How to Improve the Audio Quality of Voice Recordings

Audio content can be divided into four categories:

Category 1: Bad Content + Bad Audio Quality;
Category 2: Bad Content + Good Audio Quality;
Category 3: Good Content + Bad Audio Quality;
Category 4: Good Content + Good Audio Quality;

You’ve worked hard to create good content for your podcast, audiobook or YouTube video. But good content deserves good audio quality.

So in this article I’ll present you with some rules to follow. Follow them and get your yourself into the Category 4.

Rule 1. Use Proper Recording Equipment

Look, gear is not everything — if you buy a nice microphone but don’t follow the checklist, your sound will continue to suck — but it’s still important. To sound better, try this:

1.1 Buy a better sounding microphone

There are microphones that just. sound. good. They usually cost more money but if your budget allows you to buy a good professional microphone, go for it!

Here are a list of some of the most popular gear being used today for recording voice.

Shure SM58

The SM58 is not expensive but it will still help you get a professional results. The boosted notch @ 5000 hz will get you a more radio, broadcast vibe.

Shure SM7B

The most popular podcasting microphone.
Note: before buying this microphone, make sure you read Rule 3

Rode NT2A

Unlike the previous microphones, this one is a Large Diaphragm Condenser microphone. Instead of giving that radio-like, broadcasting feel, this one give warmer tone to the voice. It has a good compromise between price and quality. This is the microphone I personally use. However, make sure your recording room is properly treated acoustically.

Sennheiser MKH-416

Legendary microphone, standard use in Hollywood to record film dialogue, and also a common choice among voice-over professionals.

Focusrite Scarlett 2i2

An affordable preamplifier with good quality. You need this to connect your microphone to your computer via an USB connection.

Even if your budget is limited, you can still improve your microphone. We researched some budget USB microphones and wrote one article about it.

1.2 Buy a microphone with better background rejection

Microphones have polar patterns, which determines how they record and reject sounds.

  • An omnidirectional microphone records sounds from all sides and rejects no sounds. This can be, as you can guess, inconvenient. If you’re using one of these (such as a lavalier microphone), you need to make sure you compensate for this, by recording with the microphone close to you, in a quiet environment.
  • A cardioid microphone rejects sounds from the back – which is excellent – but is still sensitive to everything in its front and sides. You need to keep this in mind, and adjust its position in the room to reject unwanted sounds.
  • A super-cardioid microphone rejects more lateral sounds than the cardioid but records a bit from the back. You can get a better background noise rejection with a supercardioid microphone than with a cardioid, if  you know how to position it appropriately. This means that you don’t put it in a room with noise coming that the 180º angle. One such thing that usually comes from that angle is the room late reflections. So, they will work best in an acoustically treated rooms.
  • Shotgun microphones: these are highly directional mics, rejecting lateral sounds. However, they also are very sensitive to sound at the 180º axis (that is, behind it). So, just like the supercardioids, they should be used in acoustically controlled environments, preferably.

1.3 Use a Pop-Filter

Don’t record yourself without a pop-filter. Pops make you sound unprofessional. This is what a ‘pop‘ sounds like:

Avoid this by putting a pop-filter in front of your microphone.

Microphone Pop-Filter

Rule 2. Record Near the Microphone

When you’re recording yourself, there’s a powerful Physics law at play: the inverse distance law.

In practical terms, this law means that as you get closer to the microphone, the separation between you and the background noise increases exponentially! This is an extremely powerful piece of information.

The graphic below helps to visualize better what happens to the voice and background noise levels as you get closer to the microphone.

Simply stated: the closer you record to the microphone, the less background noise you get.

And as you do that, you also get something called the proximity effect: a boosting of the low frequencies of your voice. This may be desirable if you want to add ‘weight’ to your voice. Just make sure it doesn’t become overbearing! If that happens, back away a little bit.

