 4 28 4 29 Delete Input checkbox 6 24 Delete input command 2 13 Delete Input Option 5 5 Denoise command 6 22 Denoise parameters 6 17 Denoising broadband 1 4 De RIAA filter 2 23 Detect Clicks command 4
8. High Cutoff Frequency is fixed at about 22 050 Hz It has been found that this parameter is seldom used in practice so it was deleted from the real time parameter set Maximum Reduction Atten This value in negative decibels sets the maximum attenuation to be applied in any frequency band A setting of 0 dB produces exactly no noise reduction The higher more negative this value is set the greater the reduction in noise but with increasing danger of producing audible artifacts in the audio signal The amount of noise reduction perceived is normally about half the maximum attenuation 3 dB depending on the material and the other denoise parameters A good starting point for the maximum attenuation is to take the amount of perceived noise reduction you wish to obtain and then double it If for example you wish to obtain a perceived noise reduction of around 8 dB then start with a maximum reduction setting of 16 dB 6 18 SonicStudio Version 5 Broadband Denoising Typical values for this parameter range between 10 mild 20 moderately aggressive and 30 extreme If the maximum attenuation setting is too extreme ambience or high frequency response may be lost Threshold Thres The Noise Estimate defines the curve of the thresholds that apply to each of the over 2 000 individual frequency bands used by the denoise process The Threshold parameter allows the curve as a whole to be moved up or do
9. Version 5 Complex Filtering 1 Select Set Filters from the NoNOISE menu This opens the Background Filter Selection dialog where you can enter the specifications for the filters you wish to apply You can select filter types from the list displayed in the upper portion of the dialog Background Filter Selection Filter Menu Parametric Notch HiShelf LowShelf HiPass LowPass No DE Emph DeEmph No DC DeEmph RIAA DeRIAA BandPass BandStop EPara EHighShelf ELowShelf Selected Filters Parametric f 0 00 q 0 00 b c 0 00 Add Filter Remove Filter Set Values E Done Read Write To add a filter to the Filter Specification file 1 Select the desired filter type from the list by clicking on it with the mouse SonicStudio Version 5 2 9 Getting Started 2 Click on the Add Filter button or double click on the desired filter in the list of selections A filter of the type selected is added to the specification list Once you have added a filter to the list you must specify the parameter values that apply to that filter Filter Type Presence Description Single resonance 0 00 0 00 0 00 Cancel To set the values for a filter in the Filter Specification list 1 2 Select the filter by clicking on its name in the list Click on the Set Values button or double click on the
10. Version 5 4 3 Getting Started Generating the Click List A click list is produced automatically by the click detect pass A click list can also be generated manually but is not recommended for the normal case The list resulting from a detect pass may be edited New click sites may be added and existing sites disabled or deleted Specify Source File Set Processing Parameters and Filter Sound File click here gt Filter Spec File lt click here gt Initial Threshold Center Width seconds Wing Width seconds Wing Weight Launch Click Detect Job 5 0 0 001 0 002 1 0 The command Detect Clicks opens a dialog box to specify the input sound file an optional filter spec file for the detect pass and with four variable processing parameters The function of these parameters and their use are described later in this chapter Initially the default settings are recommended To launch a click detect pass 1 Select Detect Clicks from the NONOISE menu 2 Click with the mouse next to the word Sound File Select the file to be declicked from the Mac file select dialog box 3 Make any desired changes to the detection parameters and filter specification in the Launch Click Detect dialog box 4 Click on the Launch button to start the pass 4 4 SonicStudio Version 5 Production Declicking Click detect
11. adapt the denoising operation to the characteristics of the material Broadband Denoising operates by means of analysis and resynthesis A Fast Fourier Transform FFT frequency analysis is performed on a sample of noise from the material to be processed The level of noise in each of 2048 individual frequency bands is determined The output of this analysis is a Noise Estimate In actual denoising the source material is also subjected to a 2048 point FFT analysis The level of signal in each frequency band or bin in Sonic System terminology is compared against a threshold level determined by the Noise Estimate Based on this comparison the processing algorithm determines whether a given band at that particular instant contains audio signal or only noise If a frequency bin is found to include elements of the desired signal it is left untouched If it is determined that the signal in that band is only noise the level of that band is reduced by an amount determined by the SonicStudio Version 5 6 1 Getting Started Maximum Attenuation processing parameter The results of this comparison and adjustment for all bands is a modified version of the original FFT frequency analysis A reverse FFT is then performed using the new adjusted version of the signal analysis reconstituting the audio signal with noise attenuated by the specified amount Because the Denoiser operates in more than 2 000 individual bands the removal of noise is
12. and perhaps a higher order may be needed to focus the Detect File on the click energy between say 6 500 and 9 000 Hz Unfortunately much musical signal typically resides in this band That makes click detection in such files somewhat problematic Low Frequency Interference Many older 78 RPM disk recordings are characterized by an abundance of low frequency energy In some cases these low frequency sounds change quite rapidly and violently The B Type interpolator has only a small area of the soundfile in which accurately to identify the low frequency components in a signal Because of this there is some potential for error in the interpolation When this happens a characteristic artifact is sometimes inserted into the soundfile It sounds like a low level thump or thunk Under such circumstances the best results usually are achieved when the source soundfile is first filtered aggressively to roll off the low frequency noise Since the bandwidth of many older disk recordings was severely limited to begin with it is often possible to apply a 2d or 3d order hi pass filter with a hi frequency as high as 50 60 or even 70 Hz In addition to assisting the B Type interpolator this procedure also has the beneficial effect of removing much low frequency noise that is annoying in its own right such as hum or turntable rumble Thumps Dropouts and Such Although the bulk of anomalies removed using the NoNOISE System are clicks the i
13. area of interpolation in relation to the marked click site Clicks are often followed by some amount of ringing making it necessary to continue replacement for some time after the click itself In transcribing a phonograph record for example the stylus and tonearm resonate in response to the impulse of a scratch on the record producing a damped oscillation that extends for some time after the click This ringing is not detected by the click detect functions Replacement Center shifts the replacement area to the left or right in relation to the click center according to a percentage from the left edge A setting of 0 percent positions the click at the left edge of the replacement area while a setting of 50 percent places the click directly in the middle A setting of 100 percent positions the click at the very right edge of the replacement area If Replacement Center is set so that the ringing of the click extends beyond the Replacement Width the ringing is not interpolated and will be heard in the program Not only that the ringing will be used as context information causing erroneous interpolation Recommended Settings Adjust this parameter to ensure interpolation of any ringing Large clicks more than 0 010 seconds in length can exhibit a lot of ringing Setting the Replacement Center between 5 and 25 percent will ensure that the ringing will fall within the replacement area For 78 RPM record clicks 40 percent is a good value t
14. by the formula Q cf bw Boost Boost indicates the gain applied at the Center Frequency The Parametric filter can supply boost cut of 24 dB SonicStudio Version 5 2 17 Getting Started Extended Parametric EPara Filters Extended Parametric filters provide flatter response in the boost cut region A Parametric filter is a simple resonance while an extended presence filter has a flat region centered on the frequency that is boosted or cut The order denoted by n 2 through 4 determines the slope of the skirts or abruptness of the transitions Center Frequency cf The mid point of the band affected The Parametric filter s center frequency may be selected over a range of 1 0 Hz to 22 050 kHz Bandwidth bw The Parametric filter is a resonance type filter Its bandwidth in Hertz may be translated to filter Q by the formula Q cf bw Boost Boost indicates the amount of gain applied at the Center Frequency The Parametric filter can boost cut by 24 dB Filter Order The Order of a filter corresponding to the value of n 1 to 4 in the filter selected controls the slope of the filter s response curve A first order filter has a slope of 6 dB per octave Slope increases by 6 dB per octave for each increment of 1 to the filter s order StopRipple The maximum change in dB in the stopband the range boosted or cut A setting of 0 5 dB means a maximum EQ alteration of 0 5 dB due to the filter
15. found This is generally in the lower portion of the frequency spectrum The components of the audio signal usually are visible as prominent more or less evenly spaced spikes in the analysis display This is why if an Estimate must be taken in presence of signal it is advised to avoid sections of overly dense or non harmonic material The Noise Estimate Line can be modified by pressing the Option key and using the mouse to drag the boxes superimposed over the line The boxes can be moved only on the vertical axis When the mouse is released the Noise Estimate Line is redrawn to run through the new position of the box SonicStudio Version 5 6 11 Getting Started If for example a number of piano harmonics are infecting the estimate the boxes can be moved so that the Noise Estimate Line follows the valleys that represent the underlying noise floor cutting off the peaks of the piano s notes This type of modification requires you to exercise skill and judgment The ability to extrapolate a useful Noise Estimate Line from a contaminated noise sample will grow with the operator s experience Saving the Estimate When you are satisfied that the Noise Estimate Line in the display represents the underlying noise floor effectively the Estimate must be saved before it can be used in a denoising run To save the interpolated and edited Noise Estimate e Select the command Write Estimate from the NoNOISE menu The
16. frequency components 2 6 SonicStudio Version 5 Complex Filtering More information on windowing and analysis in general may be obtained from the references listed at the end of this appendix Kaiser Bessel Filter Parameters This is a single parameter that applies only to the Kaiser Bessel type It defines a window function that applies to the analysis Recommended Settings For purposes of analysis for Complex Filtering the setting for the Frequency Analysis are most often used in their default settings Transform Type DFT Discrete Fourier Transform Padding Technique Pad with Zeros e Transform Size Exact e Window Function Hamming The Filter Parameters are not active unless the Kaiser Bessel window type is selected SonicStudio Version 5 2 7 Getting Started Creating the Filter List Once you have determined the frequency components to be removed or attenuated you can create a list of filters and filter parameters for processing This list is known as the Filter Specification file Background Filter Selection Filter Menu Parametric LowPass RIAA EHighShelf Notch HiShelf LowShelf No DC Emph DeEmph DeRIAA BandPass BandStop ELowShelf HiPass No DC DeEmph EPara Selected Filters add filter Remove Fter Sef values Done Read write To create a Filter Specification file SonicStudio
17. left and right Likewise if the character or level of the noise floor can be heard to change at all during the recording then the best results are be obtained by dividing that piece into sections to be denoised individually After denoising the individual sections can edited together to create a seamless whole The Noise Estimate should be taken from a relatively short segment in a quiet part of the recording to be denoised Optimum results are obtained when the Noise Estimate is taken from a section of pure noise between about 0 3 and 0 5 seconds in length with a minimum of around 100 milliseconds 0 1 seconds SonicStudio Version 5 6 5 Getting Started The first concern in selecting a segment for analysis is that it represent the noise floor throughout the recording In many cases there is an apparently clean segment of noise prior to the start of program Beware of such segments as they may not represent the noise in the remainder of the recording It is not uncommon for recording engineers to fade up or punch in prior to the start of music leaving an early clean segment containing only a portion of the real noise floor leading to an inaccurate estimate In some instances there may be no section where the noise can be measured without signal Under such circumstances select a section that is relatively quiet and free of non harmonic sounds such as cymbals or bells When forced to take a Noise Estimate in the pre
18. name of the filter This opens a dialog listing the parameters that apply to the selected filter Each filter type has specific parameters that apply described later in this chapter To enter a desired value for a filter parameter 1 2 3 Select the entire field containing the value by double clicking or dragging with the mouse Type in the desired value Press the Tab key to step to the next field 2 10 SonicStudio Version 5 Complex Filtering 4 Once parameter values have been entered for the filter click on the OK button to return to the Filter Selection dialog Saving the Filter List Once you have entered a set of filters and parameters into the filter list you must save the completed list to a file before you can use it to process a sound file To save the completed list as a Filter Specification File 1 Click on the Write button 2 Assign a name for the file or use the default that appears in the Mac file select dialog 3 Save the file Once you have entered and save the desired filter list close the Filter Specification dialog by clicking on the Cancel button Reading a Previously Saved File Previously stored filter lists may be reopened and edited to change the configuration of filters or the parameter values To read in a filter file list 1 Open the Filter Specification dialog 2 Click with the mouse on the Read button 3 Select the file to be read in Once a filter l
19. narrow Wing Width is preferred When using the pre filter detect algorithm by entering the name of a filter spec file in the Launch Click Detect dialog box Wing Width should be at least two times longer than Center Width In this algorithm Wing Width also corresponds to the minimum spacing of clicks that will be detected If two clicks of roughly similar amplitudes are closer together than the Wing Width neither will be detected If the Wing Width is made too small however it may interact with signal causing normal transients to be detected and eliminated as clicks Normal music waveforms such as male voice trumpet and trombone sounds exhibit impulsive behavior that can be mistaken for clicks If the Wing Width is much less than one waveform period the detector will sometimes list a spurious click at the beginning of each period If the source material includes strong low frequencies setting Wing Width to 10 15 or even 20 milliseconds will eliminate this problem but at the risk of not detecting some clicks separated by less time Wing Weight Definition The NoNOISE click detector subtracts total spectral energy in the wings surrounding a possible click site from the energy within the site area as defined from the Center Width This difference value is used to determine valid clicks to be eliminated SonicStudio Version 5 4 11 Getting Started Wing Weight is a coefficient between 0 and 1 applied to the wings ene
