When it comes to noise reduction, for many, CEDAR is at the top of the food chain. But is it worth it? In this article, long time iZotope RX user, Korey Pereira takes the new CEDAR Audio Studio 9 for an in-depth test drive.

If you work with dialogue, there is a good chance you have used, or are at least familiar with, CEDAR’s DNS One real-time noise reduction plugin as in my experience, most dub stages use it as part of their signal chain to clean up noisy production tracks.

In December 2020, CEDAR released CEDAR Studio 9, which includes DNS One along with their full suite of other noise reduction and restoration tools.

What CEDAR Say About Studio 9

CEDAR Audio Studio 9 comes in 4 packages….

• CEDAR Studio 9 DNS - This includes both DNS One and DNS Two, and is perfect for all of your dialogue noise suppression requirements in audio post-production and elsewhere.

  • DNS One is ideal for removing motor noise from recordings, eliminating electrical interference, and helping to clean up recordings suffering from unfavourable acoustics and poor microphone locations.

  • DNS Two - In almost all cases, using DNS Two is as simple as switching on LEARN and then adjusting the attenuation to obtain the desired amount of noise reduction. If you're working with location sound recordists and studios who use DNS 2s, DNS Two will allow you to replicate their work precisely and fine-tune the audio for the best possible results.

• CEDAR Studio 9 Restore - incorporating no fewer than eight advanced algorithms - Declick, Decrackle, Auto Dehiss, Declip 2, Debuzz, Adaptive Limiter, as well as Manual Declick and Dethump - this package is ideal for all of your audio restoration needs. CEDAR Studio Restore comprises no fewer than eight advanced audio restoration algorithms…

  • Declick offers an improved impulsive noise detection and a better interpolator, designed to offer superior performance across a wider range of materials than ever before.

  • Decrackle boasts an ability to dig into the damaged signal to identify and remove all manner of ground-in and grungy crackle without damaging the wanted audio. It also removes many forms of buzz and some amplitude distortions from material ranging from cylinder recordings to current broadcasts contaminated with lighting buzz.

  • Manual Declick is for restoring the extended scratches and clicks encountered on many audio media - film, tape or disk, whether analogue or digital. Its dual algorithms, optimised for long clicks and scratches, will remove noises such as those found on optical soundtracks, as well as drop-outs and extended digital errors.

  • Dethump has been created to eliminate the extended low-frequency thumps that cannot be restored using conventional declicking processes and filters. It replaces the unwanted sound with restored low-frequency audio and is the ideal tool for removing many of the previously intractable problems associated with optical soundtracks, cylinders, 78rpm discs, and even modern recordings when, for example, microphones and stands are bumped.

  • Auto Dehiss has an advanced algorithm that has been designed to be far less susceptible to the unwanted side-effects sometimes called twittering, glugging, the 'underwater sound', and even 'space monkeys'. A manual mode is also offered for fine-tuning the results when wanted.

  • Debuzz has been designed to quickly remove all manner of buzzes and hums with fundamentals as high as 500Hz. It will track wandering tones and, unlike traditional filters, can successfully restore the audio without unwanted side-effects such as limited bandwidth or the hollow sound introduced by comb filters.

  • Declip 2 removes clipped samples and reconstructs the original signal, improving clarity, eliminating distortion, and restoring the original dynamic range of the damaged audio.

  • Adaptive Limiter employs another algorithm developed by CEDAR that constrains the peak level of the output while retaining the integrity of the input and with its advanced resampling and noise shaping capabilities, is ideal for mixing, final mastering and other creative duties.

• CEDAR Studio 9 Retouch - First seen in 2002, this product changed the face of the audio industry by introducing spectral editing to the world, Retouch remains the most effective way to deal with otherwise intractable audio problems. CEDAR invented spectral editing and they still hold the patents to it. But not content to leave things as they were, they have continued to research ways to improve it, making it faster and easier to use, able to cure a more extensive range of problems, as well as making it even more productive in a wider range of settings. Nowadays, it allows you to mark and process complex areas in its spectrogram using the types of tools commonly found in powerful photographic and image manipulation software. This makes it possible to identify all manner of sounds and noises which can then be manipulated using any of the processing tools at your disposal.

  • Match allows you to mark one of the offending sounds and then ask the machine learning algorithm in Retouch to find all of the other instances within the recording. Having identified all of the matches, you can then eliminate them using the appropriate Retouch tool.

