Z-Noise User Manual
Contents
1. reduction to suit your program material Step One Create a Noise Profile You must obtain a noise profile in order to effectively reduce noise A noise profile is the spectral density estimation of the noise and is used by Z Noise s noise suppression algorithms to make complex decisions as to what is a noise and should be eliminated and what is not a noise and should be left untouched Z Noise provides five methods for creating a noise profile depending the nature of your original material and your desired work methods Default profile When you start Z Noise a default white noise profile is loaded This white noise profile also loads when the Full Reset preset is chosen Factory presets Other standard noise profiles may be loaded from factory presets Learn Use the Learn mode when you have a clean sample of pure noise with no program material intruding upon the noise Those familiar with Waves X Noise will be comfortable with this process Select a section of audio at least 100ms long which contains only the noise you are trying to eliminate Be careful to avoid contaminations from your source audio such as ring outs and false attacks Click the Learn button in the Noise Profile area below the Z Noise analyzer The button will blink Learning Play the selected audio section through Z Noise Click Learn again to stop the learning process and create the noise profile which appears as a white line on the Z Noise analyzer T2. Waves Z Noise Software Audio Processor Users Guide Waves ZNoise Users Guide 1 Waves ZNoise Users Guide 2 1 Introduction Waves Z Noise is a single ended broadband noise reduction audio processor It very effectively reduces noise while preserving the highest audio quality Superficially Z Noise works like other broadband noise reduction processors which use a noise profile or noise print to differentiate valid signal from noise However Z Noise uses intelligent multi level decision algorithms to maximize noise reduction with minimum unwanted artifacts Plus Z Noise uses a more musical band spilt method for more natural results throughout the sound spectrum Z Noise is ideal for removing additive noise such as tape hiss vinyl surface damage wind air conditioner and ventilation system noise Z Noise offers several improvements including Z Noise works on the complete frequency spectrum thus high frequency hiss and low frequency rumble can be removed in the same pass It is a truly broadband noise removal tool Real time operation allows you to adjust parameters and hear the results immediately There are several new features in Z Noise which address problems unique to broadband noise reduction Extract Profile Mode Not always do you have a section of pure noise from which to create a noise profile Using the Extract Noise Profile feature you can create a noise profile from a noise sample which is contaminate
3. ands of the Noise Profile EQ The frequency of the active marker is displayed Waves ZNoise Users Guide 9 Gain Settings 30dB to 30 dB Default 0 dB Gain controls the attenuation or boost applied to the noise profile frequencies Increasing a frequency s Gain raises the threshold for that frequency causing the algorithm to reduce more noise in that spectrum Decreasing Gain lowers the threshold for that frequency resulting in less noise reduction in that frequency Q Settings 0 26 wide curve 6 5 sharp curve Default 1 0 Sets the Q of the frequency to be reduced or boosted A higher Q results in a narrower filter while a lower Q yields a wider gentler filter Resolution Optimization Controls Broadband noise reduction necessitates a balance between resolution in the time domain vs resolution in the frequency domain There s no perfect solution as diverse program material and various noise problems require unique compromises Z Noise allows you to choose between higher frequency resolution or higher time resolution or a compromise between the two thus optimizing resolution to best suit your program material Optimize Settings Punch Norm Smooth Default Norm Allows you to choose between higher frequency or time resolution Smooth sets the highest frequency resolution In the Smooth mode Z Noise provides the smoothest and finest overall noise reduction but with impaired transient quality Also this mode consumes mo
4. ating noise profiles Adaptive The Adaptive mode is used to eliminate noise that changes over time Z Noise updates the noise profile by analyzing the input signal on the fly Click the Adaptive button then play your DAW to sample the sound you want to clean Z Noise will start scanning the input audio and automatically assign a noise profile the initial noise profile will be a white noise profile or the last profile captured The noise profile appears as a white line in the Analyzer window The Adaptive mode requires about two seconds of audio throughput before it begins creating its own noise profile During this initialization period noise reduction can be less than ideal since Z Noise lacks a valid noise profile In order to get optimal results from the beginning of your sound source experiment with these techniques 1 Use the Learn mode to create a noise profile of a section of pure noise at or near the beginning of your source audio Z Noise will begin Adaptive mode noise reduction with this Learn mode noise profile then migrate to the Adaptive profile in a smooth way This way you will have effective noise reduction from the beginning of your source material plus the constantly updating noise reduction offered with the Adaptive mode 2 If no pure noise is available at the beginning of your source audio you can use the Extract Profile mode to create a noise profile from a segment containing both musical signal and noise As in the prev
