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What is a Peak Meter in Audio? – Accuracy in Measurement!

Have you come across any instruments that are used to measure audio signal levels? Well, perhaps you have, but did not realise it. These devices are more common than you think, and there are several types of them that are used in professional audio applications. A good place to start learning, is to find out what is a peak meter in audio.

The subject that we are discussing for today is a pretty straightforward and simple one. Hence, I will try to keep it short and concise, while still covering most of the major points. In particular, you will be able to learn about the specific function of this audio level meter, and how it helps to facilitate a professional audio production!

Peak Meter – The Importance of Accuracy

A sound level meter that visually indicates the instantaneous level of an audio signal that is passing through it, is called a peak meter. In the world of professional audio production, the sound level meter, regardless of whether it is a “peak” type or not, is typically designed to correspond to the perceived loudness of a particular signal.

Sound Level Meter

A peak meter happens to also be an instrument that measures the peak value of a waveform. For example, when recording audio, it is ideal to be recording at a level that is just strong enough to reach the maximum capability of the recording device at the loudest sounds, regardless of the average audio signal level. Hence, a peak meter is often used to set the recording level.

Here are the topics that we’ll be looking into:

  • Modern equipment
  • Older equipment
  • Human hearing

Modern Equipment

Most of the modern recording equipment used today, have peak meters that are made up of a series of small LED bulbs, usually placed in a vertical or horizontal bar. These bulbs will light up in response to the audio signal’s fluctuations. There are many methods used in designing these meters. They typically have ranges of green, yellow, and red bulbs, to indicate when a signal is starting to overload.

LED Type Meter

An LED meter used on a mixing console

Do take note that the term “peak”, is a representation of the meter’s ability to indicate the highest output level at any instant, regardless of the type of visual display.

Older Equipment

Peak meters that are often found on older analog recording equipment, uses a classic moving needle device instead of LED bulbs. They actually look similar in some ways, to a pressure gauge on a bicycle pump or other similar devices. Most older equipment incorporated actual moving parts into their sound level meters in order to indicate the audio level.

PPM Meter

A peak meter designed to incorporate a needle / Photo by Harumphy / CC BY-SA 3.0

However, due to the mass of the moving parts and mechanics, most older meters exhibited response times ranging anywhere from a few milliseconds to a second or more. This makes the older meters less reliable, as they might not ever produce an accurate representation of the signal at any point in time. But the constantly changing level, combined with the slower response time, led to more of an “average” indication.

Human Hearing

Peak meters are designed to respond very quickly to changes in the audio signal that is passing through it. In other words, the meter display actually reacts in exact proportion to the voltage of the audio signal. This degree of accuracy can be useful in many audio applications, but the human ear works much more like an average meter than a peak meter.

VU Meter

A VU meter / Photo by Iainf / CC BY-SA 3.0

The human ear’s perception of sound level is actually closer to the response of analog VU meters, which are designed to have a slower response time (around 300 miliseconds). Hence, there are still some audio engineers and practitioners who prefer to use older analog VU meters, as they relate more accurately to what a human listener will experience in terms of relative loudness.

We have come to the end of this article. I hope you now have a good understanding of how peak meters work, and what they are used for.

Do leave your thoughts down below, and share this article with your friends!

Farhan

When I'm not rocking out to great music, I'd prefer to be sleeping on a field on a windy day =)

4 Comments

  1. I love this post. I find that many new producers don’t know what it is or pay very little attention to it and the information it provides. The concept of Headroom and dynamic range is lost and many simply want that “wall of sound” because they think it would make a good mix. Thank you for sharing.

    • Hey Ryan!

      Yeah, many young producers do not fully understand and appreciate the importance of these sound level meters. Glad you got something out of this post!

      Thanks!

  2. Another valuable educational and informative post about audio. Actually for many music listeners and me not so important to know much about a peak meter, but I remember good old days when recording from vinyl to magnetic tape was one of the main ways to make good music collection.
    Peak meter was the main indicator to get proper results.

    • Hi Andre!

      Yeah, peak meters are actually more important than what most people think. But I guess you’re right in saying that most consumers will probably not pay much attention to it. Well, I’m happy that you’ve learnt something new today.

      Thanks a lot!

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