  • Interpolation - This is the classic spectral editing mode that suppresses or removes problems seamlessly. It allows you to define an unwanted sound, remove it at the touch of a button and replace it using powerful models that analyse the surrounding audio and then rebuild what would have been there, had the noise not occurred.

  • Patch mode allows you to replace an area of audio with another of the same duration and the same range of frequencies (although not necessarily of the same frequencies). Think of this as copying the data from elsewhere in the spectrogram to the region that you initially defined.

  • Copy mode allows you to move an area of audio to another position. You can think of this as copying the data from a defined region to anywhere else in the spectrogram. Again, this tool includes a pitch shifting algorithm that takes into account the relative pitch of components within the audio selection, greatly aiding the correction of harmonically rich material and even allowing you to correct the pitches of incorrect notes within musical material.

  • Erase - This mode provides a quick and simple way to erase unwanted audio quickly and accurately and replace it with background sound calculated from the surrounding audio.

  • Volume - You may affect the amplitude of the signal within a region, and independently affect the amplitude of the signal lying outside that region. This allows you, for example, to reveal individual sounds or utterances within a file, either by amplifying the wanted sounds or by suppressing the rest of the audio, or both. By marking multiple regions simultaneously and reducing the amplitude of the 'outside' to its minimum, you can also use this to retain only the sounds or words wanted in an audio file.

    Repair - puts the AI into Spectral Repair. If you use spectral editing regularly, you already know the scenario - you mark a region and you want to affect a single sound within it, suppressing or accentuating it while leaving the background untouched. Repair uses AI to achieve precisely that.

  • Cleanse - Despite the power of Interpolation, Patching and Copying, there are times when those modes are unable to eliminate unwanted sounds quickly and efficiently. Examples of this include restoring sounds such as wanted speech in the presence of strong, but relatively short-lived background noises such as gusts of wind blowing across a microphone.

  • Cleanse mode was developed specifically to help to restore sounds such as wanted speech in the presence of strong, but relatively short-lived background noises such as gusts of wind blowing across a microphone.

  • Revert allows you to define any part of the spectrogram and return it to its original, unprocessed form. Much more powerful than stepping backwards and forwards through a list of actions, this allows the user to reinitialise any part of the audio no matter where it came in the process history, thus leaving later work untouched.

• CEDAR Studio 9 Complete - containing all eleven processes from the three CEDAR Studio 9 packages, CEDAR Studio 9 Complete is the unsurpassed plug-in suite for noise suppression and restoration.

What We Think About CEDAR Studio 9

DNS One

I have on occasion had access to CEDAR’s DNS One at dub stages I have worked in and have to say it is one of the easiest to use and, more often than not, the most effective tools for reducing unwanted broadband noise during a mix. Depending on the mixer’s workflow, DNS One can be placed on each individual dialogue track or dialogue re-assigns, or both. Unlike the hardware predecessors like the DNS 2000, with DNS One, being software, there is no limit to how many instances you can use in a session.

The traditional model of using DNS One as per the manual involves bringing all of the faders down to -24, then setting the “LEVEL” or threshold to establish the noise floor, then adjusting the faders to the desired result.

Back in 2015, with the release of Version 7, CEDAR added a ‘Learn’ button, which speeds up the process by taking the user straight to Level and Gain settings determined from moment to moment by a machine learning algorithm in the software itself. If the user disables Learn, they can then make minor tweaks to the most recent settings as desired.

Personally, I end up using the mouse to make adjustments, but using the fader-flip function on an S1 or other console can be a nice way to control your adjustments.

There are little arrows on the right of the interface that quickly let you jump all the faders to either 0 or -24. It would be really helpful to have a way to gang all the faders together when moving them up and down, perhaps with an OPTION modifier?

The Rest Of The Suite

Now that I have had a chance to dig into the rest of the CEDAR Studio 9 toolset, I wanted to share some other lesser-known modules that will prove useful for editors and mixers alike:

DNS Two

This offers a streamlined interface compared to DNS One, which can be a helpful supplement to DNS One when you are not getting the result you want when using broadband noise reduction. I have also found that as more production sound mixers are using either the hardware DNS 2 or CEDAR plugin for Sound Devices recorders on their mono mixes, it is useful to have a software version of that processor in situations where you need to match ISOs to a noise-reduced mono mix.

Auto Dehiss

Removing hiss from tracks has always been a challenge for me. CEDAR’s Auto Dehiss module handles this task with ease. While other tools and methods I have used remove the hiss, they tend to add an unnatural quality to the dialogue left behind. Somehow CEDAR manages to keep the voice sounding less filtered.

