Frequently Asked Questions

Computer & Software Installation

The Spectral Coherence Control® plug-in is available in AU, AAX & VST formats. It has been tested in Pro Tools, Reaper, and LogicPro X, and has been found to work with most other DAW programs, although some features may not be completely implemented.

In general, most Mac computers built since 2015 are capable of running at least 1 instantiation of SCC and usually several more, dependent on the exact configuration. The minimum configuration is roughly as follows: Dual core Intel i7 processor, 16 GB RAM, and 3.1 GHz processor clock. More processors, RAM, and higher clock speed will allow more instantiations. Mac OS versions tested include Sonoma, Ventura, Monterey, Big Sur, Catalina, Mojave, and High Sierra.

Some Mac OS updates and new OS releases alter the default permissions of some folders that previously were ‘read/write’ to ‘read only’. If you have administrator permissions on your computer you can simply change the permissions from ‘read only’ to ‘read/write’ for the directory where the Presets are saved, and this should solve the problem. If you are a user without administrator privileges, you will probably need to contact someone who does have administrator access to remedy the situation.

After performing an OS update, and for sure after an OS upgrade, some DAW programs do not rescan the plug-in folders to confirm all the plug-ins are valid and meet the AU or VST/VST3 requirements. This means that saved Projects may not open if they contain plug-ins that have not been re-validated. As a result, the user may need to use a special key sequence to tell their DAW to open the DAW program to a new project instead of the last saved Project, and/or request the DAW rescan the plug-in library to find all of the plug-ins available.

Possible Fix: Some DAWs operate differently, but if this happens in LogicProX, the first instructions upon opening up LogicProX after an OS update or upgrade are to open it while using the Control key held down to get to a place where the user can select ‘do not Launch’ the project. Then the user can disable all plug-ins and resave the last Project in use. Once the Project has been saved with plug-ins disabled, open the project again. This time check the plug-ins to confirm any and all plug-ins are scanned for whatever LogicProX wants to see…….and if so, say ‘done’ to the plug-in scan window, then insert your plug-ins and see if all is well. Hopefully so.

A number of Preset files are included with the SCC Installer and these have been prepared as good starting points for your adjustment and fine-tuning process. We recognize that there are varying audio tastes in tonal balance, clarity, and transient response for both headphone and speaker-based listening, and each person has a different preference. Given the number of preferences, there is a two part answer to this question:

Part 1: As a result of a wide range of listener preferences, the user should simply try all of the Preset files and listen for themselves to determine which Preset file provides the closest audio sound quality to their preference. Once the user has selected a ‘best like what they want to hear’ Preset,  then keep that option and begin tuning the available parameters for your SCC version until you obtain the sound quality you desire. 

Part 2: If you prefer headphone listening, the options are many and the Parameter set you end up liking most may be different than a Parameter set optimized for speaker system listening. There are many different ‘tunings’ for headphones, in the Pro Audio world as well as the consumer and audiophile worlds, so no one setting works for all headphones. The presets available have been tuned using several loudspeaker systems as well as several loudspeaker systems as well as 13 leading headphone models, using several different driver technologies, with prices ranging from about $100 US dollars to over $5000 US dollars. The developers also used both open and closed back headphones, so that the Parameter sets pre-installed will provide reasonable results for most headphone setups. The same is generally true for speaker-based listening, the user should simply try all the options to determine what works best for them. That being said, it is easy to compare the Parameter sets, one after another, so give them all a quick listen (give yourself 30 seconds to a minute of listening with each Parameter set to get used to the ‘sound’ of each Preset). Once you have tried several of the Presets, then decide which one comes closest to your liking. Once you have selected a starting Preset suite of settings, then begin adjusting the parameters that your version of SCC will allow you to change, and go back and forth between several combinations until you find one that suits your liking. We think you will be able to find just the right setting for your sound preference, but if you have questions, check out the user Blog (a work in progress as of product launch, but keep watching for it), or email us with your questions so we can help get you headed in the right direction.

