Fundamentals (Part 4): Understanding Hertz

Updated: Aug 4

Introduction

In the world of audiovisual technology, understanding various technical terms and concepts is crucial for both professionals and enthusiasts. One such fundamental concept is Hertz (Hz), a unit of frequency that plays a pivotal role in various aspects of AV technology. In this fourth part of our fundamentals series, we will delve into the concept of Hertz, its significance, and how it affects your AV experience.

What is Hertz?

Hertz (Hz) is the unit of measurement for frequency, named after the German physicist Heinrich Hertz. Frequency refers to the number of cycles or oscillations that occur in a specific period, typically one second.

In simpler terms, Hertz measures how often a repetitive event happens per second. For instance, if a sound wave oscillates 1000 times in one second, it is said to have a frequency of 1000 Hz or 1 kHz (kilohertz). In the AV industry, Hertz is commonly used to describe the refresh rate of displays and the frequency of audio signals.

Importance of Hertz in Video Displays

Refresh Rate

In video displays, the refresh rate, measured in Hertz, indicates how many times per second the image on the screen is refreshed. Common refresh rates include 60 Hz, 120 Hz, and 240 Hz. A higher refresh rate results in smoother motion and reduced motion blur, which is particularly important in fast-paced content such as gaming and sports.

Frame Rate vs. Refresh Rate

It is essential to distinguish between frame rate and refresh rate. Frame rate refers to the number of frames displayed per second (fps), while refresh rate refers to how often the display updates the image. A display with a high refresh rate can show the benefits of high frame rate content, leading to a more immersive viewing experience.

Importance of Hertz in Audio

Audio Frequency Range

In audio, Hertz measures the frequency of sound waves. The human ear can typically hear sounds in the range of 20 Hz to 20 kHz. Low frequencies (20 Hz to 250 Hz) correspond to bass sounds, mid frequencies (250 Hz to 4 kHz) cover the midrange, and high frequencies (4 kHz to 20 kHz) include treble sounds. Understanding these ranges is crucial for audio engineers when equalizing sound and ensuring a balanced audio mix.

Sample Rate

Hertz is also used to measure the sample rate in digital audio. The sample rate refers to how many times per second an audio signal is sampled during the analog-to-digital conversion process. Common sample rates include 44.1 kHz, 48 kHz, and 96 kHz. Higher sample rates can capture more detail in the audio signal, resulting in higher audio fidelity.

Practical Applications of Hertz

Choosing the Right Refresh Rate

When selecting a display, consider the refresh rate based on your primary use. For everyday tasks and video streaming, 60 Hz is typically sufficient. However, for gaming or professional video editing, higher refresh rates like 120 Hz or 240 Hz are recommended to enhance the visual experience and reduce lag.

Understanding Audio Equipment Specifications

When evaluating audio equipment, pay attention to frequency response and sample rate specifications. These metrics will give you insight into the equipment's performance and suitability for your needs. For instance, studio monitors with a wide frequency response and a high sample rate will provide more accurate and detailed sound reproduction.

Conclusion

Hertz is a fundamental concept in AV technology that impacts both video and audio quality. By understanding Hertz and its applications, you can make informed decisions when selecting AV equipment and optimizing your setup. Whether you're a professional in the industry or a passionate enthusiast, a solid grasp of Hertz will enhance your AV experience and technical expertise.