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.
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
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.
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.
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.
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.
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.
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!