Spectral Coherence Control Information

  • Spectral Coherence Control® is an audio plugin designed to give you control over the sound quality of your music, allowing you to modify and refine the subtle distortions in recordings to your liking, while keeping the music intact
  • Typical uses include restoration and/or selective adjustment of musical artifacts in 6 separate bands to obtain the sound quality you want
  • Selective adjustment allows reduction of sensory overload from unwanted recording or playback system by-products (sometimes referred to as edginess)
  • Bring desired sounds to the foreground by increasing the Coherence (Clarity) to create a more clear and distinct sound, increasing the perceived dynamics and intelligibility in the process without altering the gain
  • Reduce the Coherence and push the sounds you want to de-emphasize to the background to create a more Blended audio with reduced perceived dynamics

Before Spectral Coherence Control® was available, audio professionals typically chose from a suite of DAW tools that were originally intended for many different uses, all to good effect for their intended purposes. These tools have been useful, but they are sub-optimal for the task if you want to alter the Coherence (clarity or blendedness) of audio material.

  • Tone control utilization is often used to bring out the vocals, or any other instrumental line. It takes a fine ear, training, and typically lots of time for tuning.
  • Editing out or adjusting unwanted sounds by hand in the frequency domain is tedious and time consuming as well, and sometimes is impossible without adversely affecting the music.
  • Gating also is typically used to help isolate the various sounds in the mix, in order to make some sounds ‘pop out’. But this is a tedious process at best, and again takes lots of training and experimentation to properly implement the usual techniques.
  • With current technology, there are many artifacts that can’t easily be identified and isolated even if you could remove them by hand

Now with Spectral Coherence Control®, the next generation of mastering tools is available to let you work smarter, not harder, using a tool optimized for altering the Coherence of your audio.

  • Spectral Coherence Control® allows a reimagined workflow that is more effective, efficient, and provides results no other tool can match
  • Hear and remove, or subtly alter, the sounds you don’t like while leaving the music you do like untouched
  • Adjust the sound quality for best results on different types of playback systems, like earbuds/headphones, home speakers, or computer / Tab / iPad speakers
  • Spectral Coherence Control® can be applied to each track individually or the combined Mix
  • You can accurately and adaptively target and adjust desired or undesired artifacts, and remnants of the audio recording and playback processes, to affect the type of sound you want to hear.
  • These musical artifacts are what contribute to either sensory overload from recording or playback system by-products (some people call it harshness) or overly smooth homogenized sound that has lost its feel of presence.
  • Spectral Coherence Control® allows you to adjust the low-level musical information that defines both of these types of sound: the result is that you get to determine the type of sound that you provide for your customers – adjust it to your liking!

The audio capture and playback chain has compromises, like any other technology, even though we would like to think otherwise. Two articles in a recent issue of The Absolute Sound describe the situation very nicely. In the article ‘How Stereo Works’, one aspect of the recording side of the process, microphone technique, is captured succinctly: “In the end, recordings have ended up in most cases being kind of hybrid of spaced omnis and close-up omni microphones of individual sources, mixed in via pan-potting to make a kind of stereo that is neither fish nor fowl, surely not Blumlein but not purist spaced-omni Huygens’ Principle stereo, either”. (Robert E. Greene, The Absolute Sound, Issue 321). Given the multi-microphone technique describes nearly all of the music available, the cross-talk between microphones becomes more prominent with each added channel. Spectral Coherence Control ® has been designed to address just such types of unintended distortions, and can help you selectively reduce or remove them in 6 different frequency bands.  

Likewise, in the article ‘Audio Provenance’ in the same issue of The Absolute Sound, a non-trivial issue with the digitization of the audio signals that we all now listen to is addressed as follows: “Analog to digital converters have changed significantly, along with the development of electronic ways to manipulate virtually every aspect of sound quality and ‘correct’ for the limits of given singers and musicians. In most cases-as with analog recordings-no indications of the nature and scale of such technical “improvements” or changes in the music is provided in the literature that comes with a given recording.” (Anthony H. Cordesman, The Absolute Sound, Issue 321). It is these technical ”improvements” that have unintended side effects and consequences that, until you hear that they are missing when using Spectral Coherence Control®, you won’t know just how much they affect the sound you hear!