5. chieve a better balance between noise reduction and signal loss degradation Waves ZNoise Users Guide 11 Displays Z Noise Analyzer The Z Noise Analyzer is the processor s main display It shows four colored spectral envelopes Red the input signal before Z Noise processing White the noise profile Yellow the profile shaping EQ curve Green the output signal after Z Noise processing In a healthy noise reduction process the green output signal line will generally fall below the red input signal line However peaks may overlap the red and green lines NR Noise Reduction Meter The Noise Reduction Meter shows the energy of noise being removed The meter indicates what is being removed from the audio signal and the view is unaffected by the setting of the Output Monitor Control switch When listening in the Difference mode the Noise Reduction Meter reflects the removed noise you are hearing Waves ZNoise Users Guide 12 4 Noise Profile Management What is a Noise Profile A Noise Profile is a representation of the noise targeted for removal shown as a frequency response plot Z Noise uses the noise profile to analyze and process input audio to remove noise which has the same characteristics as the noise profile Creating a Noise Profile Z Noise s Learn and Extract modes require analysis of a section of static noise in order to create a noise profile In the Adaptive mode no learning of a noise profile is require
6. d by program material which you wish to save Adaptive Mode You do not necessarily need to create a noise profile in order to reduce noise In the Adaptive Mode Z Noise extracts a noise profile on the fly and reduces the noise even if the profile changes over time Better transient treatment Z Noise offers improved transient handling as well as enhanced transient processing options that allow for greater noise reduction with less transients smearing Z Noise can detect and enhance transients prior to noise reduction processing then de enhance the transients after noise reduction thus allowing for more aggressive noise reduction while preserving transients Enhanced Noise profile adjustments In both the normal and adaptive modes Z Noise allows you to control the spectral nature of the noise profile In this manner you can more precisely define what is a noise and what is program material The noise profile can be equalized using a five band paragraphic EQ interface Waves ZNoise Users Guide 3 Knee control Here you adjust the angle of the knee to smooth or sharpen reduction dynamics How Does Z Noise Work Z Noise like other broadband noise reduction algorithms is essentially a multi band expander that uses a noise profile to set the threshold within each band according to the energy of noise analyzed in that band When energy in a specific band falls below the threshold the input signal is presumed to be nois
7. d as this calculation happens on the fly To create an effective noise profile locate a section of the source recording at least 100 ms containing pure noise These sections are typically found immediately before the audio begins after it ends or during a pause in speech or music If you take a sample from the end of a recording or during a pause be careful of ring out in the recording as this will compromise the noise profile To use the Learn mode press the Learn button then play the noise segment in your DAW The Learn button flashes Learning to indicate that Z Noise is creating the noise profile When you finish playing the sample press the Learn button again to stop the learning process and to complete the noise profile The spectrum of the noise profile is displayed in the Z Noise Analyzer as a white line If the source material does not have a section containing the pure noise you want to remove you can move to Extract Profile mode and create a noise profile Although this method of noise profile creation is essential when you are unable to locate a pure noise sample don t make Extract your first choice This method generally compromises noise reduction efficiency because isolating the noise from the audio is less accurate and can lead to audible artifacts Important notes The noise profile should be created from the same source recording as the material you are noise reducing with Z Noise Creating a noise profile from a differe
8. e or signal decaying into noise and the signal is attenuated in that frequency band Z Noise employs the most recent psychoacoustic research and multilevel decision algorithms to remove noise while preserving the sonic clarity of the source It performs much better than comparable DAW tools and as well as or better than more expensive hardware solutions Used wisely Z Noise reduces noise while minimizing artifacts and preserves the quality of the original recording In the case of broadband noise reduction noises are considered to be un correlated from the musical signal Z Noise will do a great job of removing tape flutter or analog hiss for example but it will not be able to reduce background voices or anything that might be interpreted as signal such as birds crickets music etc The Z Noise is a single ended noise reduction algorithm that does not require an encoded original recording Instead it learns or extracts a noise profile from the audio signal and uses this noise profile to help it to distinguish noise from audio data Z Noise s controls are similar to those of a dynamics processor Those familiar with a typical compressor expander should achieve excellent results within a few minutes of experimentation 2 Using Z Noise De noising with Z Noise is a two step process First you create a valid noise profile or signature of the noise afflicting your audio Then use Z Noise s many de noising tools to obtain the perfect noise
