How to Enhance Audio Recording Quality – Audio Restoration and Clean-up Tools

how to enhance audio recordingThis article will cover the topic of how to enhance audio recording quality in the studio, and audio restoration tools to use when we have bad recordings to deal with.

There are a couple of software options that I recommend later in this post, namely ERA Bundle by Accusonus and iZotope’s RX plugin, which are quite different plugins that offer great solutions for cleaning up and restoring audio.

Depending on what you’re looking for, one out these plugins will offer the best solution for you.

To learn about them, you can skip to the second half of the post.

Otherwise, let’s dig into the topic more in depth. We’ll discuss the problem areas that lead to the need of restoring audio, some preventative measures, and then get into the plugins to use.


Table of Contents


A poor quality recording can dramatically affect the final sound of your song, voiceover or podcast.

What might seem like an inoffensive hiss can soon become a major headache when mixing your audio.

In that case, we turn to audio restoration, which is a form of audio enhancement in audio production, where we clean up audio files to make them suitable for use.

What is audio restoration?

Audio restoration is the process of turning damaged audio, or audio with noises like crackles, hums and other imperfections into a listenable track.

Imagine recording the best vocal performance in your home studio, or doing a podcast or voice over, (the sort you know you can’t repeat) only to later realize it’s been ruined by endless clipping, hums, background noise and popping.

Audio restoration, usually by software plugins in a DAW or a stand-alone app, can be applied to instruments, vocals and dialogue to leave you with a desirable end product.

So no matter what you’re recording, there are numerous ways to improve sound quality.

But first, we want to deal with the source of the issue.


Preventative Medicine – Your Audio Source

Target the source of the problem. This is often your gear or the room you’re recording in.

Before you record anything, check every piece of kit you’re going to use for faults. This means testing your microphone, cable, jack and audio interface for issues. If you’re hearing snaps, crackles or pops – you may need to invest in better equipment.

Studio Cables

Believe it or not, a crackling cable doesn’t always need to be thrown in the trash. Unscrew the jacks on either end. They might be full to the brim with dust and grime from years of handling. Remove this with a dry cloth and some compressed air and try the cables again. Still no luck? Then you need some high quality studio cables.

Microphones

Microphones can break or go bad over time. They can only take so many accidental drops and bumps before they throw in the towel.

Often the small diaphragm or wire in the head of the microphone is the only thing damaged. If you’re brave enough, carefully unscrew the head and take a closer look.

If there is obvious damage, then take it to a repair shop – you shouldn’t attempt to fix microphones without specialist equipment or knowledge.

If you know you need a new microphone, then take a look at some of the most recommended ones by studio engineers.

Your Room

It’s generally recommended to record in a ‘dry’ environment.

Dry is an industry term meaning recording without any ‘wet’ sounds like echo or reverb. Too much of these will make for sloppy audio that sounds like it’s been recorded in a tiled bathroom. You can always add effects like reverb later, but they can be tricky to get rid of.

The drier an audio track is, the easier it is to mix.

If you have no choice but to record in an echoey room, consider buying some acoustic foam panels. These are foam tiles that absorb any sound before it can bounce off a wall or ceiling, creating an echo. Even if you think you’re room’s excellent for recording, take a look at every professional studio – they all have acoustic foam on at least one wall. Some completely cover the room in foam.

Why not go one step further and look into buying some bass traps? They’re also foam panels but they’re designed to absorb low-frequency sounds in the corners of rooms. If you record bass or drums live in a room, they can come in handy especially.

The two types of bass trap, porous absorbers and resonance absorbers both prevent excess echo from bleeding into your microphones. Properly placed, the right bass traps can really help.

Signal Level

Clipping is a major no-no when it comes to getting a good audio signal. And outside of a couple of the software options I’ll mention, they’re practically impossible to remove.

When you record into an audio interface or mixing board, the signal level needs to be just right, with just enough headroom.

Too quiet and you won’t be recording enough ‘information’ to make a good audio track.

But record too loud and some of the audio signal is literally cut off; this is clipping. Before you hit record, test the signal level by recording a short segment of sound. Look at your levels, if you’re going into the reds, there’s clipping and all you need to do to fix this is turn the audio level down a few notches.

You can read more about audio clipping from this blog post.

Vocal Noises

Have you ever heard a recording and felt a shudder down your spine every time the vocalist says the letter P?

This pesky letter is responsible for some terrible quality recordings. They are called “plosives.”

When you say the letter P, you push air (and some spit) out of your mouth at high speed. This suddenly jolts the microphone’s diaphragm, causing a sudden spike in the audio level, and potential clipping.