Amazingly enough, the answer is YES. Spectral Coherence Control ® was designed to remove the low level, sometimes nearly indistinguishable distortions, that may not have seemed obvious before. But once they are removed, you will finally get to hear all of the music you wanted to hear, and then you will easily notice what is ‘missing’, the distortion that Spectral Coherence Control® has enabled you to remove. Now you can enjoy your music without the annoyance of recording and playback system generated artifacts that resulted from different recording techniques, imperfect equipment designs, and implementations. All designs are compromises…the only question is how many were made with the equipment you listen to on a regular basis, and can you overcome them? The answer is, again, YES, with Spectral Coherence Control®. 

Most of us have grown accustomed to listening to whatever type of music we enjoy, and we may well not even notice that low level distortions are present……until we hear the music with them removed! Think about the chip in your car windshield that you saw by chance one day, maybe it had been there for a while, but you had not noticed it before. Yet once you have seen it, your eyes are always drawn to look at it until you can get it repaired. Low level audio distortion is like that. Sometimes it is barely noticeable, but when it is removed, the music becomes much more open and clear so that low level signals that were masked before now contribute to a much more lifelike reproduction and the music comes alive, and you will notice instantly when you are listening to music that has not had the benefit of SCC processing.

This effect is discussed in the article ‘The electrical cure’ in Vol. 44, No. 11, the November 2021 issue of Stereophile regarding a non-trivial issue with power system grounding and isolation. In the article Michael Fremer is explaining how he has hired some power system grounding gurus and electricians to clean up the power lines coming into his house because he has had some “annoying ground hum and other noise issues”. After quite a bit of redesign and work the results are discussed as follows: 

“Hungerford and De Vito encouraged me to use the Niagara 7000 in the “front end” to isolate the digital gear but to plug the amps directly into the wall, each into its own 20A circuit. The before/after difference was beyond anything I had imagined. All the 60Hz hum had been eliminated. Finally! The result was top-to-bottom background blackness even with an ear pressed to the tweeter (other than the slight, ever-present hiss that comes from the darTZeel NHB-18NS preamp). When the noisefloor fell away, dynamics greatly improved, and the musical presentation seemed to explode from the speakers with unusual ease, leaving it its wake just plain black. I could now play familiar records, streams, and files at far lower SPLs because I could hear farther into the sonic picture, Yet, when I cranked the music up, it was easier on the ears because there wasn’t a hint of congestion, hardening, or harshness. The improvement in transparency was immediately obvious, as was new transient delicacy and purity.” (Michael Fremer, Stereophile, November 2021). 

Spectral Coherence Control® allows you to take advantage of this same audio perception effect, remove low level distortions to then realize what the underlying music really sounds like! Spectral Coherence Control® does this selectively, by using the Reference Level adjustment, to remove unwanted low level distortions. It does so without the user having to identify the sounds before they are removed! The unwanted distortions are removed by the algorithm processing based on their audio level, and the user simply adjusts the Reference Level until as few, or as many, of the distortions have been removed as they desire. This is done by listening to what is being removed as the adjustment takes place so you have ultimate control of the resultant audio. It is these low level distortions that have unintended side effects and consequences that, until you notice that they are missing when using Spectral Coherence Control®, you won’t know just how much they affect the sound you hear!

How to use Spectral Coherence Control®

The Spectral Coherence Control® has a nice feature that allows the user to boost the gain of the processed audio by adjusting the ‘Gain’ setting found under the ‘Bypass’ and ‘Preview” buttons. The Gain is adjustable in small increments to allow the user to alter the gain applied to their liking, while maintaining the desired Spectral Coherence Control® processing sound.