9. e five bands of EQ control as indicated by five numbered square markers on the noise profile plot are always visible and accessible from the Z Noise graph in the Analyzer window When you select the marker of a noise profile EQ band its parameters will appear in the EQ controls section just below the graph This allows for parametric control When selecting multiple bands the first band marker selected and active will be the one that appears in the profile EQ strip below the graph The Graph markers are numbered and color coded Band 1 red default frequency 60Hz default type is low shelf Band 2 magenta default frequency 181Hz default type is bell Band 3 blue default frequency 577Hz default type is bell Band 4 green default frequency 1702Hz default type is bell Band 5 yellow default frequency 5806Hz default type is high shelf Each band offers the following controls Band On Off Default On This determines whether the Profile EQ band is engaged or bypassed Dragging the band marker on the graph engages the frequency band A graph marker will highlight when on and dim when off Band Type low shelf notch bell high shelf Default band 1 low shelf default bands 2 4 bell default band 5 high shelf This determines the shape of the filter for each band The notch filter a bell with a very high Q is useful when removing distinct hum harmonics Frequency Settings 10 Hz 20 kHz Sets the frequency in each of the five b
10. ftovers gremlins singing robots or blips that sound like whistles or lingering oscillations These can be treated by first lengthening the Attack and or Release times Selecting a softer Knee setting can reduce artifacts as can using the Smooth optimize setting If the artifacts remain choose more moderate Threshold and Reduction settings Host Application Buffer Size Waves recommends setting the buffer size in your host application to at least 1024 samples This will prevent CPU spikes during moments of especially intense processing Very Loud Program Material Waves ZNoise Users Guide 15 Noise removal with Z Noise can result in very small level increases fractions of a dB in short transients Whereas this will not affect perceived levels it could cause a clipping problem with program material whose original levels reach 0dBFS If your source material has transients peaking at 0 we suggest lowering the level by perhaps 1dB BEFORE beginning to process to allow for these new peaks Don t Change Sample Rate For best results use the same sample rate for creating a noise profile and for noise reduction Switching between sample rates between noise profile creation and noise reduction can result in small but unwanted alterations in the noise profile and may compromise results Waves ZNoise Users Guide 16
11. he source signal by 34 702 samples Z Noise latency translates into the following time delays depending on sample rate This latency is particularly significant when the noisy track runs along with other tracks To maintain sync other tracks should be delayed by the same amount To use Z Noise in a digital audio workstation it is important that the DAW is able to compensate for the plug in s delay If this latency compensation feature is not available in your host DAW add at least 34 702 samples of silence at the end of the file and trim the start after the process is completed Some multi track host applications perform latency compensation automatically 44 1kHz 48kHz 88 2kHz 96kHz 0 787 sec 0 723 sec 0 393 sec 0 361 sec Since there is no practicable way to delay your other tracks in a live recording Z Noise is not recommended when monitoring a live event Storing and Recalling the Noise Profile Some audio host applications cannot store the noise profile data with the other plug in settings This means that saving a high level document which includes Z Noise processing such as a session song or other work may not guarantee proper saving of the associated noise profile We recommend saving setups within the WaveSystem to insure that the noise profile is safely stored Side Effects Used properly Z Noise creates minimal audible artifacts Artifacts which can occur include time aliasing artifacts sometimes referred to as le