20. of a signal peak and read the frequency from the labels at the lower left and right of the panel You may use these values to set notch or other filters to remove that particular frequency In the example above the noise component around 15 kHz is obvious in the full scale display Low and mid frequency information is less evident squeezed into the far left of the frequency scale To see what is happening in the lower frequencies use the gates to zoom in Low and Low Mid Frequencies Peak 60 120 and 180 Hz Peaks In the example above frequency components are identifiable at 60 Hz line frequency as well as at the harmonic frequencies of 120 and 180 Hz These should be clearly audible as AC Hum even though they are at fairly low levels 2 4 SonicStudio Version 5 Complex Filtering However another noise component is evident at around 40 Hz This component might not be heard as easily because it is near the edge of the audible band and may be partially masked by the hum components It is likely to become more audible once the major hum components are removed so it is best to remove it at the same time Frequency Analysis Preferences You may specify many of the details of the frequency analysis algorithm using the Frequency Analysis Preferences selected from the Preference command in the File menu Freq Analysis Prefs Select Transform Type OFT Autocorrelation Cepstrum Select Padding Techn
21. precise and can leave the original audio signal unaffected The Denoising Process There are three stages in the application of Broadband Denoising Analysis Ideally a short section of pure noise is isolated and subjected to a special frequency analysis The analysis is evaluated by the operator and if necessary adjusted for optimal results The result of this analysis is stored as a Noise Estimate file This file is used by the denoiser to set the threshold level in each of more than 2 000 individual frequency bands Testing and Adjustment The denoising software is run in its realtime form so that you can hear the results of processing and adjust the processing parameters until the best results are obtained Processing If desired the output of the realtime denoise process may be captured back to the sound disk or transferred to an output device such as digital audio tape 6 2 SonicStudio Version 5 Broadband Denoising More commonly the parameter settings derived from realtime denoising are used to set up a background denoising pass This provides processing of the complete source file or a desired section of it while the operator continues editing or other operations The Noise Estimate The first step in denoising is to derive a Noise Estimate from the recording to be denoised The Noise Estimate is the fingerprint of the noise as analyzed from the sound waveform display It determines local threshold
22. the detection part of the Decrackle algorithm in which audio samples are separated into good and bad categories The synthesis process then replaces the samples that are deemed bad with synthesized material that matches the surrounding sound The Clip Fraction is the percentage or fraction of the samples that will be left in the good category The range of the parameter is from 0 to 1 00 These samples will pass through the Decrackle process unchanged The higher the Clip Fraction the less aggressive the decrackling If the Clip Fraction is set to 1 0 the output file will be a copy of the input file For heavier decrackling make the Clip Fraction smaller to 0 85 0 80 or even as low as 0 75 Any lower is not recommended as there will be too little of the original signal to provide a basis for resynthesis Lowering the Clip Fraction by only 0 05 is enough to make a noticeable difference If the Clip Fraction is set too high then there will be some amount of crackle remaining in the program If the Clip Fraction is set too low you may begin to decrackle good audio which could result in low frequency artifacts audible thumps Synthesis Order The Synthesis Order determines the precision of the Decrackler s re synthesis In general the larger this number the cleaner and more artifact free the output The default value of 75 is suitable for the majority of source materials If low frequency thunks occur in the processed output tr
23. the results in that case depend very much on the audio context Note Be sure that the click to be removed lies entirely between the Left and Right Gates The Declicking interpolators use the area immediately outside the gates to determine the spectrum of the synthesized replacement audio Because of this poor results will be obtained if any part of the anomaly is left outside the Left and Right Gates Removal 1 From the NoNOISE menu select the Interpolate Gates command 2 Choose an interpolator type from the pull right menu that appears The five interpolator types available are A B C D and E Details on the use of each type are provided in a later section of this manual 2222 Freie mm Tat M Restore Bar T 00 00 24 15 40 Clicks after Interpolation The interpolation algorithm analyzes the anomaly identified and constructs replacement sound After the replacement sound is inserted to substitute for the anomaly ared gray on aB amp W monitor bar above the waveform extending over the area that has been repaired This Restore Bar indicates that sound has been replaced in this area of the waveform 3 4 SonicStudio Version 5 Manual Declicking NN 101 If the results produced by declicking are not acceptable the original sound may be restored using Restore Gates from the NoNOISE menu To restore a previously interpolated section of audio to its original stat
24. to activate real time denoising Once the denoising has been patched in any signal through that channel strip will be processed Playback may be controlled from the Transport Panel or by returning to the Edit Decision List display Real time denoising remains active until the dialog box is closed by clicking on the DONE button SonicStudio Version 5 6 15 Getting Started Reading in the Noise Estimate For the denoising process to work meaningfully it must be supplied with a Noise Estimate Generally the Noise Estimate used will be one prepared from the source material itself as described previously To open a Noise Estimate for real time denoising 1 Click the button labeled Open Est 2 Select the Estimate file to be used from the Macintosh file select dialog box that displays The name of the selected estimate appears to the right of the Open button If desired different Estimates may be read in and the results of processing with each compared Adjusting and Saving the Processing Parameters There are five denoise processing parameters that can be adjusted from the Real Time NoNOI SE dialog box The top set of sliders controls the Insert 1 channel and the lower sliders control Insert 2 if the system is equipped with a second NoNOISE card for stereo real time denoising These five parameters are described in detail in the next section of this chapter Note There is a lag of 2 3 seconds between the adjustment
25. 2 21 Peak distortion removing 5 8 Phon 4 30 Procedure using NoNoise 1 8 Production declicking 1 3 Q Q parameter 2 14 SonicStudio 5 User Manual R Rate parameter 4 26 Rate defined 4 20 Read button 2 11 Read Click List command 4 6 4 22 Reading a filter file 2 11 Reading a noise estimate 6 12 Reading the click list 4 21 Reading the noise estimate 6 16 Real Time Denoising com mand 6 14 Realtime denoising 6 13 Real Time Denoising dialog 6 24 Real Time NoNoise dialog 6 25 Real Time NoNoise Prefer ences dialog illustrated 6 15 Removing hiss 6 1 Removing peak distortion 5 8 Replacement center parame ter 4 19 Replacement center defined 4 19 Replacement center settings 4 19 Replacement order 4 17 Replacement order defined 4 18 Replacement order settings 4 18 Replacement Width setting 4 10 Replacement width defined 4 16 Replacement width settings 4 16 Requirements hardware 1 5 Restore bars 3 7 4 14 Restore file 3 1 Restore Gates command 3 5 4 14 RIAA filter 2 23 Ringing deleting 4 19 S Save as Default button 6 17 Save Params button 6 17 Saving parameter settings 4 7 Saving the filter list 2 11 SCSI terminator removing 1 5 Semicolon placing 4 31 Set Filters command 2 9 Set Rate command 4 26 Set Threshold command 4 25 Set Values button 2 10 Setting the Bandwidth pa rameter 6 19 Setting the Bandwidth pararmeter 6 21 Setting the Low Frequency C
26. 4 Disable Click command 4 27 Display reduction 4 15 Do Frequency Analysis com mand 2 3 Do Frquency Analysis com mand 6 8 Don t compute display reduc tions option 4 15 Done button 6 15 Done With Click List com mand 4 29 Dropouts 3 11 E E type interpolation 3 7 Editing the click list 4 21 Editing the noise estimate 6 11 EFX board 6 15 Emphasis filter 2 22 Enable Click command 4 26 Estimating noise 6 3 Extended Mixing Desk option 2 14 Extended parametric filters 2 18 F Fast Fourier Transform 6 1 FFT see Frequency Analysis 1 2 File deleting 2 13 File filter adc 4 8 Filter command 2 12 Filter specification file 2 8 Filter creating a list 2 8 Filter DC De Emphasis 2 23 Filter De RIAA 2 23 Filter emphasis 2 22 Filter HiShelf 2 14 Filter No DC 2 22 Filter notch 2 19 Filter order 2 20 Filter parametric 2 17 Filter recommended settings 2 7 Filter RIAA 2 23 Filter shelving 2 19 Filter spec file 4 7 Filter StopRipple 2 15 filter adc file 4 8 Filtering complex 1 2 Filters overview 2 1 Fit Estimate from Gates com mand 6 10 Fit Estimate technique 6 11 Force Click Width command 4 28 Fourier Transform FFT 1 2 Frequency Analysis 1 2 Frequency analysis using 2 2 Frequency center 2 14 G Gates using 3 1 6 7 Generally 6 20 Grab More Data option 2 6 SonicStudio 5 H Hamming filter 2 6 Hanning filter 2 6 Hardware configuration dia gram 1 5
27. 8 BROADBAND DENOISING The Denoising Process isisa i a Ea a E E 6 2 The Noise Estimate eee eee 6 3 Realtime Denoising EA EEE EEA E AEA A 6 13 Denoise Parameters n naunan naaran cece eee ees 6 17 Background Denoising o 6 22 SonicStudio Version 5 1 System Overview NoNOISE is the world s premier tool for restoration of vintage and problematic audio recordings NoNOISE s advanced real time and out of real time processes isolate and eliminate audio artifacts such as hiss scratches hum mechanical and impulsive noise NONOISE uses the power of the Sonic System an advanced modular audio workstation that also provides comprehensive editing and mastering capabilities NoNOISE is not a single process or software module but a set of powerful tools to remove bothersome noise without damage to audio program NoNOISE is applicable to restoration of old recordings removing unwanted noises from field recordings and repairing audio materials that have suffered damage SonicStudio Version 5 1 1 Getting Started NONOISE Tools Audio artifacts come in many types and every restoration job is unique NONOISE consists of a group of linked tools for analysis and processing In using NoNOISE you will apply your listening skills and knowledge to determine how the individual tools may be applied to achieve the desired results FFT Analysis The Frequency Analysis Fourier tra
28. File lt click here gt File Replacement Width seconds Launch Declick Job Context Width seconds u Processing Replacement Order 400 Click Rate per second Parameters and Options Replacement Center per cent 40 Threshold sample level E Don t compute display reductions Store Recall Parameter A Open Save Save As Default Cancel Settings To launch a Declick pass 1 Select Declick from the NoNOISE menu N Specify the sound file to be declicked 3 Make any desired changes to the parameters and options 4 Click Launch to start the declick pass As with click detection there are variable parameters that you may adjust These are described later in this chapter Initially the default settings may be used with generally good results SonicStudio Version 5 4 13 Getting Started The click list is implicit in the input file If a declicking pass is requested on a sound file that does not have a click list that is click detection has not been performed on that file the system advises you when the job is loaded for execution Warning A TDeclickJob Execute launchDeclick returned error code 1557 declickInit No clicks to do Did you restore previous run Ordinarily this means that a click detect pass must be performed before th
29. Frequency Cutoff is usually left set around 50 100 Hz If cutoff is below 25 Hz there may be artifacts because wavelength exceeds the analysis window d Denoising Broadband denoising can also be run as a background process producing a new denoised sound file Background denoising is commonly used to create a complete file after refining parameter settings and Noise Estimates using the real time version of the process Denoise Launch Real Time Roae fime Peaoise To start a background denoising job 1 Select the command Denoise from the NoNOISE menu A file select dialog box is used to choose the file to be denoised 3 Take0002 D Source 1 D Source 2 6 22 SonicStudio Version 5 Broadband Denoising If the selected file is one channel of a stereo pair the system prompts you to include the other channel as well Each channel is processed separately Once the file or files are selected the Mono NoNOISE Preferences dialog box appears Mono NoNoise Preferences Source Sound File Input Sound File dings Take0009 Source 1 Start Time 00 00 00 00 Delete Set Start End Times input End Time D0 35 04 00 P Name Output File Dutput Sound File lt click here gt Select Estimate File Noise Estimate File lt click here gt Maximum Reduction 16 00 Threshold 14 00 Set Processing sharpness 1 00 Parameters Ba
30. In analysis and processing you may choose any combination of NoNOISE tools In some cases a single function such as Broadband Denoising will provide the desired restoration In other cases there may be multiple noise problems requiring the use of multiple NONOISE SonicStudio Version 5 1 7 Getting Started processes Many common subjects of restoration including aged phonograph records include hums rumbles scratches crackles and hiss These may require treatment with all of the major NoNOISE tools Every audio situation is unique and there is often more than one way to approach the same problem But many situations follow a common pattern and can be addressed by a common procedure Depending on the material and the results desired you may omit some processing steps or elect to change the order in which they are used 1 10 Load source materials onto the sound disks as described in the Installation and Reference manual Listen carefully to the source materials to determine the processing functions to be used Frequency Analysis may be used to identify and isolate pitched components Apply Complex Filters first to remove steady noises such as hum and turntable rumble or unpitched noises outside the range of signal Remove any large broad 10 40 millisecond audio glitches using Manual Declicking After filtering and removal of large clicks perform a click detect pass to produce a list of the
31. In cases where a clean completely free of audio signal sample of the noise floor is not available asmooth Estimate Line can be derived from just a portion of the FFT display provided that the noise in question is purely analog tape hiss L63105 1000 E RA 14200 2000 Take Noise Estimate Interpolate Estimate Fit Estimate From Gates Write Estimate 1 Place the Left and Right Gates to delineate a portion of the Estimate display that appears to be outside the range of the audio signal itself 2 Select the command Fit Estimate from Gates from the NoNOISE menu Analog tape hiss has a characteristic noise curve Fit Estimate From Gates command takes advantage of this property to produce a smooth Estimate Line from any individual section of the Estimate display Place the left and right Gates in a section of the display where signal harmonics cannot be seen The command displays a characteristic tape hiss curve using the gated region of the composite FFT 6 10 SonicStudio Version 5 Broadband Denoising Editing and Saving the Noise Estimate The Fit Estimate technique works well for recordings containing typical tape hiss but many recordings have other noise influences at work It is often necessary to sculpt the estimate manually differentiating between program signal and noise floor 21000 0 After interpolating the Estimate you can zoom in to the portion of the display where the audio signal is
32. NN 107 SCSI Slave NoNoise Processor TOP Main System Board VIEW IO Connector Board SSP 3 only a Ed 1 ho E Macintosh Rear Panel Remove SCSI terminator from Main board a b c am NuBus slots The NoNOISE co processing board is installed next to the Main board in a SCSI Slave configuration joining the SCSI connectors of each board by a common ribbon cable The onboard terminator is removed from the next to last board in the chain Note The SCSI terminator must be removed from the board at the center of the group The Sonic System will not operate properly if there is more than one terminator at the end of the SCSI bus This is referred to as double termination SonicStudio Version 5 1 5 Getting Started The NN 102 107 board is installed in the same way as the system main board For installation it is best to install the boards in a left to right sequence attaching ribbon cables to each board as it is installed to avoid running out of room to attach the cables Stereo RTDN board SCSI Slave Main System Board IO Connector Board SSP 3 gl di E m cn Li Macintosh e Remove SCSI terminator Rear Panel from Main board and first denoise board ab c NuBus slots For faster stereo processing an additional denoising board must be added This board is connected to the same SCSI bus as the main audio board and the first denoise board The board board ribbon
