Mixing & Mastering
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What is Audio Restoration? How to Fix Noise and Bad Audio
Audio restoration is how you fix technical issues with your audio files.
Itâs become an important workflow step for producers of all genres over the last few years.
But what exactly is audio restoration? How does it work and how can it improve your music production?
In this article Iâll break down everything you need to know about audio restoration and suggest five plugin bundles to fix your own audio files.
Letâs get started.
What is audio restoration?
Audio restoration is the term for software techniques that remove or repair imperfections in recorded audio.
This includes any processing meant to reduce the effect of pops, clicks, electrical noise or even clipping that arises during recording.
Audio restoration is used in music production and post production audio to solve technical issues that would otherwise require re-recording.
As a result itâs become an essential tool to help audio professionals lower costs and achieve better results.
Even so, audio restoration is a relatively new technology. It relies on state-of-the-art signal processing techniques that are still in active development.
Itâs likely that advanced audio restoration tools will continue to improve in the future, as will their broad appeal to musicians and producers.
What can audio restoration do?
In the past, you were stuck with any imperfections that might have made their way into your recordings if you didnât catch them right away.
For example, if you accidentally captured too much buzz or forgot to use a pop filter for your vocals, the problems were permanent.
This could be especially frustrating if a great take was ruined by preventable error.
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Luckily, todayâs signal processing techniques have advanced far enough that itâs possible to fix many imperfections that would have made the material unusable in the past.
Hereâs a quick overview of the various audio issues that restoration software is capable of addressing:
- Buzz and hum from instrument amplifiers
- Background noise and bleed for poor isolation
- Clicks and pops from faulty equipment
- Mouth noise, excessive breaths and sibilance in vocals
- Unwanted artifacts from the recording process
The result is that todayâs recordings sound much cleaner if audio restoration software has been used.
But audio restoration isnât just for the top-tier pros.
Access to this tech has levels the playing field for many DIY artists. After all, they may not have the means to access a studio where complex systems ensure noise-free operation and perfect isolation from the outside world.
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The 4 Best Audio Restoration Plugins
1. Izotope RX
Izotope RX is quickly becoming an industry favorite for audio restoration.
Now in its 10th edition, RX contains a huge suite of high performance tools to deal with any audio issue you can think of.
With a robust offline workflow in its standalone editor, RX gives you deep access to the raw material of your audio files.
Itâs available in multiple editions with different feature sets for casual producers, audio professionals and cinema post-production houses.
That said, the standard edition comes in at a fairly steep $399, so be prepared to open your wallet!
2. Sonnox Oxford Restore
Sonnox has a strong reputation among pro engineers with its Oxford suite of plugins.
The audio restoration bundle contains sophisticated technology to tackle a range of cleanup and repair tasks.
From surgical noise reduction with Oxford Denoiser to transparent click-smoothing with Oxford Declicker, these real time tools offer impressive results.
3. Acon Digital Restoration Suite
Aconâs Digital Restoration Suite offers a quartet of effective audio repair tools at a reasonable price.
In addition to the usual de-noisers and de-clickers youâll find dedicated hum and clipping removal that can come in handy.
4. Waves Restoration
Waves is known for their workhorse plugin library thatâs had a steady user base since the early days of VSTs.
Their bundle of audio restoration tools is still a usable choice in 2023, especially if youâre looking for an affordable option.
With real time tools to help you deal with noise, clicks, and hum, Restoration is frequently available at a deep discount.
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How to use audio restoration plugins
The workflow for each audio restoration process is unique.
In fact, depending on the type of operation youâre doing, it may be completely different with different parameters.
Even so, itâs possible to give some general recommendations that can help you get better results as youâre experimenting with each method.
Here are my five quick tips for newcomers to audio restoration:
1. Get familiar with the learn feature
One of the coolest things about modern audio restoration software is the ability to âlearnâ from existing parts of your audio.
This is especially helpful when it comes to noise reduction algorithms.
The trick is to select a portion of the audio that contains only the noise youâre trying to remove. It needs to be long enough to contain a good sample of the noise but it canât contain any of the musical material itself.
Once youâve learned the material, the algorithm has a clear profile of the noise you need to remove.
That makes it work more accurately with fewer artifacts from de-noising.
2. Ease up on the threshold
Many audio restoration modules feature a threshold control to dial in the intensity of their effect.
You may find the default settings to be higher than you might actually need for your application.
Try altering the threshold to decrease the intensity of the effect to see if you really need such a drastic setting.
You may find that less is more when it comes to some operations!
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3. Use EQ tools wisely
Some widely used audio restoration tools include frequency shaping controls as well.
In many cases, they control how the processes react to content in different frequency ranges.
Using these tools effectively can help you get more transparent results depending on the type of operation.
For example, noisy sources with a lots of trebly hiss may need greater noise reduction in the high frequencies while the lows can remain intact.
Conversely, the lows may need the most attention in cases of 60 Hz electrical hum.
Try any frequency-based tools if your issue is focused on a specific EQ range.
4. Try different modes
Some modules may offer different modes for detection or processing that produce different results.
In some cases they may be as straightforward as âlow-medium-highâ where in others you may need to decide between algorithms suited to melodic or rhythmic material, or different usage of CPU resources.
Itâs not always easy to tell which is the best option for every application, so make sure to audition a few before getting too invested in tweaking the settings.
After all, audio restoration isnât a magic bullet. To get the best results you need to make sure youâre using the right tool.
5. Donât be afraid to start over
When it comes to audio restoration, itâs easy to go too far and do more harm than good.
By the time youâve de-clicked, de-clipped, de-noised and de-essed, you may find that youâve changed the core sound a bit too much.
Unfortunately, it can be difficult to pin down exactly which step was the culprit. In that case, youâre almost better off starting from scratch than tracking down every parameter change you may have tried.
In most cases you can reproduce your work quicker than you may have thought once you find the problem.
Restorative processing
Audio restoration technology is improving every year.
If youâre not using this powerful class of plugins yet, thereâs no better time to bring them into your workflow.
Whether you need to tighten up minor imperfections or completely overhaul your tracks, audio restoration should be part of your strategy.
If youâve made it through this article, youâll have a great start when it comes to audio restoration.
Michael Hahn is an engineer and producer at Autoland and member of the swirling indie rock trio Slight.
@Michael HahnGear guides, tips, tutorials, inspiration and moreâdelivered weekly.
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