To fix popping, you could spend a few bucks on a pop filter. It’s a thin circle of material that absorbs that fast moving air causing the popping.

If budget is your concern, you always make your own pop filter.

Take some unused (preferably new) pantyhose and stretch them over a coat hanger.

Bend the coat hanger into a rough circle shape. Attach it to your mic stand before your condenser microphone, and now you have DIY pop filter.

This will work just as well as a professional pop filter. The only difference is it looks awful.

However, there is one vocal noise that we can’t get rid of at the source, and that is sibilance.

A sibilant is that annoying “ssss” sound that comes across when a vocalist or speaker says a word that has an “s” sound in it. Can really cut through a recording unpleasantly.

The only way to fix that is to use plugin called a de-esser. This is really a compressor that controls the specific frequency that the sibilant sounds.

You can read more about sibilance from Wikipedia if you feel to nerd out on some knowledge.

Environmental Issues

Sometimes the problem isn’t you or your equipment, it’s the outside world. Planes flying overhead, passing traffic, air conditioning – they can all ‘bleed’ unwanted sound into your microphone. Shut all the windows in your house or studio, pull the curtains and record in a room near the center of your house, far from the disturbances outside.

Consider recording at quieter times of day if there’s rush hour traffic near your home studio or record late at night when there are almost no passing cars.

Let’s say you’ve done all you can, and still you have bad recordings to contend with. Or perhaps your audio source is from an old tape or vinyl, what do you do?

Well let’s talk about some softwares that you can use.


Best Audio Restoration/Enhancement Software Tools

There are various plugins to clean up recordings. In another guide we talk about the various plugins that exist to restore audio.

But in this article we’ve focus on two great options: the ERA Bundle, and the iZotope RX.

Even though they are very similar plugins, they have fairly different focuses.

ERA Bundle vs iZotope RX, which is best?

ERA Bundle by AccusonusERA Bundle by Accusonus

The ERA Bundle is a fairly new plugin with some powerful features focused on music production exclusively.

The bundle comes with four plugins: a De-esser, Plosive Remover, Noise Remover, and Reverb Remover.

Early we mentioned that a de-esser will remove those “sibilants” from a vocal recording. If plosives got through your pop filter, or your recorded without one, ERA offers its one knob solution: turn and dial it down.

Pretty exciting is the fact that not only do they have a noise remover, which can clean up background noises, but you can turn a pretty wet recording into a dry one thanks to Reverb Remover.

This plugin bundle is highly recommended, since it offers one of the simplest solutions out there. And for a very good price as well. Plus, it’s compatible with all the major DAWs out there.

Check price @ Plugin Boutique

See this video on how to remove reverb using ERA Reverb Remover.

iZotope RXiZotope RX

If you want something for restoring vinyl recordings, fixing clipping in your audio recordings, or you work on film, dialogue, TV, iZotope RX is a your best option.

iZotope RX is pretty much a full-featured audio enhancement and restoration software, operating both in plugin and standalone mode. So it offers a slightly different tool-set (and at professional price-tag).

iZotope RX offers the ability to fix audio levels, restore vinyl recordings and phone audio recordings, get rid of mic bleeds, as well as remove plosives, sibilants, and other noises. There’s not a lot it can’t do.

It works within most major DAWs too, so you can use it in your favorite editor without a steep learning curve. For film and TV post-production, RX Elements will give you stunning flexibility. No matter what you use it for, you’ll be getting world-class audio in no time.

Check price @ Plugin Boutique

Take a look at how to remove unwanted sounds with iZotope RX

When considering your software options, the ERA Bundle Standard or Pro is best for music producers who would may find the iZotope RX Elements/Advanced a bit of an overkill in features (and price).

But if you’re looking for an all in one solution for whatever you come across, then iZotope RX is your best choice.

What about Audacity?

Audacity offers noise reduction solutions, and is a favourite among some audio producers. But being free, it’s fairly limited in its built in features. And since it’s a stand-alone software application, it’s not compatible with your DAW.

However, Audacity utilizes plugins just like your DAW, so both the plugins mentioned above can work right inside Audacity for audio restoration.

Download Audacity

Watch this video to learn how to use ERA plugin bundle inside of Audacity.


Final Thoughts

Audio enhancement starts at the source: how you record your audio.

With the right recording equipment, and the proper methods, you generally cannot fail. But for those times when we do, or when we need to restore or enhance a recording from vinyl or another source, it’s good that there are a couple software solutions out there that we can turn to.

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