33. Y TO YOU IN NO EVENT WILL SONIC ITS DIRECTORS OFFICERS EMPLOYEES OR AGENTS BY LIABLE TO YOU FOR ANY CONSEQUENTIAL INCIDENTAL OR INDIRECT DAMAGES INCLUDING DAMAGES FOR LOSS OF BUSINESS PROFITS BUSINESS INTERRUPTION LOSS OF BUSINESS INFORMATION AND THE LIKE ARISING OUT OF THE USE OR INABILITY TO USE THE APPLE SOFTWARE EVEN IF SONIC HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES BECAUSE SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES THE ABOVE LIMITATIONS MAY NOT APPLY TO YOU Sonic Sonic Solutions SonicStudio the Sonic logo Audio 2000 Sonic DVD Creator DVD Production Alliance DVD Ready DVD Toolmakers Guild High Density Audio TimeTwist Varispeed MediaNet and SonicOMF are trademarks of Sonic Solutions NoNOISE is a registered trademark of Sonic Solutions Dolby Digital is a trademark of Dolby Laboratories Inc QuicKeys is a registered trademark of CE Software Inc JL Cooper is a registered trademark of J L Cooper Electronics Inc Apple the Apple logo Finder Macintosh Quadra and Quicktime are registered trademarks of Apple Computer Inc Acrobat is a trademark of Adobe Systems Inc NuBus is a trademark of Texas Instruments All other company or product names are either trademarks or registered trademarks of their respective owners Written and designed at Sonic Solutions 101 Rowland Blvd Novato CA 94945 USA Printed in the USA Sonic Part Num
34. ackle a sound file do the following 1 Select Dekrackle from the NoNOISE menu The Dekrackle Info dialog box appears and contains fields to specify the source and output sound files as well as variable parameters 2 Click to the right of the words Input Sound File in the field lt click here gt Select the source sound file from the Macintosh file select dialog box that appears 3 If needed enter Start and End Times to define the portion of the source file to be processed 4 Click to the right of the words Output Sound File to specify the name of the output sound file As indicated by the file select dialog box that appears the default name for the output file is the source file name followed by dk You may enter a different name if desired 5 If parameter settings other than the default values are to be used enter the desired values for each of the four processing parameters The default settings are suitable for a wide range of material Especially in the beginning we recommend that the default settings be used SonicStudio Version 5 5 3 Getting Started 6 Click the Launch button At the beginning of the decrackle pass the Macintosh cursor changes to the watch icon and displays for one or two minutes as the background process is placed in the Background Queue and the decrackle algorithm is loaded into the program memory of the DSPs on the NoNOISE coprocessor board Once the decrackle process has beg
35. ad below the specified Threshold are disabled Click Detect Amplitude Threshold Cancel The Threshold parameter may be changed by using the command Set Threshold from the click list editing section of the NoNOI SE menu Any change will cause some clicks to be disabled while others become enabled To view and change the Threshold parameter 1 Select Set Threshold from the NoNOISE menu 2 Click the parameter value field in the Click Detect Amplitude dialog box Drag with the mouse to select all digits or use the Tab key 3 Press the Delete key on the Macintosh keyboard 4 Enter the value desired Note that the dialog box field will accept values from 0 to 2000 but only a range of approximately 1 to 500 has a useful effect SonicStudio Version 5 4 25 Getting Started Rate Amplitude threshold may also be specified in terms of a rate of click removal When a Rate value is entered the System sorts clicks by amplitude and determines a Threshold setting that will eliminate exactly the specified number of clicks per second The effect of the Rate parameter can be seen by using the Set Rate command in the NoNOI SE menu The procedure of selecting deleting then setting the parameter are the same as in Set Threshold The implicit Threshold is indicated in two ways Click sites whose values exceed the threshold show filled in click detect bars Other sites show open unfilled detect bars The Thres
36. aks of the waveform using the good portions of the wave to reconstruct the portions that are flat topped or otherwise distorted In many cases this approach is able to restore the distorted portions enough to reduce the audible distortion significantly To use the Decrackler to remove clipping and other high level distortions 1 Load the clipped material onto the Sonic System using a reduced input level 6 10 dB This ensures that headroom exists for correction If the source audio is clipped then it is to be expected that the reconstruction will extend beyond the original top of the waveform Headroom must be above the clipping level for this reconstruction to take place 2 Run a Decrackle pass with the Amplitude Weighting parameter set high perhaps 0 7 or 0 8 and the Clip Fraction somewhat reduced 0 80 or 0 75 The range of variation in source materials and possible distortion types is huge Experimentation using a short section of the source file is recommended to determine the optimal settings for distortion removal 5 8 SonicStudio Version 5 6 Broadband Denoising Broadband noise or hiss is one of the most common forms of audio degradation Noise can be introduced from any of a number of sources including the noise floor inherent in analog tape recording and thermal noise from microphones preamps and other processing equipment To eliminate hiss and other noises it is necessary to analyze noise content and
37. ange Amplitude Weighting While Clip Fraction determines the overall percentage of samples retained unaltered in the processed output Amplitude Weighting determines how these are distributed between high and low amplitude sections of the source At the default value of 0 0 all portions of the source file are processed equally As the value of Amplitude Weighting is increased more positive the processing becomes concentrated in higher amplitude sections One can think of it as decreasing the Clip Fraction in proportion to signal amplitude Negative values may also be entered for Amplitude Weighting in which case processing is concentrated in the sections of lower amplitude The maximum range of the Amplitude Weighting parameter is from 1 0 to 1 0 In practice values less than plus or minus 0 5 are used with possibly higher values for special purposes such as distortion removal see next section SonicStudio Version 5 5 7 Getting Started NOTE As Amplitude Weighting diverges positively or negatively from zero it is recommended that the Clip Fraction be reduced by some percentage as well Otherwise there may be no processing at all in some regions of the signal Removing Peak Distortion To some extent the Decrackle function can be used to ameliorate or remove breakup and distortion associated with high signal levels By using the Amplitude Weighting factor decrackling becomes concentrated entirely in the highest pe
38. ause clicks to stand out in greater relief relative to musical program This principle can be used to create a soundfile specially for detecting clicks 3 8 SonicStudio Version 5 Manual Declicking NN 101 Segment of Complex Waveform with Synchronized Detect File Likely position of Click Sefer Kara 54 45 To create a Click Detect file 1 Place the soundfile to be declicked in an Edit Decision List EDL 2 On the Mixing Desk use a Hi Shelf or HiPass filter to emphasize clicks and glitches 3 When satisfied with the filtering follow the directions in the system User Manual to capture the output of the Mixing Desk in a new soundfile 4 Open the new soundfile in a different panel of the EDL Make sure it is synchronized with the original The clicks will be easily visible in the high pass output The typical high pass filter used to produce a Detect File for analog tape recordings or old disk recordings transferred to tape is a first order filter with high frequency of 12 000 Hz or so and Stop Ripple set at 40 dB SonicStudio Version 5 3 9 Getting Started The same high pass filter may not be appropriate to create a detect file in all circumstances One recurring situation is declicking of optical clicks occurring on old movie optical sound tracks Since the original click or dropout was band limited the resultant click does not have much high frequency energy A lower cutoff frequency
39. bar instead of the Replacement Width value Force Width Normally the same Replacement Width is applied to all enabled sites Force Click Width overrides Replacement Width for a particular site To override Replacement Width for a particular click 1 Mark the click to be forced using the left and right gates 2 Select Force Click Width from the NoNOISE menu After forcing the length of the click detect bar for that click will be used as its Replacement Width To change the width of a click site 1 Place the left and right gates around the existing site 4 28 SonicStudio Version 5 Production Declicking 2 Select Delete Click from the NoNOISE menu 3 Place the gates at the exact beginning and end points desired 4 Select Add New Click Un Force Click Width The Un Force Click Width command reverses the effect of Force Click Width Replacement Width again defines the length of reconstitute audio inserted to replace the click Storing and Closing the List Before the edited list can be used for click removal it must be stored to disk To update the click list on the Macintosh s disk 1 Select Write Click List from the NoNOISE menu Until the click list is written to disk any changes have not really taken effect and will not affect the behavior of the declicking pass The Status Window will indicate the number of clicks in the list Done With Click List When click list editing is complete you can cl
40. ber 820037A 12 96 Contents 1 SYSTEM OVERVIEW NONOISE TOOS 33 pira aaa ne 1 2 Hardware Requirements 22ceeeeeeseeeeeeeeeeennnnn 1 5 The NoNOISE Menu 1 7 A Typical NoNOISE Session unnar a 1 7 2 COMPLEX FILTERING How To Use the Complex Filters omo 2 1 Signal Analysis nennen nee an 2 2 Creating the Filter LiSt oooooooooooccoooorocrrcor rn 2 8 Applying Filters to a Sound file oooooooooorooomcooooo 2 12 Filter Types and ParameterS ooooooccoccococoooooconno 2 2 14 3 MANUAL DECLICKING NN 101 The NoNOISE Menu 000 c cece een 3 1 Interpolation Gates Command LL 3 2 Removing Clicks LL 3 3 Interpolation Algorithms 222c2ceeeeeeeeneen 3 5 Strategies for Isolating and Identifying ClickS 3 8 SonicStudio Version 5 ii NoNoise SUMIMALY is dls ran ea aaa aa 3 11 PRODUCTION DECLICKING Declick Commands rr 4 2 Processing Long Files LL 4 3 Generating the Click List ooo 4 4 ClickCorrecton iero rear 4 13 Interpreting and Editing the Click List 4 21 DECRACKLING Using the Decrackler L oc 5 2 Launching a Decrackle Pass oo 5 2 Input and Output Specification oo 5 5 Processing Parameters cece cece eens 5 5 Removing Peak Distortion 0 2 6 0000 sasssa rannan eee eee 5
41. bled gt Process ABORT Status lt disabled gt Waiting FILTER Recordings Take0006 ource filt Tilt 1 nia ila status Processing e DeQueue PutAtTop Put at Bottom Wait on Next Step esume Processes During Load While a background job is in processes you can launch additional processing jobs These are placed in the background queue and may be seen listed in the Waiting box in the Background Manager When the current job completes the system loads the next item in line for processing SonicStudio Version 5 2 13 Getting Started You can even specify the output file from a previous step as the source file for the next processing stage The Sonic system allocates file space at the time of launching so the output file s name may be chosen from the file select dialogs even though the actual sound data does not yet exist Filter Types and Parameters The filters available in the Complex Filtering module are the same as the real time filters provided for the Sonic System Extended Mixing Desk SS 201 option Some of the terms used to refer to the filter types and their variable parameters are different Center Frequency cf Band The center frequency is the reference point of the filter There are two different interpretations of the center frequency in the Sonic System Complex Filters depending on the filter type used In filters that have a ban
42. cables are connected between all three boards as shown above Installation of NONOISE cards is the same for SSP and USP cards except that the SSP 3 uses a separate I O Connector board to route SCSI to external sound storage disks while the USP uses a direct cable connection Thus USP based systems require one less NuBus slot SonicStudio Version 5 System Overview The NoNOISE Menu The NoNOI SE menu in the Sonic System s main menu bar controls all NONOISE operations Manual Declicking Create and modify Noise Estimates Complex Filtering Broadband Denoising Production Declicking and Decrackling Edit Click Lists 1 1 L NoNoise Interpolate Gates gt Restore Gates Restore Gates no display reductions Take Noise Estimate Interpolate Estimate Fit Estimate From Gates Write Estimate Read Estimate Set Filters Filter Denoise Real Time Denoise Detect Clicks Declick Dekrackle Click List Management Available commands are shown in black while commands that are inactive appear in gray A Typical NONOISE Session NoNOISE is used in many different ways In most cases the overall process remains the same Source materials are loaded onto the Sonic System sound disks where they are analyzed and processed The processed audio is assembled using the Sonic System s random access editing tools then transferred to the medium of delivery
43. ck List Editing Commands The commands for editing click lists are located in the Click List Management submenu to the NoNOISE menu Read Click List Write Click List Enable Click Enable Disable Clicks Disable Click Clear Enable Disable Set Threshold Rate Set Threshold Set Rate Force Unforce Width Force Click Width Un Force Click Width Add Delete Click i Add New Click Delete Click Store Recall List rt Close List Done With Click List The commands may be divided into groups according to function Threshold and Rate Enable Disable Common declick sources phonograph records optical soundtracks etc may contain hundreds of individual clicks It is frequently useful to limit the number of clicks actually detected and corrected For one thing the click list may grow so large as to overflow Macintosh memory producing an error Click detection uses a variable threshold to determine which clicks to mark and which to leave untouched This value may be entered either as a Rate clicks per second or directly as Threshold and may be used to throttle back the declick process 4 24 SonicStudio Version 5 Production Declicking Threshold A click is a short section of sound whose spectrum differs markedly from that of surrounding audio Generally a click contains far more high frequency energy than the adjacent signal Each candidate anomaly is assigned a value for total spectral energy Sites that re
44. clicks to be attacked by automatic declicking Edit this list if necessary Perform a background Declick pass to remove clicks and scratches Use Manual Declicking again to remove any prominent glitches missed by the Detect and Declick passes In some cases multiple Detect Declick passes may be required If any intrusive clicks or glitches remain correct these using Manual Declicking After Declicking use the Decrackling tool to remove impulsive noises too densely spaced to be attacked as individual clicks 1 8 SonicStudio Version 5 System Overview 11 Identify a short section of pure or nearly pure noise without signal Analyze this section using the Noise Estimate function then save the estimate to disk 12 Use the real time Denoising option to adjust denoising parameters interactively 13 When suitable settings are found save the settings to disk then launch background denoising to create a denoised file using the same settings The product of the process is a sound file of restored audio that you can edit mix equalize and then transfer to your medium of delivery SonicStudio Version 5 1 9 Getting Started 1 10 SonicStudio Version 5 2 Complex Filtering NoNOISE Complex Filtering can apply up to 512 separate filters in a single processing pass It operates out of real time in the background freeing up the foreground for other work Background filtering is useful fo
45. corrections directly on the source sound file maintaining a separate hidden file of the original clicks which can be used to undo any portion of the declicking An automatic declicking session proceeds as follows 1 Load source material onto the Sonic System sound disk 2 Perform a click detect pass to identify clicks and pops to be corrected Once the pass gets started you can view the results on the first part of the file and change the detection parameters if needed SonicStudio Version 5 4 1 Getting Started 3 Following click detect read the click list into the waveform display and edit the list if necessary 4 Perform a declick pass to remove the detected clicks 5 For difficult material it may be necessary to run additional detect and declick passes 6 Remove any clicks that remain using Manual Declicking Declick Commands The NoNOISE menu includes two groups of commands for Automatic Declicking Launch Detect and Declick Edit Click List NoNoise Interpolate Gates gt Restore Gates Restore Gates no display reductions Take Noise Estimate Interpolate Estimate Fit Estimate From Gates Write Estimate Read Estimate Set Filters Filter Denoise Real Time Denoise Detect Clicks Declick Dekrackle Click List Management The first two commands launch the processes of detecting and eliminating clicks The second longer group includes commands for