These plots show the frequency domain representation of the audio signals. They are the FFT plots respectively of the unprocessed audio in the White plot (when the Preview button is not shown in Yellow), and the Spectral Coherence Control® processed audio in the Red plot, when Spectral Coherence Control® processing is engaged and the Bypass button is light gray. The Red plot shows a flat Red line when Spectral Coherence Control® processing is NOT engaged (the Bypass button is red), so it is obvious when Spectral Coherence Control® processing is On or OFF. Note that the Red plot is active when either the Spectral Coherence Control® processed ‘audio result’ is selected (the Bypass button is light gray), or when the Spectral Coherence Control® processed ‘audio removed’ is selected (the Preview button shows yellow). Further, when the Preview button shows yellow, the White plot on top of the GUI represents the audio distortion that is being either removed (when the Coherence value is positive) or the audio distortion that is being added (when Coherence value is negative), so the user can see and hear the distortion during parameter adjustment.

Like any new technology, there will be some unfamiliar parameters to get used to adjusting. However, the site contains some videos to help get you started, and once you are familiar with the user interface, from watching the videos, you can download both a QuickStart Guide and more comprehensive User Guide to fill in the fine points of tuning your audio to perfection.

Do you prefer to be in the front row at a concert where you can distinguish each instrument or do you prefer to be further back in the audience, where the sound becomes a blend of all music aspects?

Spectral Coherence Control® can make audio features clear, distinct, and ‘up-close’, with increased clarity, or blended, smooth and distant. And, you can have any combination you like, selectively in 6 Bands across the full frequency range

More Clear:

  • Like the subject in Portrait mode with your camera: you can bring out a specific highlighted sound or sounds in one or more frequency regions
  • The resultant processed sounds become more distinct, your chosen sounds are highlighted and stand out clearly from the mix

More Blended:

  • Like the background in a picture taken in Portrait mode with your camera: you can have the details of the background gently present, but not the focus of the picture, no sounds stand out apart from the others.
  • The processed sounds become less distinct, they blend together in a pleasing and gentle way.
  • To say it another way, Spectral Coherence Control® cleans excess audio artifacts to bring a front row experience to listeners, or blends the sound to allow the listener to be placed anywhere in the audience for the sound they prefer
  • Clearer audio creates a more precise sound, Blended audio creates the effect of organic gentle sound

Imagine you’re sitting in the upper balcony at a show. The music making it to your ears has bounced around, commingling, making it smooth and warm. Spectral Coherence Control® can be used to create that organic blend that some of our ears have grown to love. No sound overpowering the other, nothing stands out from anything else, just the way you want it.

This type of sound is obtained by using the “less Coherent” settings; select from all of the negative range of values for the adjustable Coherence parameter to obtain a more “Blended” sound.

Or alternatively, by highlighting certain sounds, instruments, or voices, Spectral Coherence Control® can be used to bring a front row experience to the listener, without the edginess usually associated with a more involved presentation. Individual details can be selectively brought forward, and the listener can distinguish between all the different sounds, creating audio that is lively and engaging. The listener’s attention is drawn to each aspect of sound, each in its turn as the music progresses.

This type of sound is obtained by using the “more Coherent’ processing; select from all of the positive range of values for the adjustable Coherence parameter, to obtain a more “Clear” sound.

If you like some parts of the musical spectrum more Coherent than others, Spectral Coherence Control® can do that too by selecting more Coherent processing for part of the spectrum, and less Coherent processing for the remaining parts of the spectrum…..providing the ultimate in user control, adjust the sound quality to your individual liking across the frequency range….at last!

Spectral Coherence Control® includes some very sophisticated and complex processing in the frequency domain, so there is a bit of delay the user might notice until the full SCC processing effect is realized. In general, Spectral Coherence Control® processing is initiated as soon as the plug-in is invoked, but all of the processing is not fully engaged and operational until after a processing delay of about 2 seconds.

Spectral Coherence Control® can be used as a stereo or mono plug-in. New users will find it easiest to optimize their audio when it is used for the final mix output. Additionally, with some practice users will find it works well on individual tracks and sub-mixes as well. The tuning process works best when adjusting the Global parameters for even a single track when listening to the final mix, because this lets the user determine how the sound of a selected track can be optimized to fit with the overall mix.