Declip 2

This has been another welcome addition to my toolset as a dialogue editor. While I still use iZotope’s De-Clip regularly, it has been helpful to have another option when De-Clip isn’t working the way I need it to.

Dethump

This offers an easy option when needing to remove thumps or bumps created from boom handling or someone bumping a mic stand or lav. While I will still often use a spectral repair tool or editing between lines to remove bumps, Dethump has been great when there are a lot of thumps in a track and not enough time to deal with them using spectral editing.

CEDAR Retouch

This is CEDAR’s spectral repair tool. Unlike iZotope, Retouch lives within an AAX window inside Pro Tools (or DAW of choice). It takes a little adjusting to get used to the interface and workflow, but once you do, not having to roundtrip every clip really does speed up the process on a day of heavy spectral repair work. While I still use iZotope for some spectral repair tasks, Retouch sounds great and overall does a better job than iZotope RX with trickier sounds that overlap with dialogue or other important elements with fewer artifacts.

To help speed up the workflow, there are a number of Hot Keys built into the interface to help you work faster.

Other Modules

In addition to the plugins discussed above, CEDAR Studio 9 also includes Declick, Decrackle, Manual Declick, Debuzz and an Adaptive Limiter. For general de-clicking and de-crackling, I personally still prefer to use iZotope RX, but if you are making your first noise reduction purchase, the CEDAR solutions work just as well.

Changes To My Workflow

As someone who has used iZotope RX Advanced extensively for years, there were a few changes I had to make when using CEDAR Studio 9.

Firstly, when using iZotope RX, I will often select multiple clips in Pro Tools and using ‘individual files’ and ‘clip by clip’ option in AudioSuite apply the same processing across a selection and keep the edits intact.

When using CEDAR as an AudioSuite plugin, in the same way, it sometimes messes with the sync of the selected files after rendering. My solution for this issue is to make a safety copy on the track below and render the process as a continuous file.

CEDAR Retouch has also been a great addition to my workflow from needing to roundtrip clips to iZotope RX. As discussed above, it is nice to be able to work with Retouch within Pro Tools. The process of auditioning and using the tools available to remove sounds does take a little getting used to, when coming from RX based workflow, but when surgically removing an unwanted incidental sound, CEDAR generally sounds better than Spectral Repair in RX.

That said, I do miss the ability to stack multiple processes on nastier tracks like in RX (e.g. Declip-Decrackle-Derustle-Dialogue Denoise).

Hearing CEDAR Studio In Action

While I highly recommend contacting your local CEDAR dealer to request a demo if you are serious about picking up CEDAR Studio, below are a few examples of the power these tools offer..

Sample 1: 

This scene was recorded in an office with loud HVAC in the background as well as a hiss, most likely self-noise from either the microphone or the recorder.

The first thing I wanted to do was remove some of the high frequency hiss in the track. The more I use CEDAR Studio, the more the Auto Dehiss has become my secret weapon. Here is what the same clip sounds like after apply audio dehiss…

Next, to tackle the HVAC broadband noise, I used CEDAR DNS One, using the suggested setting from the LEARN function.

As you can hear, this combination significantly reduced the background noise to a very manageable level with no noticeable artifacting. Add a background to the scene and it will be ready to go.

Sample 2

While the environment of this scene is quieter than the last, it does still have a bit of hiss and broadband noise I would like to remove. But, before we get to broadband noise reduction, I want to remove a few ticks. Luckily a few of them happen before his line, but one falls right in the middle of his line.

To remove the ticks, I used CEDAR Retouch. Using the color wheel logo in the bottom left of the interface, you can move through various color spectrums to help reveal the offending sound and remove it.

Next, I applied Auto Dehiss.

Then DNS One…

Sample 3

In this next clip, the gain structure was set up wrong during recording and the clip is pretty heavily distorted.

However, after an application of Declip 2, it went from toasted to usable.

It still had a bit of distortion on it, so I processed it a second time.

Sample 4

This last scene was recorded in an active cafe with both HVAC and industrial refrigerators causing a high level of background noise.

For this clip I decided to give DNS Two a go:

While DNS Two knocked down much of the broadband noise, I wanted to remove a little more of the hiss using auto dehiss.

In Conclusion

As we all know, there is no one noise reduction tool that can deal with every situation perfectly, but I can confidently say that CEDAR Studio 9 would be a welcome addition to any editor or mixer’s toolkit. At $4,999, compared to RX8 Advanced at $1,199 it is not by any means a small expense, but if you work professionally editing or mixing dialogue is worth making it onto your wish list.