46. ding The system looks at the area marked by the Gates and then adjusts that to the closest power of 2 unless the option of No Padding is selected If Pad with Zeros is selected the system will add zeros to the end of the gated area to bring it up to the nearest greater power of 2 in size If you gate an area that matches a major pitch period of the signal viewed this results in an analysis that is easier to interpret The options to Grab More Data or Take Less Data cause the system to alter the area of the waveform to fit the nearest power of 2 up or down much the same as selecting a fixed Transform Size The option of No Padding causes the analysis algorithm to run much more slowly but does not produce a correspondingly more accurate result Windowing Function To produce an accurate analysis on a finite number of data points it is necessary to apply a windowing function to compensate for the effects of transition at each end of the analysis period The Sonic System provides three types of windows that are commonly used for DSP These three types Hamming Hanning and Kaiser Bessel are optimized for different aspects of the analysis DSP authorities continue to debate the relative merits of each window For the Sonic System user it is much less important which window is chosen than that some window be used If the analysis is taken with None selected under Window function the resulting analysis will continue numerous spurious
47. display You can view the results of click detection at any desired level of detail Individual clicks may be deleted or disabled skipped by click correction and additional click sites identified prior to declicking By observing the performance of click detection you can optimize the declick parameters and improve results Click Detect Bars 00 00 10 00 00 00 20 00 Click list marks are not automatically displayed on the sound file waveform display The first step in using the click list is to read in the click list To read the click list into the waveform display 1 Open the source sound file into an Edit Decision List if it is not already open 2 Click once to select the panel containing the source file SonicStudio Version 5 4 21 Getting Started 3 Select the command Read Click List from the NoNOISE menu The click list is read in and displayed as blue click detect bars over the sound waveform slightly below the top of the panel When the display is zoomed out to show larger portions of the sound file click detect bars may appear as a solid or near solid blue line Havefora with Filled Click Detect Bor Individual click sites may be examined by using the left and right gates to mark and zoom in or this can be done automatically using the Move menu s Next Click command To zoom automatically to a click site 1 Position the right gate immediately ahead of the area to be exami
48. dwidth or Q parameter the center frequency references the midpoint of the affected region Usually the center frequency is the most affected frequency of these types of filters Filter types that affect frequencies above or below a particular frequency reference the center frequency cutoff frequency as the 3 dB point from the boost or cut specified A HiShelf filter designed to give a 6 dB boost above a crossover frequency center frequency of 10 kHz would have a boost of 3 dB at 10 kHz width bw and Q Bandwidth and O are two different ways of specifying the width of the filter The width of the filter is measured from the 3 dB down points on either side of the center frequency Bandwidth represents this width in absolute Hz A bandwidth of 1000 means that the filter is 1000 Hz wide between the 3 dB points 2 14 SonicStudio Version 5 Complex Filtering Q represents the width of the filter relative to the way that we hear AQ setting of 2 always has a half octave bandwidth regardless of the center frequency In mathematical terms the Q is equal the center frequency divided by the bandwidth Q Center Frequency Bandwidth Also Bandwidth Center Frequency Q AQ of 1 a one octave filter width A Q of 2 a half octave filter width AQ of 4 a quarter octave filter width A Q of 0 5 equals a 2 octave filter width Boost Cut The boost cut represents the maximum affect of the filter on the program material Boos
49. e 1 Place the gates around the Restore Bar left by the interpolation 2 Select the Restore Gates command from the NoNOISE menu The bar disappears and the original sound again appears in the waveform Declicking operates on the original soundfile If clicks are removed from a sound segment in an edited schedule the same Restore Bars will appear anytime that sound file is opened or edited into other audio Interpolation Algorithms There are several interpolators that are available in the NONOISE System Each type is suited to a particular type of audio problem and context B Type B Type L gt R B Type L lt R D Type C Type Equal C Type L gt R C Type L lt R A Type E Type F Type The different types A B etc were designated in the order that they were developed However this is not the order of most frequent use The submenu lists the interpolation types in approximate order of the frequency of their use SonicStudio Version 5 3 5 Getting Started Note The B type interpolator is the most general The majority of declicking situations can be handled by simply choosing this first selection Type B Interpolation This is the most general purpose of the declicking algorithms and works well on complex musical waveforms for example where several signals are combined with instruments that produce non periodic waveforms such as sax strings etc The basic Type B interpolator examines t
50. e area of the crossfade that extends beyond the Gate positions The difference between these two types is that the Type C has protections built into it for certain cases for which waveform interpolation algorithm produces bad results Type A lacks these protections The Type A interpolator will always produce an interpolation but the results may not always be pleasing The C Type interpolator will sometimes fail to interpolate the signal designated If this occurs the user should try a different interpolation algorithm The variations on the basic Type C interpolator marked C Type L gt R and C Type L lt R provide control of the loading of context information into the interpolator emphasizing either the sound to the left or sound to the right of the gated sound Types D and E Interpolation These are very high order interpolation that may be used to correct problems that elude other interpolation algorithms Be warned however The process runs from about 1000 to 2500 times real time Both interpolations use 80 bit precision arithmetic to produce very high quality interpolation The Type D interpolation is only capable of replacing up to about 2 milliseconds 0 002 seconds before it runs out of memory The Type E Interpolator provides a very similar algorithm that can be used on large sections of audio If there is a particularly problematic area then Type E manual interpolation perhaps left to run overnight can help clean up s
51. e specified file can be declicked Once the declick pass is launched the declick job is placed in the Background Queue and its progress can be viewed using the Background Manager During the first section of the pass all foreground operations are suspended while the Macintosh reads the click list and saves the click sound bites to a restore file on the sound disk After that the declick job runs non intrusively to completion in the background After declicking corrected clicks are marked by red restore bars like the blue bars that indicate click sites after a click detect pass These bars appear wherever a click has actually been corrected Depending on the settings of the declick parameters not all detected clicks are may be corrected in the declicking pass In the declicked sound file correction of individual click locations may be undone by placing the left and right gates around the area to be restored to its original state The NoNOI SE menu command Restore Gates replaces the click corrected version with original audio 4 14 SonicStudio Version 5 Production Declicking Declick Options and Parameters As with click detection parameters and options are available to tailor operation of the algorithm to the program material and the operator s objectives in a particular project Launch Declick Job Sound File lt click here gt Replacement Width seconds 0 002500
52. ear the detect bars from the display by closing the list To close the list 1 Select Done With Click List This will close the open list and remove the detect bars from the waveform display If the click list has been changed at all since it was last written to disk the System prompts you to save the changed version SonicStudio Version 5 4 29 Getting Started Click List File Format The click list is stored in text form as anormal Macintosh file and users who are reasonably savvy about Macintosh operations can open this file to view and even edit its contents The click list is found in the same folder as the sound file with the name of the sound file followed by dc The Macintosh file type is set to DCLK while the creator is SYSS The click list can be opened from an ordinary word processor program by changing the file type from DCLK to TEXT If the list is changed the file type must be set back to DCLK before the file can be used for declicking Many word processors include an option to open any file no matter what the file type These can be used to open the file but the edited file cannot then be used for declicking because it is no longer of the correct type A Macintosh utility program such as CE Software s Disktop may be used to change the edited file s type and creator so that it can be used by the Sonic System The click list consists of a program in the compu
53. ed Note Be cautious about selecting Delete Input if you are not reasonably certain of the results of processing Once the input file is deleted there is no way to run additional processing runs without reloading the original file Setting the Processing Parameters The previous section covered the parameters of denoising in some detail Any value desired may be entered in the Mono NoNOISE Preferences dialog box prior to launch Typically the operator arrives at a set of parameter settings by using real time denoising These settings should be stored to disk before closing the Real Time Denoising dialog box This file of stored parameters can be read directly into the background process by clicking on the Open Params button Once source destination and Noise Estimate files have been selected and the denoising parameters set as desired it is time to launch the process Launching Background Denoising Once all the required parameters and selections have been entered the Launch button in the Mono NoNOI SE Preferences dialog box becomes active The Denoising job can be launched by clicking on this button or hitting the RETURN key on the computer keyboard 6 24 SonicStudio Version 5 Broadband Denoising The defined processing job is then placed into the Background Queue If other jobs are in progress it remains there until those jobs are finished If there are no other jobs ahead of it the denoise job is loaded di
54. emains manageable within Sonic System memory Recommended Settings For 78 RPM phonograph recordings an Initial Threshold value between 5 and 10 is recommended To detect only loud clicks use a range of 100 200 To find all clicks use the minimum setting of 1 but be aware that it is possible for the click list to become so large that it cannot be processed because of memory limitations For situations such as this you can run multiple detect declick passes with progressively lower thresholds allowing even the longest pieces to be declicked without memory overflow This also helps to maintain user control by allowing evaluation and possible modification of the results at each stage SonicStudio Version 5 4 9 Getting Started Center Width Definition Center Width is the length of the frame that the detector analyzes It represents the duration of a typical click If a click is much shorter than the Center Width the click detect bar may not be properly centered over the click If a click is longer than the Center Width the system will most likely still detect it but the site will be listed shorter than the actual click You may replace the entire length of the clicks during the click removal process by setting a wide Replacement Width setting see Declick Parameters Recommended Settings Typical clicks range from about 0 5 to 2 5 milliseconds in length We recommend keeping the Center Width within this range The ini
55. er values cause quicker attenuation as instantaneous energy falls off from the threshold value resulting in a response similar to that of a noise gate If the sharpness is too low there may be no reasonable amount of noise reduction possible despite what the other parameters are set to Generally this parameter should be set as high as possible without audible ill effects on the program A value of 1 0 is recommended for common tape hiss problems while a value of about 1 2 has been found useful for standard 78 RPM type recordings If the sharpness is too high you may hear a phasing like problem in the music sometimes described as an underwater effect The noise that remains may also become more unstable producing a rapid fluttering of the noise floor 6 20 SonicStudio Version 5 Broadband Denoising Bandwidth BW The Denoiser has been as a multiband downward expander with many individual bands Actually there is a bit more involved Denoising with each bin adjusted separately produces an unnatural sounding result In NoNOISE individual bins share information for more natural sound Bandwidth governs this process Higher values produce more sharing Impressionistically a higher value in most cases creates a more natural sounding result but with the risk of audible pumping of the residual noise floor A low value for Bandwidth eliminates the possibility of noise pumping but may sound less realistic and more muffled Ty
56. et the Start and End times with respect to the source sound file 5 Setthe Output Sound File name by clicking on lt click here gt A Mac file select dialog appears with the sound file name followed by filt as a default Select the Filter Spec file by clicking on lt click here gt A file select dialog appears You may select any valid Filter Spec file 7 Click on the Launch button 2 12 SonicStudio Version 5 Complex Filtering The dialog includes an option to delete the original file at the conclusion of the background process This facilitates multiple background jobs by conserving space on the sound disk Delete Input should not be checked unless you are confident that the results of processing will be as desired The deleted sound file cannot be recovered When you click the Launch button the defined processing job is placed into the Sonic System s background queue This is a list of tasks that the system will perform in the order in which they are entered You can monitor the progress of a filter or other background process by selecting Background Manager from the File menu s Managers item Background Queue Manager vr EMPTY Hr ABORT status Port 2 ot disabled ABORT Status Process FILTER Recordings Take0006 ourca filt 1 ABORT Status 11 done 00 09 42 04 left Process ABORT Status lt disa
57. f 100 means that only clicks that have a total energy value higher than 100 arbitrary units are interpolated It may be more intuitive for the operator to use Rate rather than Threshold A Rate of 3 0 clicks per second means that the system will calculate a Threshold setting to yield an average of 3 interpolations per second If the source file is 100 seconds long and the Rate is set to 3 the declicker will interpolate the 300 loudest clicks Recommended Settings The default value of 30 for either Rate or Threshold is a suitable starting point Rate and Threshold are different ways to set the same parameter Threshold lets you set a specific value that defines the 4 20 SonicStudio Version 5 Production Declicking amount of click energy required to trigger interpolation Using Rate makes the computer calculate a Threshold based on a some factor that may be easier for you to visualize If Threshold is set too high or Rate is too low then the declicker will not remove as many clicks as expected If Threshold is too low or Rate too high the number of interpolations increases along with processing time and the possibility of a bad interpolation Interpreting and Editing theClick List In many cases click detect will produce acceptable results without further editing or tweaking To get the best results in all cases however you should understand how to read and modify the click list as shown by the marks in the waveform