12. his line represents the frequency content of the analyzed noise and changes its vertical position as you modify the Threshold At this point save your Z Noise setup which includes your noise profile For more on saving and recalling set ups refer to the WaveSystem section at the end of this manual If you cannot find a noise only section try using the default white noise profile or one of the other available factory presets or use the Extract Profile process described below Extract Waves ZNoise Users Guide 4 This option will enable you to create a fixed noise profile out of an audio section where no pure noise is available as you might encounter when cleaning music on vinyl disks To use this option select an audio section in which the signal is relatively quiet and whose program material contamination is representative of the rest of program Then click the Extract button The button will blink Extracting Play the selection of audio When finished click the button again to see the extracted noise profile Since Z Noise will need to create an average calculation of the non noise signal in order to construct a valid noise profile you should work with a relatively long and representative sample when using the Extract Profile mode Remember both the Learn and Extract methods are designed for recordings with stable noise backgrounds For modulating or changing background noises you should choose the Adaptive method of cre
13. ious example this noise profile will become the starting point in the Adaptive noise reduction process 3 If you don t create a noise profile prior to starting an Adaptive mode noise reduction process Z Noise will default to a white noise profile until it has accurately created an Adaptive noise profile After about two seconds it will shift to its new noise profile Waves ZNoise Users Guide 5 To reset the noise profile go to the load menu and load the Reset preset either Both or just Profile It is important to create a noise profile and perform noise reduction at the same sample rate Doing otherwise can result in less accurate noise reduction Step Two Noise Reduction Once you have created a noise profile of your audio you are ready to remove the noise Z Noise uses two primary parameters Threshold and Reduction to control the noise reduction process Adjust these controls first to quickly configure Z Noise for a given input signal Attack Release Transients Knee Optimize and Profile EQ parameters offer more detailed control and are described later Threshold sets a global offset for the noise profile Here you set a level used to begin distinguishing between the source sound and the noise Setting the Threshold to a high setting such as 10 dB means that the noise profile is offset upwards by 10dB resulting in more signal subject to removal Reduction Use the Reduction control to set the amount of noise reduction app
14. lied to signals falling below the threshold Increasing the Reduction setting increases the amount of noise removed from below the noise profile If time aliasing artifacts singing or robot like sounds appear decrease the Reduction setting or lower the Threshold to several dB above the background noise Artifacts are often an indication that program material is being processed along with noise Lowering the Threshold setting protects the program material from unnecessary processing Artifacts can be further minimized by adjusting the Attack Release Optimize Knee Transients and EQ parameters see the Controls section for more details For a complete user interface reference see Controls and Displays later in this manual Step Three Monitoring A useful Z Noise feature is the ability to monitor either the de noised Audio output or the Difference the noise signal being removed by Z Noise Listen carefully to the Difference signal to determine whether your settings are removing parts of the original audio signal in addition to the noise If you hear elements of the original signal in the Difference monitor mode you are likely degrading the Waves ZNoise Users Guide 6 audio signal The goal is to maximize noise reduction while affecting as little of the original program material as possible In addition to the Threshold and Reduction controls there are several tools you can use to find the best set of parameters for your program mate
15. nt source will not help Z Noise recognize the noise in your source However if you cannot find a noise only segment in your source but can find one from the same recording session under the same conditions you can use it instead and obtain good results Note that when cleaning previously released material such as vinyl albums or audiocassettes the noise in pauses between songs is not necessarily representative of the noise of the recordings At this point we recommend saving your Z Noise setup which includes the noise profile Waves ZNoise Users Guide 13 Saving Loading and Sharing Noise Profiles The WaveSystem includes a Save button that stores the noise profile in the setup file along with other parameter data Each Z Noise setup file has two spaces available for noise profiles allowing analysis and storage of two segments of noise which can be easily compared to see which works best After creating a noise profile an asterisk indicates that the setup has been modified in the Setup A B name bar This noise profile can be saved into a new setup or over the current one A noise profile can be loaded from any previously saved setup from the Load menu This can be useful if you need to process other sessions from the same recording conditions Waves ZNoise Users Guide 14 5 Important information and Useful Tips Latency To properly perform its task Z Noise must look ahead to into the future It manages this incredible feat by delaying t
