Audio VU Meters

What is an audio VU meter?

Volume unit meter or VU meter is an essential component of a sound recording and reproduction system. It is used to measure signal levels, allowing the operator to avoid distortion, overloading, and noise.

A volume unit meter has special ballistics that identifies complex waveforms to correctly identify program materials that vary in both frequency and amplitude. For speech and other complex waveforms, this device reads between the average and peak values. It will then display the average volume of any signal that has been sent through it.

What do I need a VU meter audio for?

To be able to record an excellent mix, it’s important that you know the basic principles of audio control. This is where you will need a good volume unit meter.

A VU meter audio has a dynamic characteristic to measure the response of the human ear. For example, when a speech waveform is applied, the meter will display the peaks and valleys in the signal. In other words, this device tells you the rise and fall times of every waveform, which is difficult to get right.

A finished data file, vinyl, or CD can only have so much level before distortion and overloading. But with the help of a VU meter, you’ll be able to accurately tell where that level is.

Additionally, audiometers are also useful when comparing how much space a sound takes in a mix.

For example, you have a bassline that peaks at -3dB and a drum loop with a peak at -3dB. This doesn’t necessarily mean that this is a balanced sound. This is because drum sounds peak with short, loud transient spikes, which are higher than the whole kit’s actual loudness. On the other hand, a bassline has a low, fat transient with low peaks that are near the average level.

To correct this, set both bassline and drum loop to -3dB using an audio VU meter.

Using a volume unit meter will help avoid distortions because it can give an operator a more convincing idea of the loudness of a sound.

What else do you need?

Aside from the VU audio meter, you will also need a plugin to show the VU and RMS level more accurately.

During a live recording, a green light bar on top to show the peak. Dark green bars show RMS in the middle.

How to calibrate a VU meter correctly?

Calibration of a VU meter requires you to decide on a nominal operating level, which equals to 0VU on the device. For example, a good signal level is -20dB on the scale. To play it safe, keep the levels under -6dB.

Say, you send a sine wave gain-staged to -20dB on the peak scale. The audio meter needle remains at 0VU if you calibrate it to -20 as its normal level.

It’s important to calibrate an audiometer and adjust the levels for each fader to ensure that the needle of the audio VU meter around 0VU.