58. he audio on either side of the click to determine the context for resynthesizing audio to fill the gap In most situations this basic interpolator will produce the best results There are two variations of the command that load the context information in a particular way If for example a click occurs just prior to the beginning of the attack of a piano note the basic Type B interpolator would include part of the piano note in its resynthesis producing the impression that the piano starts a bit early In this case the B Type L gt R variation would avoid getting the piano note into the interpolation Likewise the R gt L variation might be used in an instance where a click follows immediately after a sudden change in the audio waveform Types A and C Interpolation The Type A and Type C interpolators are waveform interpolators A waveform interpolator is most useful in dealing with periodic waveforms such as brass instruments or the human voice The Type A and C interpolators take context information from six periods the distance between successive peaks in the waveform to the left and right of the area identified by the Left and Right gates 3 6 SonicStudio Version 5 Manual Declicking NN 101 Note that after interpolation the Restore Bars extend for a short distance outside the gated area This is because the waveform interpolator performs a short duration crossfade of its results back into the original sound It is th
59. hear The Sonic Mixing desk defaults the stopripple to 0 1 dB PassRipple Passripple expresses the effect of the filter on audio in the passband Passband has two interpretations in the Sonic System depending on the filter For HiPass LowPass BandPass and BandStop filters Passband represents the portion of audio that the filter is letting pass through unchanged For HighShelf LowShelf EHighShelf Extended HighShelf ELowShelf Extended LowShelf Parametric and EPara Extended Parametric filters Passband represents the portion of audio that is affected by the filter In all cases passripple is the maximum change in dB in the passband as a result of the filter A setting of 0 5 dB means that the stopband will have a maximum EQ alteration of 0 5 dB due to the filter 2 16 SonicStudio Version 5 Complex Filtering Parametric Filter The parametric presence filter boosts or attenuates a particular region of the audio spectrum Frequency Response of a Presence Filter dB boost boost 3 O de frequency dB bandwidth There are three parameters that define the response of the Parametric filter type Center Frequency cf The Center Frequency is the mid point of the band affected The Parametric filter s center frequency may be selected over a range of 1 0 Hz to 22 050 kHz Bandwidth bw The Parametric filter is a resonance type filter Its bandwidth in Hertz may be translated to filter Q
60. here and there Then the operator runs a decrackle pass as described in this chapter The Decrackler does not distinguish between pure crackle and isolated clicks It tries to eliminate both The point of running a declicking pass first is that the Decrackler has only a certain amount of processing ammunition for each frame of data If it has to spend too much getting the larger clicks out then it will not have enough left for the crackle Launching a Decrackle Pass Like Complex Filtering and Broadband Denoising the Decrackler produces a new file and leaves the original sound file untouched To start a decrackle pass the operator specifies the source file and the name of the output file to be created There are four variable parameters that can be used in the default settings recommended in the beginning or set as desired Dekrackle Info Input Sound File lt click here gt Select Source Stereo Mate lt click here gt Files and Name Start Time 00 00 00 0005 o Delete Output Files End Time TEN Input Output Sound File Clip Fraction 0 900 Set Processing Synthesis Order 75 0 Parameters Damping Factor 0 001 Amplitude Weighting 0 0000000 open Save save As Default 5 2 SonicStudio Version 5 Decrackling Decrackle has only a single command in the NoNOI SE menu located immediately under the Declick command To decr
61. hold value in the Click Detect Amplitude dialog box automatically adjusts to correspond to the specified Rate The chart below shows representative statistics for older phonograph records These provide an indication of click Rates for various contexts Degree of Difficulty Total Clicks 3 min Clicks per Second Easy 50 0 25 Average 200 1 Difficult 3 Worst 2000 11 Enable Click The Threshold Rate parameter causes various click sites to be enabled or disabled automatically You can also force the state of individual clicks To enable a click site for correction 1 Place the left and right gates on either side of the selected site 4 26 SonicStudio Version 5 Production Declicking 2 Select Enable Click from the NoNOISE menu The bar over the click site will appear as filled and the designated click will be processed regardless of the Threshold setting Disable Click Similarly you may force the declicker to ignore a particular site To disable a click site 1 Frame the click site using the left and right gates 2 Select Disable Click from the NoNOISE menu The bar over the click site now appears as open or unfilled Clear Enable Disable Enable Click and Disable Click commands force a given click site to be processed or ignored To revert to the normal condition in which the value assigned is compared to the Threshold mark the click using the left and right gates then select Clear Enable Di
62. ighShelf and ELowShelf By increasing the order of the filter the sharpness of transition between passband and stopband increases Frequency Response of High and Low Order High Shelving Filters boost boost 3 O dB frequency boost cut Fe sonon Low Order High Order The Extended Shelving filters have addition parameters for setting the order of the filter as well as ripple in the response in the pass and stopbands Filter Order n The order of a filter an integer from 1 to 4 determines the slope of the filter s response curve A first order filter has a slope of 6 dB per octave Slope increases by 6 dB per octave for each increment of 1 to the filter s order 2 20 SonicStudio Version 5 Complex Filtering PASSBAND RIPPLE passripple In a Shelving filter the passband is the portion of the signal affected boosted or cut by the filter Passripple is the maximum change in dB in the passband A setting of 0 5 dB means that a maximum EQ boost or cut in the stopband of 0 5 dB STOPBAND RIPPLE stopripple The stopband is the portion of the signal not affected by the filter High Pass and Low Pass Filters HiPass and LowPass The high pass and low pass filters operate in three regions A passband where signal is minimally altered stopband where signal is attenuated and the transition band that separates the two In the passband there is an amplitude fluctuation called passband ripple Generally a
63. ime denoise output to hard disk RTDN output is captured to an audio file by using the EDL record feature as described in the main system manual It is also possible to use real time denoising to process line input to the Sonic System by selecting L1 or L2 for the input to Desk It is highly advisable to record at least a short section of the audio source into the system so that a valid Noise Estimate may be developed It is not advisable to use a Noise Estimate taken from other similar material Seemingly small differences in the audible noised characteristic can translate into much larger differences in the output Denoise Parameters In adjusting the operation of the denoise algorithm the operator has control over a number of parameters There are slight differences in the terms used for these parameters between the Real Time and Background forms of the process The names that appear in the Background Denoise SonicStudio Version 5 6 17 Getting Started launch dialog box are generally longer and hence more complete so these are stated first with the parameter name as it appears in the real time dialog box in parenthesis Real Time Denoise Background Denoise Maximum Reduction 16 00 Sharpness 1 00 Bandwidth 1 80 Low Cutoff Freq 50 00 Thres Alten Sharp BY Cutoff High Cutoff Frequency is not available in real time denoising l Tra A a e e fe For Real Time Denoising the
64. ine the exact frequency of each component from the frequency analysis display and use this to set a corresponding filter To use the Frequency Analysis tool 1 Create or open an Edit Decision List EDL on the Sonic System 2 Open the file that you wish to process into a panel of the EDL 3 Use the left and right gates and zoom functions to zero in on the section of audio you wish to analyze Use sections of less than one second for analysis Otherwise the analysis may take an inordinate amount of time to complete For hum and noise removal it is usually best to analyze a section where the desired signal is low or absent This makes the components of the offending noise more easily visible 2 2 SonicStudio Version 5 Complex Filtering 4 From the DSP menu select Do Frequency Analysis The Macintosh cursor then switches to its spinning form At the end of processing the waveform panel changes to display the analysis of the selected signal Left and Right gates In the example above an analysis is performed on the noise between two phrases in a spoken word source The resulting analysis shows principally broadband noise with a prominent peak in the upper frequencies In the Frequency Analysis display you can use the left and right gates to zoom in and view a section of the display at a higher resolution SonicStudio Version 5 2 3 Getting Started You can place the left or right gates at the position
65. ion proceeds at somewhat less than real time speed The exact rate depends on the density of clicks and on the settings of the detect parameters and filter specification Background Queue Manager Port 1 war EMPTY Hr ABORT Status disabled Status CLICK DETECT Recordings Take0009 Source 1 Status 10 dono 02 28 03 00 left Status lt disabled gt Status lt disabled gt CLICK DETECT Recordings Take0009 Source 1 Status Processing DeQueue Put AtTop Put at Bottom Wait on Next Step essee Processes During Load The system places the detect job in the Background Queue Its progress may be monitored by opening the Background Manager File menu Managers command Background Manager or by bringing that window to the front using the Windows menu if it is already open SonicStudio Version 5 Getting Started Once the click detect process starts you can view the clicks already detected without waiting for completion of the pass This is useful in checking to see if the click detect parameters are set appropriately Dekrackle Read Click List Write Click List Enable Click To view the results click detect in the waveform display 1 Open the source sound file into an Edit List if it is not already open 2 Select the c
66. ique if needed Pad With Zeros Grab more data Take Less Data No Padding slow Transform Size EHACT Seconds Exact O64 0128 256 0512 01024 O 2048 O 4096 8192 O16384 PostScript error unde Kaiser Bessel Beta Parameter 3 545 Stop band ripple 80 0 aB Pass band ripple 0 1 aB Normalized peak width 1 516 a Transform Type The default setting for Transform Type is DFT for Discrete Fourier Transform This is the familiar type of analysis in which the results are expressed in a frequency versus amplitude format Autocorrelation analysis is the inverse of the DFT In this form the results are expressed in terms of the period of the component signals rather than frequency The full scale in which the periods are expressed equals the length of the analyzed section see below Cepstrum analysis is a more specialized form of signal analysis that is sometimes used for speech work SonicStudio Version 5 2 5 Getting Started Padding Technique and Transform Size Frequency analysis works most quickly when analyzing a group of samples whose number is a power of 2 The Transform Size provides a selection of powers of two for use The largest of these 16384 corresponds to about a third of a second at a sample rate of 48 kHz You may select one of these values but it is more usual to choose the option EXACT and then specify a method of pad
67. ise can operate on a single channel mono of audio With a second card installed RT Denoise may be used in stereo RT Denoise is set up by patching the NoNOISE processing card s to one or two channels of the Mixing Desk Setting UptheMixing Desk Realtime denoising is patched as an Insert Point within a single channel of the Desk Besides the Input Select buttons each channel has a separate Insert button at the base of the channel EI TT ETTI a i a i Ual i n i Set Insert Point SonicStudio Version 5 6 13 Getting Started When the operator clicks on this Insert button it pops up a menu of selections If one NoNOISE card is installed the available selections are X No insert or 1 1 Insert point 1 If a second card is available 2 also becomes active When an Insert Point is selected the Insert button reads the number without the initial T of the insert selected for that channel Launching Real Time Denoising The Sonic System makes full use of the NoNOISE board s to run real time denoise This means real time denoising cannot be initiated if there are current background jobs in progress The Real Time Denoise command in the NoNOISE menu becomes active NoNoise Denoise Real Time Denoise Detect Clicks Declick Dekrackle Click List Management To launch Real Time Denoising 1 Select the command Real Time Denoise from the NoNOISE menu After se
68. ist has been read in you can alter it and save it to the same or different file The ability to save filter settings is particularly useful for recurring situations such as filter settings for odd even and all harmonics of line hum SonicStudio Version 5 2 11 Getting Started Applying Filtersto aSound file After you create the Filter Specification file you can apply that list of filters to any audio data file by using the Filter command The background filter process creates a new sound file by applying a filter list file to an already existing sound file Launch Filter Job Mono Select Input File Input Sound File dings Take0006 ource 1 Set Start End Times Start Time 00 00 00 00 Delete End Time 00 28 35 00 Input Name Output File Select Filter Specification File Output Sound File click here Filter Spec File lt click here gt Cancel kaung To launch a background filter job 1 Select the command Filter from the NoNOISE menu 2 Using the file select that appears choose the audio data file you wish to process The dialog Launch Filter Job appears 3 Enter the name to be used for the output file resulting from filtering and select the Filter Specification file to be used If both channels of a stereo sound file are being processed the launch dialog shows separate sections for each channel 4 If you wish to process only a part of the file s
69. it or not If a filter spec file of this name is found in the Sonic folder from earlier releases we recommend you change the name of the file so that the operator will have the choice to use the pre filtering click detect or not To use a filter spec file as a default setting rename the file filter adc Detect Parameters The click detection parameters determine how the algorithm frames the region of a click and the preceding and following Wings that provide context information These parameters combine time based and amplitude energy based factors that are used to decide what is and is not an objectionable artifact 4 8 SonicStudio Version 5 Production Declicking Initial Threshold Definition When the detection algorithm identifies a candidate click site it measures and assigns a value for total energy This is compared against the Initial Threshold and against the energy in the Wings to determine if the site is an actual click Initial Threshold is the lowest value that is recognized as a click The Launch Click Detect dialog box accepts values from 1 to 5000 for Initial Threshold but it takes a very large click to produce a total energy value greater than 200 Higher values have the effect of excluding virtually all clicks Initial Threshold has the effect of limiting the number of clicks detected This helps to avoid detection of spurious click sites and limits the size of the click list so that it r
70. lecting this command the system will take a few moments to load the real time denoising program into the DSP processors on the denoising card s 6 14 SonicStudio Version 5 Broadband Denoising The Real Time NoNOISE Preferences dialog box then displays which provides complete control over the real time denoising process in mono or stereo Switch EOE Real Time NoNoise Preferences denoising P N Wenoising is OUT in or out Select Noise Thres Alten Sharp BW Cutoff Estimate Ha ale nn L L openParams save Est PAramelers I P Save Params Save As Default Te Ally KIEA Mie Save recall settings and Thres Atten Sharp BW Cutoff f estimates 2nd channel open Est nefile gt NOT active openParams Save Est unless Save Params Save As Default 2nd board installed This dialog box displays with two sets of control sliders and buttons even if there is only a single NONOISE card available The second set of controls is not functional unless a second EFX NoNOISE board is installed in the system When the dialog box first displays Real Time Denoising is not active so the first thing to do is 1 Click the button at the top of the dialog box labeled IN
