Gain vs. Volume – What is the Difference?

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Written By Tanya

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You’ll eventually ask the question, “What’s difference between gain or volume?”

They look almost identical to the untrained eye. Both make the audio sound louder if you increase their gain. You might think they sound the same if you are dancing at an acceptable level of gain.

There are many components in your signal path that can cause problems, analog and digital. If you don’t know how gain affects volume, it could be a problem. It’s easy to understand.

You will get higher resolution recordings, clearer mixes, better headroom and a wider dynamic range with respect to amplitude. Let’s get started so that you can immediately apply these lessons in your mixes and recordings.

Gain vs. Volume – Understanding Each Separately

Before we can compare these properties of audio, it is important to understand each one. Both modulate the amplitude and translate into changes in volume.

It’s no wonder that people are confused. The image shows two knobs that appear to do exactly the same thing. Not quite!

What is VOLUME?

Volume is what you are probably used to thinking about and dealing with. The speakers will get louder when you turn the knob on the car radio. Push up the fader of a mixing console, and that track becomes louder. This is a practical, real mystery.

Volume refers to the volume of an audio system measured in decibels. A sound system can be described as a collection of speakers, headphones, headphones, an aircraft, a chainsaw or someone whispering in your ears.

In this instance, a “system” can refer to anything that produces sound. The decibel scale can be used to measure volume. The louder the sound, the higher the decibels. Sound pressure levels (SPL), and sound intensity are both important, but we won’t go into detail.

It is possible to adjust the volume of a speaker system without affecting the quality or tone. The audio signal will not change if the speakers start to distort. Volume is at the output and cannot affect audio quality.

Let’s now compare that with gain. The difference should be obvious based on the volume I have emphasized. Don’t be alarmed if it doesn’t. I will do a direct comparison right after.

What is Gain?

Gain refers to the ratio of the volume at an input and output of an electrical circuit. It is what it is, despite all other websites telling you that it’s only “the volume at input”.

The complicated world of electronics, which includes voltage and current (everything that we record), makes it even more difficult. Voltage is the direct corollary of volume.

These websites want you to find it easier to understand because volume is not what they are trying to sell. Although it is a simpler way of thinking about it, it doesn’t necessarily reflect the whole truth.

Problem is that not everyone understands gain, but some think they do. It’s true that some professionals understand it, but they don’t care if others misuse the term.

One example: Gain-reducing plugins and hardware units will often call the output volume “makeup gain,” which is not correct but is a common convention.

Practically, gain can be described as volume at the input. Once you get a better understanding of it, I’ll continue to explain. What is the real question? In a moment, I will tell you.

The Difference between Volume and Gain

Gain, in plain English, is a control knob that controls the loudness after it has passed through the circuitry. Volume controls the loudness once it has passed through electronics.

All of us know what a volume knob does and how to use them. Volume doesn’t alter the sound quality. It simply raises the volume of the whole system.

The quality and tone of a song can be affected by how you adjust the gain knob. Gain is simply the ratio of the output amplitude to the input amplitude. Consider a “system” or audio system and consider it an electronic signal path.

Analog audio has a peak ampltude, which is determined by voltage. This allows you to get louder before it gets too loud. Digital audio has a maximum amplitude that is determined by the system’s bit depth. This can be very complicated, so I suggest you read our article headroom to get more information.

It is important to remember that there is a maximum volume within an audio system before distortion occurs (as controlled via gain), but there is no maximum volume outside the system’s output (as managed by volume).

This is the main difference between volume and gain. The question now is: What does gain mean and how does this affect audio quality?

What does Gain do?

Let’s look at three simple examples you have likely encountered. The first example is one of a microphone preamplifier. The second is an analog-to digital converter. And the third is a guitar amplifier.

These are all simple signal paths, but they have different output scenarios. This makes it easy to understand.

SCENARIO #1 – MICROPHONE PREAMPS

Every novice plugs in their microphone, records a take, and then wonders why the volume is so low. They turn the volume up to an acceptable level, but there is a lot of noise. This is why?

Microphones record at “mic level”, which is a quiet signal due to the lack of amplitude. This is due to the way microphones are constructed and how sensitive they must be to pick up small details in the audio they capture.

You will need to increase the volume of the microphone’s input signal. A microphone preamp is used to do this. It is essential that you use one. If you need more information, please visit our What is a Preamplifier article.

This is because audio signals have a noise floor. It is a low level of electronic noise. You need to make sure that the audio signal is louder than the noise floor. Otherwise, you will get a noise recording if you increase the volume at the output.

This is what a preamp does for you. The best mic-preamps offer 60 dB gain. This is the main function of the gain knob on a preamp, but there are more details in the next scenario.

This example shows how gain can improve quality by increasing the amplitude (amplifying) above the inherent noise in an audio system. We’ll look at another way that it improves audio while you actually record.

SCENARIO #2 – ANALOG-TO-DIGITAL CONVERTER

Let’s move on to the audio that we recorded using a microphone and sent through the preamp. The audio will then pass through an analog to digital converter (ADC) which is located in your computer’s soundcard, or an audio interface. There are both good and bad ADC’s, but all have limits on the amplitude.

This ADC converts electrical signals from the physical world into digital ones that your computer can understand. It interprets voltage and current to determine the volume and frequency of the audio. The situation is that has an optimal loudness level that can use to record the best quality audio.

The bottom line is that you want loudest audio possible to pass through the converter in order for it to fill all bits of data with as much information as possible. The computer will play back audio at a higher quality if it has more information.

You can get distortion if you play too loud. This is due to the maximum voltage within the system.

This is why we have input gain knobs. We can achieve the best audio quality possible by riding as close to the maximum voltage as possible. To prevent you accidentally clipping, limiters are available. You will learn more!

SCENARIO #3 – GUITAR AMPLIFIERS

Imagine a guitarist in heavy metal who wants to create distortion. Two problems arise. They only have a volume knob that can’t produce enough voltage to cause distortion at an amplifier. Like a guitar, a mic needs help producing enough loudness. Think of the amplifier as the “enclosed sound system” here.

A second problem is that too much voltage can damage the tube of their amplifier or the speaker. This is how many guitar players used to create distortion. There’s a better method.

We don’t have to increase the volume of the guitar and then pulse the amp’s encapsulated system, but we can simply hit the maximum voltage of the guitar pedal that was designed for this purpose. We use a boost pedal or our best distortion pedal to increase the volume and allow those who are listening to it to hear more of their electronics.

The distortion pedal will output a distorted sound to the amplifier. This signal is played back as a distorted one even though it is not causing distortion at the amplifier. The enclosed guitar pedal system’s audio gain allows us to feed the amplifier a signal at an acceptable volume and still achieve the same effect.

Understanding gain requires that you think of every component in the signal path as an independent, autonomous “audio system”, with its own inputs and output levels.

Gain staging is a whole science. We’ve already written about it for you to see. This is an important topic that everyone involved in music should be aware of if they desire top quality (or acceptable) audio.

Gain vs. Volume – Simple to Understand

You can go deeper into the fascinating world of acoustics by exploring how loudness is subjective and how our perceptions of volume vary at different frequencies. It has been described as the Fletcher–Munson curve.

Gain and volume are two different things. It is important to understand the differences. Volume is the control of how loud a sound system outputs, and it has no effect on the quality. Gain, however, allows you to increase the volume inside an audio system. This determines the quality or recording.

Although you may not be a musician, if you are involved in music, please read our article on gain staging. If you are serious about quality, then you must know how to use gain. It is simple to understand volume vs gain. However, it is more difficult to use gain correctly.

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