Understanding Decibels – A Beginner’s Guide

Understanding Decibels - A Beginner’s Guide

Decibel is a word that is casually thrown around in the music industry.

In fact, many people are already familiar with the term long before they have anything to do with mixing, mastering, or even recording for that matter. 

It’s our fair guess that you too have a rough idea of what decibel means.

You know it has something to with sound as you vaguely remember that science lesson from middle-school.

But if you are here, you are probably looking for a more clear explanation to ‘what are decibels?’

If that’s the case, you have come to the right place!

In this guide to understanding decibels, we will shed light on the basics of decibel and its importance in making your own music.

So, What Exactly Are Decibels?

Contrary to popular belief, the decibel is not a unit of sound.

Although it does represent the level of loudness of an audio wave, it is not a unit of measurement of sound intensity per se.

The decibel, denoted by the letters dB, is actually a ratio.

The decibel literally means one-tenth of a Bel.

The Bel is a unit of level named after Alexander Graham Bell, an American scientist credited for inventing the first practical telephone.

Decibels compare the value of one quantity to that of another.

They are numbers that let us denote extremely large ratios in a way that is easily comprehendible on a logarithmic scale.

Why Are They Important for Making Your Own Music?

Why Are They Important For Making Your Own Music?

From the point of view of a composer, what you need to know about decibels is that they are a way of representing the Sound Pressure Level (SPL).

For example, if you come across a speakers that can blast music at 100 dB, what it really means is that it can generate sounds at 100 dB SPL.

As we mentioned earlier, the decibel is a ratio. So, the 100 dB is basically a comparison to something.

But what?

The 0 SPL.

0 SPL, in turn, symbolizes the standard atmospheric pressure of the air. This is equal to 20 micro pascals.

The zero sound pressure level is said to be the lowest level of human hearing, which means that under normal circumstances, you would not be able to perceive sounds below this value.

The main reason why decibels are so crucial for making your own music is that they help you keep track of how well your mixes will be received by an average listener.

In the audio world, decibels are used to compare changes or two different levels of signal voltage or power.

They help you measure the voltage and power in your sound recording and playing gear and play a primary role in analyzing the response of an audio signal using an equalizer.  

The Decibel Scale and Music

Decibel Scales

Another essential thing to keep in mind when it comes to decibels is that unlike most other units of measurement that are linear in nature, decibels are not.

These ratios are based on a logarithmic scale.

Why?

Because of the sensitivity of human hear. You might not have paid attention to it so far, but your hearing system is an incredible thing.

It can help you hear the faint rustle of leaves outside the window, the sound of the jet passing through the clouds to everything else in between.

If you consider these sounds in terms of power, the sound of the jet is more than a billion times louder than the rustle of leaves.

You cannot represent such huge numbers on a linear scale. This is why the decibel scale is logarithmic in nature.

The way in which the decibel scale is read and what the changes in dB levels denote correspondingly can seem rather odd and confusing at first.

To interpret the numbers efficiently and effectively, you can use this cheat sheet.

  • The smallest audible sound (almost complete silence) – 0 dB
  • A sound signal that is ten times stronger – 10 dB
  • A sound signal that is a hundred times stronger – 20 dB
  • A sound signal that is a thousand times stronger – 30 dB

And so on.

Put simply, if the SPL value increases or decreases by ten units, it means that the corresponding audio signal becomes stronger or weaker exponentially in powers of ten.

What Is the Optimal dB Value?

What Is The Optimal DB Value?

The optimal decibel value for humans is about 85 dB. Sound waves that are higher than this level can cause hearing damage and, in extreme cases, lead to permanent loss as well.

When listening to loud music, the power of the audio signals and the length of exposure both play a major role.

Listening to a 90 dB mix for more than six hours can create pain and discomfort that will persist for days.

When recording vocals, try to record at around -18 dB. The loudest part of your recording should not go beyond -10 dB, whereas the lowest parts should stay within -24 dB.

How to Increase Recorded Decibels?

Listening to the tracks that you just recorded only to realize that the sound seems to be coming from a far off distant place can be very frustrating.

Low volume audio files are usually close to useless, especially if you cannot rerecord the original audio.

But before hitting the delete button and starting all over again, consider increasing the decibels. There are various software packages that let you do this effortlessly.

Two of the best tools for increasing recorded decibels are:

MP3 Louder

MP3 Louder is a free web service that presents you with an extremely easy way to increase the volume of your recorded soundtracks.

All you need to do is visit the MP3 Louder website and select the appropriate options before uploading the audio file.

You need to choose the number of decibels by which you want to boost the sound quality and select the desired channel (left, right, or both) as well.

Upload the file in mp3 format and wait for a few minutes.

Remember not to close or refresh the webpage during this time; otherwise, you will have to repeat the process as the encoding won’t be completed properly.

You can also use this online tool to decrease the volume of an audio file.

Audacity

Audacity is a free web tool for sound editing that is just as good as various paid-for alternatives (if not better).

This online audio editor allows you to enhance the quality of your recordings, whether you are composing music or making podcasts or audiobooks.

One of the best features of Audacity is that it lets you increase the volume not just for the whole length of the recording, but also for a part of the track.

This is really helpful if you want to amplify the sound where you play a certain musical instrument.

This desktop tool is compatible with all operating systems, including Windows, Mac OS, and Linux.

How to Decrease Recorded Decibels?

How To Decrease Recorded Decibels?

If you are asking this question with respect to decreasing the ‘loudness’ of your soundtrack, the obvious answer will be to turn down the volume.

But if you want to learn how to decrease recorded decibels such that it improves the overall quality of your mixes, you need to focus on reducing the background noise instead.

To record high-quality audio, you need to keep the recording gear free from dust and dirt.

You must position the mic properly near the sound source and soundproof your home studio too.

However, if you fail to take the required measures or find that somehow the recording is not perfect despite following the proper steps, you can clean it up using software tools and similar applications designed for the purpose.

The two tools mentioned earlier for increasing decibels can also be used to decrease recorded decibels.

Alternately, you can use services like ERA Noise Remover and iZotope RX 7 to refine your audios and give them a professional touch.  

Pro Tip: Be it online tools or desktop applications, when using any software to change the value of recorded decibels, make it a habit not to work directly on the original file.

Instead, use a copy of the main file to make the edits.

This saves you from major setbacks on your music composing journey because if you aren’t pleased with the results even after editing, you can easily go back to the original version and modify it in a different way.

End Note

Most people recording in their home studios do not truly appreciate the concept of decibels or realize its effect on sound quality.

But if you are a music enthusiast who wants to make the most of their mixes, it’s crucial to understand this fundamental concept in acoustics.

After all, trees grow to great heights only by further deepening their roots into the ground.

Whether you want to gain something of significance through your recordings or just want to liven up to the exhilarating experience that music composing really is, knowing what is decibels will prove beneficial along the way.

Refer back to this guide if you ever need help in interpreting what the numbers labeled ‘dB’ on a piece of equipment mean.

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