71. mall regions As with the other interpolation algorithms Type E operates directly on the sound file and it produces restore bars to show where replacement has been performed SonicStudio Version 5 3 7 Getting Started Strategies for Isolating and Identifying Clicks Often the most difficult part of declicking a cut is to locate the clicks to interpolate The interpolators included in the NoNOISE System are very powerful but they can be used only after the clicks have been found In only a small percentage of cases are the clicks in a recording easily visible in the waveform itself One approach is to use the positions of the Gates and the Play To Gates command to get a precise fix on the location of a click Simply keep moving the Left or Right Gate and auditioning until the click is no longer audible Or use the Rock N Roll feature to scrub over the area of the click Once a small area has been identified within which the click must lie Zoom into a resolution at which the click should become visible In a recording with many clicks this approach would be impractical Also even with careful auditioning and Zooming some clicks will evade this type of search A useful technique is to use the SonicStudio s filtering to emphasize the clicks and create a Detect File to identify clicks visually Creating a Click Detect File Most clicks constitute a burst of energy across the audible spectrum and a high pass filter will c
72. n 5 1 3 Getting Started The Decrackler can also be used to correct many types of peak distortion By specifying an Amplitude Weighting factor you can direct the decrackle process to concentrate waveform reconstruction on signal peaks using undistorted sections between peaks to provide the spectral information required for reconstruction Broadband Denoising Denoising begins with analysis of the background noise to produce a Noise Estimate indicating noise level versus frequency This estimate is used to set up the denoiser specifying a threshold for downward expansion in each of over 2 000 individual frequency bins The Denoiser then analyzes the source audio and reduces gain only at those frequencies where the signal level falls below a designated threshold between signal and noise floor in that band Denoising can run in real time or as a background process The advantage of real time processing is that it provides instant feedback on parameter settings You may wish to use real time processing to determine optimal parameter settings and then use the non real time processing to create an output file 1 4 SonicStudio Version 5 System Overview Hardware Requirements All NoNOISE processing tools except Manual Declicking require one or two Sonic NoNOISE Processor Boards NONOISE works in conjunction with the either USP or SSP 3 board For SSP based systems model NN 102 is used whereas USP based system require model
73. ndwidth 1 80 Low Cutoff Freq 50 00 High Cutoff Freq 22050 00 Save and Recall Parameter Settings Save As Default toner You have the option of processing only a portion of the source file by entering Start and End Times in the designated fields Otherwise the entire file is processed 2 If needed enter Start and End Times to define the portion of the source file to be denoised Once the input soundfile s are selected it is necessary to select a Noise Estimate file and specify the name of the denoised file to be created by the process 3 Click to the right of the words Output Sound File Another file select dialog box appears with the name of the source file followed by the dn as the default name for the output file If a file by this name already exists or if another name is desired for any other reason enter the name in the dialog box and click OK SonicStudio Version 5 6 23 Getting Started 4 Click to the right of the words Noise Estimate File Once again a Mac file select appears Using this dialog box locate and open the Noise Estimate to be used Delete Input All background processes which involve the use of input files for example denoise jobs are equipped with an option to permit deletion of the input file at the conclusion of the background process This can facilitate multiple background jobs since the amount of space required on the sound disks for buffering is reduc
74. ned 2 Select the command Next Click from the Move menu This positions the display around the next click site and zooms in to a level at which the click can be easily seen Each time Next Click is selected the display moves to the next site in the list When the end of the list has been reached Next Click has no effect 4 22 SonicStudio Version 5 Production Declicking For practice both interpreting and editing click lists it may be beneficial to load one or more short sound files of typical material then run click detect passes with various parameter settings Hovefors sith Outlined Click Detect Bar Examination of the resulting click lists will provide a sense of how click detect determines which sites to include for the declick pass and the effect of the different click detect parameters As you examine the click list you may notice three things e Some of the detect bars are filled with color while others are shown only in outline form e Click detect bars are wider than the actual visible clicks in the waveform e Not all of the visible and audible clicks have been marked These features of the click list display are the direct result of the parameter settings The information gleaned from examining the list may also be used to modify the click list using the click list editing commands and to optimize the click detect and declick parameters SonicStudio Version 5 4 23 Getting Started Cli
75. neously Production Declicking Analog disc records contain far too many scratches and clicks to identify and correct by hand Production Declicking automates the process correcting hundreds or even thousands of clicks in a single pass Declicking is a two stage process First use the Click Detect tool to identify the locations of clicks and scratches with variable parameters that determine how the system will distinguish clicks and scratches from program audio This process produces a Click List that is used for actual click removal After click detection the source file waveform is displayed with colored bars to indicate click sites You may add change or remove these sites to ensure proper removal of all audio glitches Once the Click List is prepared a declick pass is performed to correct the marked areas As in the detect pass you specify the parameters that determine how the system replaces detected clicks with new audio Decrackling In many cases impulsive noises are so dense that they are no longer heard as individual clicks These high density impulses are perceived as surface scratch or crackle The Decrackling tool removes this high density impulse noise Decrackling runs as a single stage no detect pass background process that produces a new sound file leaving the original file untouched As with other NoNOISE processes the operator controls the degree and quality of decrackling applied SonicStudio Versio
76. nsform or FFT is a primary tool of analysis for NoNOISE projects The Fourier transform converts time domain information into the frequency domain where it can be used to pinpoint the center frequency of ahum component or to examine noise and signal bandwidth Manual Declicking In Manual declicking you identify audio clicks and glitches by listening then locating them precisely using the Sonic System s graphic waveform display Once a click or glitch is identified and marked you can use any one of several interpolation algorithms to resynthesize and replace damaged audio with a seamless reconstruction of the original program Manual declicking is most useful when source material contains a relatively small number of prominent clicks or glitches Complex Filtering You can attack discretely pitched and steady state noises such as hum and buzz using filtering techniques Complex filtering applies up to 512 high precision digital filters to surgically remove the fundamental and all harmonics of a contaminating noise Complex filtering can be used to clean up production dialog live concert recordings telephone conversations and other situations with complex pitched or band localized noise components 1 2 SonicStudio Version 5 System Overview The system performs the designated processing out of real time creating a new sound file as output Processing is performed in the background so that you can process and edit simulta
77. nterpolators may also be used to remove a variety of other ills such as needle thumps oxide dropouts etc 3 10 SonicStudio Version 5 Manual Declicking NN 101 In many of cases the difficulty is not so much interpolating the anomalies but finding them Dropouts can be viewed directly by zooming in tight on the waveform display For thumps a Detect File built on a low pass filter for example first order low pass at 100Hz may be useful Summary The SonicStudio s Manual Declick option provides a powerful set of tools to identify and correct clicks and other audible glitches embedded in program audio In the hands of a knowledgeable and experienced operator the Manual Declick tools can perform seeming miracles of sonic restoration SonicStudio Version 5 3 11 Getting Started 3 12 SonicStudio Version 5 4 Production Declicking Automatic Declicking detects and eliminate clicks automatically in two steps First a click detect pass reads through the sound file and produces a list with the location and description of each click This click list appears as marks on the waveform display indicating the locations and duration of each click The click list contains the sample number of every click found the width of the click in samples the strength amplitude of the click and other information used by the declicking algorithm The click list is then used to guide the declick pass The declick pass makes
78. nything less than about 0 5 dB of ripple is inaudible Passband ripple defaults to 0 1 dB There is also some variation in the stopband called stopband ripple It represents the maximum value that the filter gain attains in the stopband For a high pass filter the frequency parameter refers to the highest frequency at which the gain attains the minimum value in the passband A low pass filter has a gain of 1 0 less the pass ripple below f and falls off smoothly to stop ripple at some point above f Cutoff Frequency cf The Cutoff Frequency is the frequency at which signal level is reduced by 3 decibels The range of cutoff frequencies for both high and low pass filters is from 1 Hz to 22 05 kHz SonicStudio Version 5 2 21 Getting Started Filter Order n Filter order an integer from 1 to 4 controls the steepness of the transition from stopband to passband The transition band drops off by roughly 6 dB per octave for each unit increase in order The higher the order the greater the chance of audible ringing at the cutoff frequency Passband Ripple passripple In the Low and Highpass filter the Passband Ripple is the area that is not affected by the filter Stopband Ripple stopripple For Low and Highpass filters the Stopband Ripple is the maximum gain reached in the area after the cutoff frequency Utility Filters DC Emphasis RIAA Complex Filters includes several types of utility filters for common f
79. o process but are less likely to produce artifacts The default value of 0 030000 seconds 30 milliseconds provides a reasonable compromise between speed and accuracy The minimum and maximum Context Width depends on the settings of Replacement Order and sample rate Minimum Context Width Replacement Order 1 sample rate 44100 or 48000 Maximum Context Width f 4096 256 Replacement Or der sample rate 44100 or 48000 Recommended Settings For best results set the Context Width to at least twice the minimum value Using the maximum Replacement Order of 512 at 44 1 kHz sample rate the minimum context is about 0 012 seconds 12 milliseconds and the Context Width should be set to at least 0 024000 seconds Setting Context Width too low will produce artifacts sounding like anything from low frequency thunks to bursts of noise depending on the context Setting the Context Width too high however substantially increases processing time Note If the total of Context Width and Replacement Width is too large the system produces an error message when the declick pass is launched indicating that twidth total width gt 4096 or contextWidth lt 0 SonicStudio Version 5 4 17 Getting Started If this occurs reduce the value of either of both parameters and relaunch declicking Replacement Order Definition Replacement Order sets the precision of the re synthesis calculation and has to do with the
80. o use Replacement Center is almost never set higher than 50 percent as this would shift the interpolation forward ahead of any ringing The Replacement Center parameter can be of use in extraordinary situations For example one project at Sonic Solutions involved a record that had been broken and then glued back together resulting in clicks of SonicStudio Version 5 4 19 Getting Started about 2 5 milliseconds in duration followed by over 10 milliseconds of ringing A Replacement Width of 15 milliseconds and a centering of 20 percent turned out to be the best setting in this case Rate and Threshold Definition Rate or Threshold determines how many interpolations are actually performed out of the click sites marked in the click detect pass The Initial Threshold parameter in click detect determines which candidate sites are marked After that the Threshold Rate parameter can be used to enable and disable clicks from the list Refer to the following section on editing the Click List When a declick pass is launched you must specify a value for Threshold This value controls the action of the declick pass regardless of the value specified for the List Note Enable Disable of click sites is determined by the setting of Threshold Rate in the Launch Declick dialog box It is not affected by the setting used in editing the list Rate and Threshold limit the number of clicks actually interpolated A Threshold o
81. of increasing time or increasing amplitude or anything else Optional arguments can be in any order but the first three arguments must be given in exactly the order shown SonicStudio Version 5 4 31 Getting Started 4 32 SonicStudio Version 5 5 Decrackling Impulsive noises in recordings come in two general varieties Clicks pops ticks and spikes are sizable impulses that break the flow of audio in a way that is comparatively easy to recognize and isolate Usually such glitches are spaced far enough from one another so that the audio on either side can be used to reconstitute the area of the click The Manual and Production Declicking modules of NONOISE are effective in attacking this type of problem The other common type of impulse noise is crackle in which small impulses crowd against one another producing a nearly continuous noise like bacon frying in a pan This type of artifact requires a different processing approach The Decrackle module is effective for correcting this type of dense impulsive noise by performing a type of sliding interpolation that isolates good audio between impulses and uses it as the basis for resynthesis SonicStudio Version 5 5 1 Getting Started Using the Decrackler Usually the Decrackler is used together with Production Declicking The general procedure is to perform a light declicking pass and take out the large conspicuous clicks It is acceptable to leave a click
82. of a parameter and its effect becoming audible Raking the sliders up and down will have little or no effect By carefully adjusting these parameters especially the Threshold and Attenuation controls and listening to the results the operator can optimize the operation of broadband denoising to remove the greatest amount of objectionable noise while avoiding undesirable artifacts in the finished product The IN OUT button can also be used to compare processed versus unprocessed audio 6 16 SonicStudio Version 5 Broadband Denoising Sets of processing parameters may be saved to disk and recalled by using the Open Params and Save Params buttons The Save as Default button may be used to change the initial default settings that apply when the dialog box is first opened Parameter settings and Noise Estimates are compatible with those used in Background Denoise operations so you can read and write settings to be used for background processing This is convenient because it allows real time denoising to be used for testing Once the desired settings are set the complete processing job can be launched in the background and the results recovered at your convenience Capturing Real Time Denoise The output of the Real Time Denoise process can also be transferred directly to an output medium such as digital audio tape or captured to a new file using the Sonic System s capture and mount feature to record the output of the real t