16. re CPU power and may not be suitable for slower computers This mode is best used for voice and other sources without sharp attacks Punch sets the best time resolution and is recommended for materials that have significant attacks and transients such as percussive sounds or plucked strings Piano recordings are usually best noise reduced when optimized for better Punch Norm offers a nice compromise for many situations with better transients than in Smooth and better frequency resolution than in Punch Waves recommends creating a noise profile and processing the sound source with the same resolution optimization although it is possible to change resolution between these actions Noise Profile Creation Controls The Noise Profile is a fingerprint of the noise It is an essential element of effective noise reduction as this is what enables Z Noise to classify audio as noise or signal in a specific recording Z Noise offers three ways to profile noise Waves ZNoise Users Guide 10 Learn Extract and Adaptive modes Learn Best results are obtained when the noise is static and you use a small segment of pure noise from your source audio Use the Learn function with a selection consisting of only the background noise you want to remove Click the Learn button to begin the process the button changes to Learning and blinks until it is clicked again Learn assumes the input is pure noise and profiles it with no modifications Extrac
17. rial These controls will be discussed in the next section Waves recommends monitoring with headphones and alternating between Audio and Difference monitor modes several times until the right set of parameters is found Heavily damaged recordings may require compromise between audio quality and noise reduction Waves ZNoise Users Guide 7 3 Controls and Displays Controls The two fundamental noise reduction controls are Threshold and Reduction Threshold Settings 20 to 50 dB Default 0 dB This is the reference gain setting as compared to the noise profile Signal below the noise profile is cleaned while the signal above the profile is ignored or minimally processed Reduction Settings 0 100 Default 0 Determines the amount of noise reduction applied to the signal below the Threshold The higher the setting the greater the noise reduction Dynamics Controls Attack Settings 0 01 1000ms Default 0 01ms Attack is the time it takes for attenuation to stop or for the gain to rise Noise reduction is smoothly decreased to avoid pops and clicks from abrupt processing changes The default setting 0 03 second works well in most cases Explosive sounds may require a shorter time sounds that evolve more slowly may require a longer Attack time Release Settings 0 01 5000ms Default 0 40 ms Sets the time it will take for noise reduction or gain attenuation to occur or to reach its target reduction value Higher Release
18. t If your program material doesn t have a section with pure background noise find a section that is mostly noise and use Extract in the same way you used the Learn button to create a noise profile Extract assumes the input includes some noise and some signal It uses advanced intelligent algorithms to extract a noise profile from a section of audio that does not have a pure noise segment from which to learn a profile It is important to emphasize that no noise reduction occurs while creating the noise profile in the Learn or Extract modes Adaptive Both the Learn and Extract modes of noise profile creation assume that your noise is steady state i e it does not vary in character over time There are however times when Z Noise must react to an ever changing noise profile In these difficult circumstances Z Noise s unique on the fly Adaptive mode is vital In this mode Z noise will use the most recently learned or extracted noise profile as a starting point in noise reduction If no profile was learned extracted the starting point will be a white noise profile Output Monitor Control The Output Monitor switches between Audio the audio after Z Noise processing and Difference the noise being removed with the selected settings Audio is the default setting Use the Difference monitor setting to hear the noise being removed from the source signal If you hear program material within the Difference signal modify your settings to a
19. values will result in slower attenuation these settings will tend to sound smoother but will likely let more noise through than will short values Short Release values are usually more effective in removing noise but may result in an edgier sound Transients Settings 0 dB off to 15 dB Default 0 1dB Transient control is a unique feature of Z Noise which preserves transients by enhancing them before the noise reduction process takes place This enables you to increase the Threshold without compromising transients When noise reduction is completed the transients are de enhanced Note that you may need to re adjust the Threshold control when increasing the Transient settings Knee Settings 0 Hard 100 Soft Default 25 The Knee control adjusts the sharpness of the gain reduction curve below the noise profile With a hard knee setting the dynamics will activate when energy Waves ZNoise Users Guide 8 passes the threshold With softer knee dynamics will begin to activate as energy approaches the threshold Noise Profile EQ Controls The Noise Profile EQ section lets you manipulate the noise profile using a five band paragraphic equalizer This allows you to control the amount of noise reduction in different frequency ranges Its effect is similar to that of the Threshold slider except that it is frequency dependent Noise Profile EQ Parameters The Profile EQ allows you to change the frequency characteristics of your noise profile Th
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