In today’s post, we’ll explore the differences between Preamp and Master volumes and how they relate to each other.
So what’s the real difference between preamp volume and master volume?
The difference is that preamp means input, and master means output. When you turn up the preamp volume, you affect the signal before all other effects you may add to your channel. When you raise the master volume, you control the sound after being through the whole signal chain.
Increasing the preamp volume can result in interesting results. It’s been used throughout the history of music production to add character to the source signal. Nowadays, even the smallest mixing desks with built-in preamps have a gain knob, which feeds the preamp. Since we’re tackling the signal as it’s coming into the mixer, hence “input,” it’s the first stage of sound processing. Then, one might add EQ, compression, delays, or many effects to the sound.
After every effect has been added, the result is a processed track whose overall volume can be adjusted to taste. This stage of sound processing is the last and is where you finally apply the master volume. Increasing or decreasing the master volume does nothing to the sound’s character; it only adjusts the loudness.
These concepts have suffered slight changes from the days of tube hardware and magnetic tapes, but their functionality’s still the same in the digital age.
Read on to understand both terms:
What is Master Volume?
With master volume, you control how loud a signal is played back. Adjusting the master will only change how loud you perceive it overall. In your DAW, you can do it in two different stages – In an instrument channel and the output channel.
- In an instrument channel, like a kick drum, you adjust how loud it sounds by itself. This will change how it relates in volume to the rest of your production.
- In the output channel, you control the Master Volume, increasing or decreasing your entire song’s output loudness. This changes how loud you hear the production as a whole.
You see here that the process is the same in both cases: you’re raising or lowering a fader that causes the output volume to go up or down. Even if it’s a single track’s volume or your entire song’s, the master volume doesn’t change timbre nor adds distortion.
What is Preamp Volume?
Preamp volume is the process that makes the sounds being captured by a microphone become audible. It is measured in dB, and generally, a preamp adds up to 60dB of volume to the signal. The correct amount of volume to be added depends on the microphone, the instrument, and the preamp itself.
Here’s an example for better understanding:
When recording a singer, the microphone captures the person’s voice as mechanical waves. It automatically converts this information into an electrical signal that your audio interface recognizes as sound.
This sound is at a meager volume, so it needs to be amplified to be heard. This is done by a preamp, which most audio interfaces have. This preamp increases the microphone volume to a standard known as Line Level, which is the minimum necessary for your interface to recognize it.
You can then adjust the preamp volume on your interface. This will affect how the sound is sent to your DAW. Too little volume here can cause a very shallow and uninteresting sound. Too much volume and your preamp will distort the signal, which means a harsh electronic noise in today’s digital world.
There is no right or wrong in adjusting preamp volume, only the setting that will get you closer to your desired sound. When adjusting the input volume, you must analyze the instrument’s characteristics and the microphone you’re using. Dynamic microphones need more preamp volume than condenser microphones. Consider how much dynamic headroom you need to apply effects to the process later on.
After you’ve recorded the singer’s voice, your resulting information is an audio clip on your DAW that retained the input volume you’ve set for it. After adding the desired effects to your recording, all you can do with it is adjust the master volume.
How The Preamp Volume Influences The Master Volume?
The more you turn up the preamp input, the more distortion or coloration you’ll add to the sound. Turn it up too much, and you’ll have to start lowering your master fader to hold the overall volume down.
In analog audio, preamp volume is known as input gain. The process is virtually the same, but since we’re dealing with analog hardware, the results are quite different. In this context, preamps are tools used to help microphones achieve line level and add character to the sound.
Here’s a quick explanation about outboard preamps:
Some engineers even have preamp and microphone combinations they like to use to produce certain sounds and textures. It is not uncommon for mixing boards and guitar amplifiers to have their own built-in preamps, making them unique. In a guitar amplifier such as the VOX AC15, you have a knob to control the input signal and another for the master signal.
In this Vox AC15 amplifier, we can see the signal flow and both volume controls on the edges. The one on the right is the preamp volume, while the one on the left is the master volume.
Turn up the first one to get a crunchy, distorted guitar sound. If it gets too loud, turn down the master knob a little to find the sweet spot. By doing so, you’ll still preserve the harmonic qualities added by the preamp without it sounding exaggeratedly loud.
Do not apply the same logic to preamp plugins in the realm of digital audio. Since they’re not technically preamps, they are handy tools that can add saturation or some EQ curve to a sound. They don’t amplify the signal from the microphone into line level. Ergo, they’re not real preamps.
What is volume?
In audio, the volume is defined as how quiet or loud a sound is being played back. It is a psychoacoustic sensation perceived by the listener and measured in decibels (or dB). Volume is the common name given to the loudness levels produced by any sound source.
In our everyday lives, sounds come in all kinds of volumes. Our ears and brain measure them according to their source’s distance from us. A dog barking at your neighbor’s backyard will sound much lower in volume compared to the same dog barking in front of you.
This same logic was used in the very early days of music production when all that the studios had access to was a single microphone. The mix was done by placing musicians and their instruments closer or further from the microphone, according to how important they were to the song. Instruments in front of the microphone sounded a lot louder than instruments in the back of the room, but it was never an exact science, and the result wasn’t so great compared to modern standards.
As technology improved, the volume became a lot easier to handle. Mixing boards started having more and more channels, and we went from a single microphone in the room to sixteen only on the drums!
Preamp and Master
Volume can be measured before or after the sound has been recorded. Before recording, when you’re capturing sound originated either from a mechanical wave or digital signal, you’re dealing with the preamp volume. After you’ve recorded the signal, you’re dealing with the master volume.
While some engineers and artists work all their lives to achieve the cleanest, most pristine sound, with dynamic volumes and beautiful, natural colorations, others, in the maverick side of things, go all the way up on those preamp knobs to get a different, down and dirty sound.
The tools are here to be used and improved over time. With the decline of the loudness war, textures are becoming just as important as dynamics. You won’t convince your audience with sheer volume anymore. Think about it next time you’re recording and try to find whatever sound suits your production best!
Pedro Nascente is an artist, record producer, and mix engineer, currently operating his own studio and working with his band, Yellow Boulevard. Believing that music should convey experiences and feelings, Pedro is known for applying design thinking to his workflow to achieve different sounds and deliver the right messages.