Rule 3. Set your Levels Rights

Record yourself with the proper levels. You do this by adjusting the gain control on your audio interface, and make sure the levels are, on average, hitting somewhere between -24 and -12 dB. The image below shows you how it looks like:

Why -24 and -12 ? Because:

  1. If your levels are hitting numbers above-12dB on a regular basis, it means that you are leaving no room for any unpredictable louder words/laughs/etc. If these happen, they will most certainly hit the 0dB ceiling and be recorded with distortion.
  2. If your levels are recorded way below -24 dB, you will need to bring your recording levels up afterwards (a process known as normalization) to be able to hear your voice. But doing this will also expose all the low-level noise that would have never been heard, had not normalization been applied. Take a listen to this extreme example:

Please note: if you’re considering getting the Shure SM7B that was mentioned before, you need to be aware that this microphone requires a lot! of gain. This means that you need to push the gain on your audio interface to the max to get a good level. And sometimes even this may not be enough. If you find yourself in this case, you may need to get yourself a piece of gear called Cloudlifter.

Cloudlifter CL-1

Microphones that require lots of gain, such as the Shure SM7B, usually respond better when combined with a Cloudlifter CL-1. The Cloudlifter adds a clean boost of 25 dB to the microphone signal.

Rule 4. Record in a Quiet Space

We’ve talked about two ways to reduce background noise:

  1. Choosing an appropriate microphone polar pattern.
  2. Recording closer to the microphone.

But do you know what beats that? Having no background noise at all!

So let’s divide background noise into three categories and see what can be done to reduce it:

4.1 External Noises Beyond Your Control

Normally, you can’t silence these sounds. They include traffic, birds, dogs, children playing outside, other city noises and so on. You have three choices to deal with this:

Time: choose another time to record, when things get quieter. This typically will be at night.

Space: record in another location where there are no external noises beyond your control.

Soundproof your room: this is not realistic for many people but it’s still a solution and should be mentioned. It involves re-building your room to accommodate for soundproofing solutions (sound isolating walls, doors, windows, etc).  

4.2 External Noises Within Your Control

If you can silence a background noise, you must silence it. These include fans,roommates, TVs, etc.

A common problem for people who record themselves is their computer fans. There are three things you can do about this:

1. Turn off the computer fans while you’re recording;

2.Buy a silent computer tower + silent PSU;

Silent Desktop Tower

Silent PSU

3. Buy a portable audio recorder and record yourself with the computer turned off.

Zoom H6 – Portable Audio Recorder

4. Also, use the microphone polar pattern in your favor: point the rejecting areas of the microphone to the computer fans.

4.3 And finally, the last source of background noise: You…

Most people are conscious enough not to make unwanted noise while recording, but some are not. We’re talking about paper rustling, keyboard and mouse clicks and squeaking chairs, stomach growls and so on.

These sounds are fine if they happen when you’re not talking – they can be removed easily.

But they must not occur while you’re talking. If it happens, re-do the sentence. 

Rule 5. Record in an Acoustically Dead Room

This means recording in a room without noticeable reverberation (what most people call echo).

Some rooms are more reverberant than others.
A room itself can have some spots that are more reverberant than other spots.

Being aware of those spots is important.

But to truly achieve good professional results, you need to add sound absorption to your room:

  • Avoid empty rooms with bare walls. Curtainssofas, mattresses and thick carpets all help to absorb some sound.
  • Buy some absorption panels and position them in strategic positions (your sides, behind you, above you). Doing this will dramatically deaden your sound (in a good way).

Acoustic Panels Pack

This is an affordable pack for giving your room a basic acoustic treatment. Sure, a complete could easily cost you 1500€ but if you don’t want to go there yet (hell, even I haven’t gone there yet), this is a good place to start.

A quick and dirty solution…

Do you need a quick and dirty solution to get by until you buy real absorption panels? Cover yourself and the microphone with a heavy blanket. A few years ago we had to improvise an ‘acoustic bunker’ for a vocalist. It didn’t work too bad…

Better still, if this is something you can do: close yourself in the closet with a portable audio recorder, and record there for maximum audio absorption. I remember YouTube Mouthy Buddha said this is was how he recorded his videos.

These are the 5 rules. Follow them to sound better.