If you look over the specifications for different sets of earbuds, you will undoubtedly come across the term “frequency response”. However, you may not know exactly what this term means.
Generally, when used in a product’s specifications, “frequency response” refers to the range of frequencies, from low to high, that a speaker is capable of reproducing. But really, the term also refers to the strength of the different frequencies within that range, sometimes also called the “frequency response curve”, or just “frequency curve”. This is an important factor for all speakers, including the tiny speakers inside of headphones and earbuds.
To understand and evaluate a product’s frequency response, you must first have a basic understanding of audio frequencies and the range of human hearing.
Sound Waves & Cycles
Sound, as you probably know, is actually waves of pressure that move through the air at a very high speed. The frequency of these sound waves is measured in Hertz (Hz). One Hertz means one cycle of a wave per second.
What’s a cycle? A wave’s cycle is one complete vibration of the waveform. The wave begins, goes up to its highest part (called the peak, ridge, or crest), comes down to its lowest part (called the valley or trough), then comes back to where it started. The cycle then repeats to create the waveform pattern. Sometimes a cycle is measured from peak to peak or trough to trough instead of from origin to origin.
The higher the Hertz (meaning the more times the wave cycles per second) the higher the frequency of the sound. When the Hertz start to number over a thousand, they are referred to in kiloHertz (kHz). One kiloHertz is the same as 1,000 Hertz .
Audible Frequency Range
The range of human hearing is about 20Hz-20kHz. This means that on the low end of the spectrum, our ears can pick up deep bass frequencies down to around 20Hz, or 20 cycles per second. As bass frequencies go lower and lower, we are able to feel their vibrations more than we are able to actually hear them. For humans, 20Hz is roughly the point where bass ceases to be audible and can only be felt.
On the high end of the spectrum, 20kHz is about the highest pitch our ears are able to detect. 20kHz is the same as 20,000 Hertz, or 20,000 cycles per second. As frequencies go higher and higher, nearing the uppermost limit of our hearing, we are more able to hear their effect on the overall sound than we are to hear the specific frequencies themselves. These very high frequencies are often referred to as the “airy” frequencies. They are what add a sense of shimmer, openness, and clarity to the overall sound.
Frequency Range & Sound Quality
Now that you have a basic understanding of frequency response, it’s important to realize that this one factor alone does not determine sound quality. Of course, as a general rule of thumb you’ll want speakers that come as close as possible to covering your entire range of hearing. Many speakers these days are actually able to extend beyond the 20Hz-20kHz range. For example, several earbuds featured in our “Reviews” section can extend down to 10Hz, such as the Ultimate Ears 700′s, the Sennheiser IE8′s, and the Westone 4′s.
But, there are many other factors that determine how a speaker sounds. One of these very important factors is the actual frequency response curve. This is the graphical representation of how strongly a speaker reproduces frequencies within its given range. For example, a subwoofer, which is designed to pump out deep bass, may have a fairly large range of frequencies listed under “frequency response”, but it’s designed to reproduce the lowest frequencies much stronger than the higher ones.
You should never base a buying decision solely on a single specification like frequency response, but now that you have a better understanding of what this particular specification means, you will be able to make a more informed decision in the future when evaluating products. If you’re thinking about purchasing a new set earbuds, you can begin exploring our reviews by clicking here.
Tagged with: Audio Properties
Filed under: Educational