83. of removing a click or noise consists of identifying the anomaly to be removed by placing the Left and Right Gates on either side of the problem area in the waveform display Once the section to be replaced is so identified the user selects one of the interpolation types from the Interpolate Gates menu Once the interpolation algorithm is selected the system performs a frequency and phase analysis of the audio on either side of the glitch to be removed It then synthesizes a section of audio to interpolate smoothly from the spectrum prior to the click to the spectrum following the click Removing Clicks The process of removing a click consists of identifying and marking the anomaly in the waveform display and then selecting an interpolation algorithm from the NoNOISE menu Identification 1 On the waveform display identify the location of the click or other anomaly to be removed 2 Zoom in until the area of the glitch fills a substantial part of the display 3 Place the Left and Right Gates around the area of the click Be careful to gate as narrowly as possible without leaving any part of the anomaly outside the gates 2222 r E T E 00 00 24 13 40 Re Clicks Gated prior to Interpolation SonicStudio Version 5 3 3 Getting Started Clicks scratches vary in length with most between 1 and 15 milliseconds Areas as long as 1 2 second can sometimes be interpolated with good results but
84. ommand Read Click List from the lower portion of the NoNOISE menu The click list is displayed as a series of blue marks over the waveform Interpretation and editing of these marks is described in the next section 4 6 SonicStudio Version 5 Production Declicking Click Detect Options and Parameters There are several variable parameters that determine how the algorithm identifies and characterizes a click Launch Click Detect Job 0 Sound File lt click here gt Specify optional Filter pec File Cirrus 80 Q Sonic filter adc Pre Filtering Initial Threshold 5 0 Set Processing Center Width seconds 0 001 Parameters Wing Width seconds 0 002 Save As Default Wing Weight 1 0 e Initial Threshold Wing Width Wing Weight e Center Width In addition there is a listing of a Filter Spec File that defines a filter or set of filters to be applied prior to actual detection If you select a filter file in this field an alternate algorithm is used for detecting clicks Most NONOISE operators prefer to use the default algorithm The settings of the variable parameters and the selection of filter file may be saved as a preset that may be recalled for use in other projects Modified settings also may be saved as the default so that the same settings appear whenever a detect pass is launched The Filter Spec File The operator has the option of
85. pical values to use here might be 8 little sharing 1 8 good standard setting 2 4 a lot of sharing In setting the bandwidth parameter look for the best compromise setting This depends entirely on the program material It should be high enough to retain high frequency response but low enough to avoid pumping or distortion caused by noise being modulated by the high harmonics of a signal High Frequency Cutoff Cutoff The denoise function lets signal in frequency bins above the high frequency cutoff point pass through the process untouched that is they are not processed This limits processing to frequencies below the high cutoff point This can be used in situations where noise is not objectionable above a certain frequency but in most cases this parameter is left set at 22050 Hz In extreme cases good results may be obtained by processing the upper and lower frequencies separately using different parameter values Run the audio through the denoiser twice using the low and high cutoff frequencies to define the area to be denoised SonicStudio Version 5 6 21 Getting Started Backgroun Low Frequency CutOff This parameter allows signal below the specified frequency to pass through unchanged This can be useful if noise is not objectionable below a certain frequency and you wish to leave it alone This parameter is not available in real time denoising owing to infrequency of use In Background Denoising Low
86. r removing hums and buzzes In some cases these problems may be attacked by using the real time filters on the Sonic System Mixing Desk There are three advantages to Complex Filtering Far more filters up to 512 can be applied in a single pass This is especially useful when multiple notch filters are used to remove fundamental and harmonics of a pitched noise such as hum Aggressive high order filters can be used without running out of DSP processing power Long files can be processed in the background freeing up the Sonic System for other work How To Use the Complex Filters There are two steps in using the Complex Filters 1 Enter a list of the filters and parameter settings and store this list as a file SonicStudio Version 5 2 1 Getting Started Signal Ana 2 Perform the filter pass on the source audio file This creates a new sound file that contains the processed sound You must specify both the source audio file and the file of filter settings to be used for the pass lysis To set up the filters appropriately you need information about the source audio Some of this information can be obtained by careful and informed listening but you are likely to need more precise information to set the frequency parameters as needed The Sonic System s Frequency Analysis tool provides a view of the audio signal in the frequency domain where you can isolate individual signal components You can determ
87. rectly for execution Note Background Denoising and any other background processes cannot be started while Real Time Denoising is in progress Before launching a background denoise job halt the real time process by quitting the Real Time NoNOISE dialog box or by aborting it from within the Background Manager As with other background processes that create new files the output sound file can be opened even while the denoising process is in progress Whatever portion of the file that has already been denoised will appear Additional sound may be read by updating the edit display Upon completion of the denoising job the complete output sound files become available on the sound disk SonicStudio Version 5 6 25 Getting Started 6 26 SonicStudio Version 5 Index A A type interpolation 3 6 Add Filter button 2 10 Add New Click command 4 28 4 29 Adjusting the processing pa rameters 6 16 Algorithm denoising 6 4 Amplitude weighting param eter 5 7 are 3 7 Automatic declicking 4 1 B B type interpolation 3 6 B type interpolation and low frequency 3 10 Background denoising 6 22 Background denoising pass 6 3 Background Filter Selection dialog 2 9 Background filters 2 1 Background filters using 2 12 Background manager 4 14 Background Manager com mand 2 13 Background queue 4 5 4 14 6 25 Background Queue Manager dialog illustrated 5 4 BandPass filter 2 15 BandStop filter 2 15
88. rgy value before it is subtracted from that of the candidate click site In essence it tells the system how much to value the wings in determining the validity of a click The amplitude of a detected click is lowered when the wing amplitude is subtracted from the click amplitude Lowering the Wing Weight could be thought of as decreasing the contrast between the site candidate and its wings This is useful in determining the validity of a click but can sometimes result in valid clicks being rejected Lowering Wing Weight compensates for this but increases the risk of falsely detecting sites that are not real clicks Recommended Settings Optimum settings for Wing Weight varies with program material The initial default of 1 0 Wing Weight has full effect is suitable for the greatest range of program material If the program material is more band limited than the clicks as with clicks on 78 RPM discs Wing Weight may be set to a lower value At a setting of 0 the criterion for click site identification is based strictly on the magnitude of the filtered signal This is useful when the audio material is severely band limited and the click s principal energy is out of the program s frequency range 4 12 SonicStudio Version 5 Production Declicking Click Correction Once a click list has been generated the declicking pass may be launched by using the Declick command from the NONOISE menu Select x Source Sound
89. sable The declicker thereafter treats the click site based on its energy in relation to the Threshold Rate setting Adding Deleting and Editing Clicks You can mark and add click sites to the list produced by click detection and clicks that are marked may be deleted Add New Click To add a new site to the click list 1 Position the left and right gates on either side of the area to be marked Make sure that the entire anomaly is included between the gates The declick algorithm uses the areas outside the gates as the basis for resynthesis If a portion of the click is left outside the gates correction may not be satisfactory SonicStudio Version 5 4 27 Getting Started 2 Select Add New Click from the NoNOISE menu The area marked by the gates will be added to the click list with the click enabled Delete Click Spurious click sites can easily be deleted To delete one or more click sites from the list 1 Place the gates on either side of the click or clicks 2 Select Delete Click All clicks between the gates are eliminated from the click list Replacement Width During declicking each click site is replaced The actual length of the sound replaced is defined by the Replacement Width parameter specified when the declick pass is launched You have the option overriding the Replacement Width parameter by editing the click list For each click the system can be instructed to use the width of the detect
90. screen If the results of processing are not suitable the processing job may be aborted from the Background Manager Input and Output Specification Besides selecting a source sound file you have the options of entering Start and End Times to delineate a section of the file to be decrackled The Decrackle process results in anew sound file and you must give this file a name Delete Input Option As with other processes that create a new file you have the option of instructing the system to delete the original file at the end of the process to free disk space for other purposes The operator should exercise caution in selecting this option for the very reason that it eliminates the source file making it impossible to redo the process if the results are unsuitable in any way If deletion is required we recommend that you perform test decracklings on short portions of the source file before proceeding with the complete decrackling job Processing Parameters The four variable processing parameters provide considerable control over the results of the decrackle process but the effects of these parameters are a bit difficult to describe in common audio terms We recommend that you experiment with the different parameters by decrackling short portions of a file This provides a good sense of each parameter s effect in a reasonable amount of time SonicStudio Version 5 5 5 Getting Started Clip Fraction This number affects
91. sence of signal you must correct the situation by editing the Estimate as described later on If the signal present is harmonic in nature such as a sustained note or chord or a vowel sound in the case of spoken word it is often much easier for the operator to identify the frequency components that represent the source signal among the noise 6 6 SonicStudio Version 5 Broadband Denoising Taking An Estimate Once a suitable portion of the sound file is identified it is time to take the Noise Estimate Take Noise Estimate Interpolate Estimate To take an initial Noise Estimate 1 Use the Left and Right Gates to mark the beginning and end of the sound file section from which the Noise Estimate is to be derived 2 Selectthe command Take Noise Estimate from the NoNOISE menu After processing the panel changes to show an Estimate display The processing time depends on the duration of the gated audio and the speed of the Macintosh CPU The Noise Estimate display is similar to the Frequency Analysis display that the basic Sonic System provides but with an important difference owing to the way in which the display is derived SonicStudio Version 5 6 7 Getting Started The Noise Estimate divides the area framed by the Left and Right Gates into windows of 2048 samples each An FFT analysis is performed on each of these windows and the results of the FFIs are averaged to produce a kind of composite FET
92. specifying pre filtering of the source file simply by selecting a filter spec file in the Launch Click Detect dialog box A default file named Click Detect Filter is provided in the Sonic folder SonicStudio Version 5 4 7 Getting Started Click Typical clicks and scratches are best found without using the pre filter version of click detection The major exception is large low frequency thumps The default or modified default filter will locate these types of glitches most effectively This default filter is a first order high pass filter with a 11 5 kHz cutoff Most of the energy in a click is in the high frequencies and the high pass filter produces a signal with large amplitude around the click s location Other filter files may be produced using Complex Filtering Users are free to create any filter specification desired but only high pass filters are likely to be of use in the detect process If the source material is inherently band limited you may lower the filter s roll off frequency and or raise the order steepness of the filter Generally if results are reasonable keep the filter specification The default values for the click detection and declicking process are set up to give good results in more than 80 percent of all cases Note In previous software versions the default filter spec file was named filter adc When the click detect sees a file of this name it automatically uses it whether you wish
93. strength or power of interpolation The default value for Replacement Order is 400 with a minimum value of3 and a maximum of 512 In general the larger the Replacement Order the better the interpolation but the slower the processing If either Replacement Order or Context Width are increased the processing time increases in proportion to the sum of the increase in these two numbers If Replacement Order is increased by 10 percent and Context Width by 10 percent then total processing time increases by about 20 percent Recommended Settings The default of 400 is a good value to use in most situations If low frequency artifacts thunks are experienced then the value of Replacement Order should be increased The tradeoff is that it will take longer to replace each click The default Context Width and Replacement Order have been found suitable for about 80 percent of Declicking projects For extremely large clicks Context Width may be raised to about 35 milliseconds 0 0350000 seconds and Replacement Order to 512 Note To use a large value Replacement Width and avoid artifacts increase Replacement Order Keep in mind that using a maximum Replacement Order of 512 limits Context Width at 44 1 kHz sample rate to 4096 256 512 44100 75 5 milliseconds 4 18 SonicStudio Version 5 Production Declicking Replacement Center Definition Replacement Center specifies an offset as a percentage that shifts the
94. system displays a standard Macintosh file select dialog box with the default name Estimate The operator can enter a different name if desired and or choose a different location in which to store the Noise Estimate Reading an Estimate There is also a command to read in a previously created Noise Estimate To read a previously saved Noise Estimate 1 Select Read Estimate from the NoNOI SE menu As with the Write Estimate command a Macintosh file select dialog box displays to permit you to locate and open any valid Noise Estimate file Other file types do not appear in this dialog box Reading in an Estimate can be useful when testing using Realtime Denoising or processing a short section of the source file reveals the need to modify the Estimate before committing the entire file for processing 6 12 SonicStudio Version 5 Broadband Denoising Realtime Denoising With one or two NoNOISE cards in the system the denoising algorithm can operate in real time and the operator can tweak the denoising parameters and evaluate the results instantaneously The parameter and Noise Estimate settings can be stored and used to process the file in background mode Alternately the output of the realtime denoising may be transferred directly to an output medium or to a new sound file via the Sonic System s Capture function Configuration and Launching With a single NONOISE card in the system Real Time Denoising RT Deno