It is possible that the choices you have made to the parameter settings are causing less than obvious SCC processing results, so please reset the Global parameters back to the Default settings and take a listen again. If after resetting to the Default values does not change the sound you hear very much, it may be one of several items:

  1. It might be if you are using headphones that your headphone adapter plug (1/8th inch to ¼ inch or ¼ inch to 1/8th inch) is not passing the signal through coherently, so try using a different adapter plug. SCC developers found that some of the adapter plugs provided with even premium headphones cause some deterioration in the sound. We did not think that adapters would have a hard time making a good connection, and it is counterintuitive to think that such a small length of wire or connection can cause issues, but we found it made enough difference to affect our results. We noticed slow transient attacks and lack of high frequency content in most of the headphones we used for testing during product development, even after break-in hours, until we swapped out the plug adapters! Several adapter brands may work well, but the MOBOREST adapters worked well enough for us that we can recommend them to our customers, as of mid-2022. The MOBOREST adapter plugs provided quite a noticeable improvement in the sound of almost all of the headphones the developers tried it with (8 pairs, all from well-known pro-audio and audiophile manufacturers).
  2. It also might be that your headphones were not one of the target headphone sets used for the preset development and, while the Presets that come with SCC work reasonably well with most playback systems (pre-amps/amps/speakers) and headphone sets, you may want to adjust the parameters to slightly different values than what you see in the examples in the web site.

The most efficient way to fine tune your SCC parameters is to select the ‘Preview’ option in the SCC window so that you can listen to the effect your adjustments make on the distortions being removed (Coherence values positive), or added (Coherence values negative). Once you have selected the Preview option, then select the coherence value for the type of sound you want: set Coherence to the maximum Clarity (+ 12) for the clearest sound, or for the maximum Blend (- 4) for the smoothest sound. Then alter each of the parameters for which you have access one by one (some SCC versions allow fewer adjustments than other versions). If you have the SCC Master version make small adjustments in each of the parameters you have chosen by listening to the Preview, and continue adjusting until you hear the least desired program audio in each Band, but the most distortion, then continue adjusting each Band until you hear the sound you like overall with SCC engaged (not Bypassed). If you have the SCC Essentials version you can adjust the Global Parameters, so start with the Reference level adjustment to determine how much processing you want, then adjust the Separation and Resolution, and finally the Coherence, alternately until you obtain the most distortion, but least of the desirable program material when listening with the Preview button as Yellow. Once you have adjusted the parameters using the Preview button, then listen to the SCC processed result by unclicking the Preview button and listen to how the music sounds, now you will see the Bypass button as grey. Remember, if the Bypass button is RED, you are listening to the unprocessed, original, audio. When not in the Bypass mode, listen for more dynamics, a clearer sound, and a more distinct sound if you are seeking more Coherence (more Clarity), or listen for less dynamics, a smoother sound, and a less distinct sound if you are seeking less Coherence (more Blended).

We recognize that audio preferences vary widely, as well as the make-up of the playback rigs and how they were assembled. Further, any particular Preset, or variation of Preset values, will not work for all systems. That is why we provided a suite of Preset options that provides a good balance of performance across all 5 of the globally adjustable parameters to help you get started. The combination of Separation, Resolution, Reference Level, and Coherence controls allow the user to adjust the sound to their liking, given their particular sound system playback components. Some users have spent a great amount of time and money fine-tuning their systems to compensate for the vagaries and variability of recording quality across genres. Spectral Coherence Control® allows them a way to compensate for both the variations in recording quality and playback equipment so they finally can obtain the sound quality they want, without having to hunt for new cables or equipment when a new recording comes out that might exacerbate a sound system vulnerability. If you come across some music that does not match your sound quality preference…….retune your sound with SCC instead!

Spectral Coherence Control®  Licensing

Spectral Coherence Control® uses the iLok licensing system, which requires an iLok2 type license USB dongle, and at this time we do not support the iLok Cloud licensing option

Yes, a two-week trial period is available for you to try it in your environment, although an iLok2 is needed to get started.

The user can choose between a Perpetual license at product launch, while a monthly license for any of the Spectral Coherence Control® versions will be developed in the near future.