95. t Cut is expressed in positive or negative decibels dB Order The order of the filter sets the slope of the filter s transition area A first order filter usually means that the filter has a transition slope of 6 dB octave Each increase in the order adds another 6 dB octave to the transition Thus a 3rd order filter would have a transition slope of 18 dB octave etc BandPass and BandStop filters require an even numbered order A second order BandPass BandStop has transition slopes of 6 dB octave and a fourth order BandPass BandStop has transition slopes of 12 dB octave StopRipple StopRipple expresses how the filter affects audio in the stopband The interpretation of Stopband and Stopripple depends on the filter type SonicStudio Version 5 2 15 Getting Started For HiPass LowPass BandPass and BandStop filters Stopband the portion of audio eliminated or attenuated Stopripple minimum attenuation in the stopband A setting of 40 dB means the signal will be at least 40 dB down in the stopband For HighShelf LowShelf EHighShelf Extended HighShelf ELowShelf Extended LowShelf Parametric and EPara Extended Parametric filters Stopband the portion of audio that is to be unaffected by the filter Stopripple the maximum change in dB as a result of the filter A setting of 0 5 dB means a maximum EQ alteration of 0 5 dB 0 5 dB EQ change is approximate minimum ripple audible by the human
96. te as a file that can be used by the denoising algorithm If the Noise Estimate file used is not representative of the noise to be removed then any type of unexpected or undesired result is possible Selecting Where to Take the Noise Estimate Once the source sound file is opened into a panel of an Edit Decision List the first step is to identify a suitable location from which to take the Noise Estimate Note The denoising algorithm depends on a constant level and spectrum in the noise floor Noise floors are seldom constant except within single pieces of recorded music and sometimes even not then 6 4 SonicStudio Version 5 Broadband Denoising It is usually necessary to derive a separate Noise Estimate for each cut or take If these are contained in a single sound file then that file should be denoised in sections so that the optimal set of estimates and parameter settings can be used for each cut Unless there is strong reason to believe that each cut in a compilation was Recorded in the same session With the same equipment At precisely the same levels Onto the same media Stored in the same way e Transferred to the same intermediate media In precisely the same way Converted to digital samples in the same way then it is advisable to take separate estimates for each cut or take When denoising stereo material it is also recommended to derive a separate Noise Estimate for each channel
97. tem from 1 Hz to 22 050 KHz Bandwidth bw Bandwidth is specified in Hertz with a range from 1 Hz to 22 kHz Filter Order n The order of a filter an integer value from 1 to 4 determines the slope of the filter s response curve A first order filter has a slope of 6 dB per octave Slope increases by 6 dB per octave for each increment of 1 to the filter s order SonicStudio Version 5 2 23 Getting Started PASSBAND RIPPLE passripple In a Shelving filter the passband is the portion of the signal affected boost or cut by the filter Passripple is the maximum variation in dB in the passband A setting of 0 5 dB means a maximum EQ alteration of 0 5 dB due to the filter STOPBAND RIPPLE stopripple The stopband is the portion of the signal not affected by the filter 2 24 SonicStudio Version 5 3 Manual Declicking NN 101 The Manual Declicking option for SonicStudio is designed to assist in removing unwanted intrusive noises such as clicks pops thumps etc By following a simple procedure you can replace such noises and discontinuities in the audio waveform with continuous audio Use the Left and Right Gates to identify a usually short area of the sound file containing an anomaly to be removed Use one of several interpolation algorithms selected from the system s NoNOISE menu The algorithm analyzes audio on either side of the anomaly Based on this context information the algori
98. ter language phon It is a series of calls to the procedure click This procedure has three required arguments with a number of optional arguments The three mandatory arguments are e Click location first sample in samples Length of the click in samples The amplitude of the click from 0 to 8191 inclusive The three optional arguments accessed by name are e forcedOn e forcedOff e forcedWidth 4 30 SonicStudio Version 5 Production Declicking Note Phon is case sensitive upper or lower names must be capitalized exactly as given If a click site is Enabled using the Enable Click command the phrase forced On 1 is placed as the fourth argument to the click procedure Similarly Disable Click annexes forcedOff 1 to the arguments Force Click Width adds forcedWidth 1 to the arguments Comments may be added to any phon statement by placing a semicolon ahead of the comment Examples of Valid Click Site Statements click 44100 50 100 One second in 50 samples wide amplitude of 100 click 44100 50 100 forcedWidth 1 Same but with replacement width forced to be exactly 50 samples click 88200 65 0 forcedOn 1 forcedWidth 1 Located two seconds in 65 samples wide no amplitude given so forcedOn is set to make sure it gets replaced Replacement width will be forced to 65 samples Click sites may be placed in any order They need not be in order
99. thm synthesizes replacement sound for the anomaly The replacement sound is substituted for the original sound and the original sound is stored in a special file called a Restore File from which it can be retrieved if need be The NoNOISE Menu The commands for removing interpolating clicks and other noises are located in the NONOISE menu in the main menu bar SonicStudio Version 5 3 1 Getting Started NoNoise R a interpolate Gates gt Restore Cli k Restore Gates estore Clicks Restore Gates no display reductions Take Noise Estimate Interpolate Estimate Fit Estimate From Gates Write Estimate Read Estimate Unless other NoNOISE options are installed the only commands active in this menu are the ones associated with Manual Declicking Interpolation Gates Command The command for removing clicks is Interpolate Gates at the very top of the menu This command has a pull left menu that lists several selections NoNoise Interpolate Gates Restore Gates piace L R Restore Gates no display reductions B Type L lt R Take Noise Estimate Type Interpolate Estimate Fit Estimate From Gates GIS reg Write Estimate x lana io Read Estimate y Set Filters Filter Denoise Real Time Denoise Detect Clicks Declick Dekrackle Click List Management SonicStudio Version 5 Manual Declicking NN 101 The process
100. tial default value is 1 millisecond For special cases the value might be set as high as 5 milliseconds If a recording contains several distinct kinds of clicks exist for example if a broken record contains loud and long clicks near a break and also has intermittent normal short clicks it is best to process the recording in two passes Perform the first pass using a large value of Center Width after declicking and removing those clicks perform another pass using a shorter value of Center Width Wing Width Definition Wings are the sections that precede and follow a candidate click site They provide the context information for recognizing a valid click The click detector calculates total spectral energy in the wings and in the site candidate then subtracts energy in the wings from that in the site candidate Click amplitude is the difference between the center and the wings 4 10 SonicStudio Version 5 Production Declicking Wing Width is the time in seconds on each side of the site candidate that is used for analysis The minimum value is 0 0001 seconds 0 1 milliseconds The maximum value of Wing Width is 2048 samples corresponding to approximately 42 7 milliseconds at 48kHz sample rate or 46 4 ms at 44 1kHz sample rate Recommended Settings The initial default value of Wing Width is 0 002 seconds 2 milliseconds When using the recommended click detect algorithm that is with no filter spec file this type of
101. to 92 0 milliseconds at 48 kHz sample rate At 44 1 kHz the maximum value is slightly higher The default value is 0 0025 seconds or 2 5 milliseconds Recommended Settings The default value of 2 5 milliseconds is reasonable for normal disk recordings The operator should always try to replace the minimum amount of sound necessary to eliminate the clicks It s generally best to replace just a little bit more than the actual length of the click A good rule is to examine the source material to determine the length of the average click then add approximately 20 percent The typical click from a 78 RPM phonograph record is 0 5 to 2 0 milliseconds making the setting of 0 0025 to 0 003 a good default Note The length of sound replaced is not related to Center Width in the click detect pass nor to the width of the bar that appears over the click site when the click list is read in See the discussion of Replacement Width in the section on editing the click list If the Replacement Width is set too low then partial clicks may be left in the audio If Replacement Width is set too high the chances of generating low frequency thunks due to memory overflow increases 4 16 SonicStudio Version 5 Production Declicking Context Width Definition Context Width is the length of audio to either side of the click that is used in re synthesis Its value is expressed in seconds Larger values of Context Width require longer time t
102. un the progress of the job may be monitored by opening the Background Queue Manager window Select it from the Managers command in the File menu Background Queue Manager Port 1 rt EMPTY ABORT status Port 2 ck disabled ABORT Status Process DEKRACKLE o c MasterMaker tmp MasterMakerBuffer SOURCE dk 1 ABORT Status 0 done 01 55 27 15 left 12 21 ABORT Status lt disabled gt ABORT Status lt disabled gt Waiting DEKRACKLE 0 c Mastermaker imp MastermMakerBuffer S0URCE dk 1 nia Status Processing DeQueue PutAtTop Put at Bottom Wait on Next Step Besame Processes During Load The Decrackle process is by far the slowest of the NoNOISE functions owing to the intensity of signal processing required to identify and correct thousands of impulses per second The processing time required is also affected by the settings of the variable parameters particularly Clip Fraction and Synthesis Order which are the basic throttles for the intensity of processing as described later on in this chapter 5 4 SonicStudio Version 5 Decrackling As with other background processes you may open the output file before completion The portion of the file that has been created so far will appear and the operator may listen to it and view the waveform on
103. unctions of DC removal pre and de emphasis and application or removal of the RIAA curve for vinyl records These filters have no variable parameters They are simply on or off No DC The No DC filter is a simple DC reject filter The No DC filter provides 1 dB of cut at 34 Hz and 3 dB of cut at 18 Hz Emphasis and De Emphasis The Emphasis filter is a 15 50 microsecond curve as defined as an option for Compact Disc masters The De Emphasis filter provides for removal of this high frequency boost from material that is previously emphasized 2 22 SonicStudio Version 5 Complex Filtering DC De Emphasis No DC De Emphasis combines this with a filter to remove the Sony F1 EIAJ digital audio adapter 15 50 microsecond emphasis curve RIAA and De RIAA The Sonic system supports RIAA and De RIAA filters The RIAA filter imposes the standard RIAA characteristic normally applied in LP mastering at the input to a disk cutting lathe The De RIAA filter removes the effect of a RIAA filter Band Pass and Band Stop Filters Band Pass and Band Stop are like putting together a high pass and a low pass filter Band Pass allows only certain frequencies to be admitted and rejects all others that are out of the range Band Stop eliminates a certain range of frequencies and passes all the rest Center Frequency cf The range of the BandPass and BandStop filter s center frequency is the same as for other filters on the Sonic sys
104. utoff parameter 6 22 Setting the processing param eters 6 24 Setting the Sharpness param eter 6 20 Setting the Threshold param eter 6 19 Setting up mixing desk 6 13 Sharpness parameter denois ing 6 20 Shelving filters 2 19 Signal analysis 2 2 Sonic folder 4 7 Start and end times 6 23 Stereo declicking 4 3 Stereo denoising 6 5 Stopripple 2 21 StopRipple filter 2 15 Synthesis Order parameter 5 4 Synthesis order parameter 5 6 T Take Less Data option 2 6 Take Noise Estimate com mand 6 4 6 7 Text file click list 4 30 Threshold 4 25 Threshold parameter denois ing 6 19 Threshold defined 4 20 Threshold settings 4 20 Thumps 3 10 4 8 5 7 Transform type 2 5 U Un force Click Width com mand 4 29 Utility filters 2 22 SonicStudio 5 V Viewing the waveform illus trated 6 9 W Waveform interpolator 3 6 Wind width 4 7 Windowing function 2 6 Wing Weight 4 7 Wing weight settings 4 12 Wing width defined 4 10 Wing width settings 4 11 Write button 2 11 Write Click List command 4 29 Write Estimate command 6 4 6 12 SonicStudio 5 User Manual l 6 SonicStudio 5
105. values for each frequency band or bin Interpolate Gates gt Restore Gates Restore Gates no display reductions Take Noise Estimate Noise Estimate Interpolate Estimate Fit Estimate From Gates Commands Write Estimate Read Estimate Set Filters Filter Denoise Launch Real Time Real Time Benpi Detect Clicks Declick Dekrackle Read Click List Write Click List Enable Etiek Disable ick Clear Enable Bisable i of A group of commands in the NoNOI SE menu is used to create process edit and store the Noise Estimate The Noise Estimate determines the result of the entire denoising process so it is important to ensure that the estimate taken is valid and represents the true noise floor of the source sound file SonicStudio Version 5 6 3 Getting Started The procedure for taking a usable Noise Estimate has several steps 1 Open the source sound file into an Edit Decision List 2 Identify a short 0 3 to about 0 5 seconds section of audio where there is only noise Use the Left and Right Gates to delineate this section 3 From the NoNOI SE menu select the command Take Noise Estimate 4 When the analysis display appears in the Edit Decision List panel select the command nterpolate Estimate to smooth the raw frequency analysis 5 If necessary edit the interpolated Noise Estimate as described later 6 Select the command Write Estimate to save the estima
106. wn Together with the Maximum Reduction parameter this provides the basic throttle that determines how aggressively denoising is applied As the Threshold value is raised more and more of the signal is processed At extremely high settings a distinctive watery sound may be heard on the audio signal If the Threshold is set too low little or no noise reduction is obtained The Threshold can be thought of as the fine line between noise and music globally raising or lowering the entire Noise Estimate curve relative to its original position Local adjustment of the threshold according to frequency bands is effected by adjusting the Noise Estimate curve The Threshold point is set somewhat arbitrarily at 6 dB Threshold settings and maximum reduction settings should generally be adjusted together for best results Typical values for this parameter range between 8 mild 16 moderately aggressive and 25 extreme SonicStudio Version 5 6 19 Getting Started Sharpness Sharp The denoising process works much like a multiband downward expander As signal level in a particular band drops the process reduces the gain in that band even further using an internal attenuation curve Sharpness Curves Amount of attenuation sharpness 2 0 0 sharpness 1 0 h 6 dB point a 0 5 when max attenuation Maximum Energy of signal at Attenuation frequency bin 7 Threshold The Sharpness parameter sets the slope of this curve High
107. y raising the value of the Synthesis Order to 100 or even 128 However raising the Synthesis Order markedly increases the amount of time required to process the soundfile Synthesis Order should generally be left at 75 unless the process is producing unacceptable numbers of artifacts Paradoxically processing artifacts tend to occur more with clean recordings that have high signal to noise ratios For relatively recent material such as tape recordings from the early 1950s it is common to 5 6 SonicStudio Version 5 Decrackling set the Clip Fraction t0 98 and the Synthesis Order to 128 For 78s from the 1930s however it is common to set the Clip Fraction to 0 75 and the Synthesis Order to 75 Damping Factor The Damping Factor affects the way that the Decrackle algorithm tracks high level transient information The higher the Damping Factor the more the process will tend to smooth transients in the source material Large transients sometimes produce low frequency thumps or thunks in the output A small amount of damping such as the default value of 0 001 will in most cases smooth the material just enough to prevent artifacts without adversely affecting transient response Although the range of the Damping Factor extends as high as 1 0 the highest value recommended for normal work is about 0 015 If Damping Factor is set too high there may be a loss of transient response and in extreme cases loss of overall dynamic r

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