In Ear Headphones Sound Tests
There are many different kinds of tests that in-ear headphones are taken through prior to release into the market. These sound tests incorporate a lot of technical details. So how are in-ear headphones measured technically? The graphic below gives an illustration of how Shure in-ear headphones are measured.
Frequency is measured in hertz (Hz) and intensity (dB) (source: Shure in ear headphones series)
Lets take a look at some of the components of in-ear headphones which are tested by the manufacturer to ensure optimal sound quality.
This measurement checks the bass and treble extension. If the sound is still audible at 20 Hz, then the in-ear headphones have good bass response. At 20 kHz if your ears can still capture some sound then your headphones are considered high-quality.
The Spectral Flatness and Earbud Insert Test
(Audiocheck.net has a guide how to test headphones with their soundtracks to measure the frequency response, quality, dynamic range and more)
The best case scenario is to have your in-ear headphones reproducing every frequency steadily within the lower and upper limits, with no peaks or troughs over a given frequency range. However, you do not want total flatness. Most people do not have perfect hearing, and the best in-ear headphones for anyone are those that balance out your own unique hearing curve. It’s not important for your headphones to be flat, but they should sound flat when you listen to music with them. This test is critical for in-ear headphones. Their frequency changes significantly depending on how deep you insert them in the ear, which shows how much sound is sealed in.
You may find this video useful if you are testing your headphones, continue below to see our explanation of Dynamic Range, Quality, Driver Matching and more considerations when testing your headphones.
This refers to the ratio of the loudest and the lowest sounds you are able to hear. Although dynamic range does not form part of the technical specifications of in-ear headphones, it helps in benchmarking the isolation of the in-ear headphones in a noisy place. If the dynamic range is high, then the isolation provided by the in-ear headphones will be better. Generally, “closed” and “in-ear” types of headphones offer better isolation than the “open” types and earbuds.
If you find that the in-ear headphones you have tend to rattle when you play loud or deep bass music, this is because they are either poorly built or worn out. Unless you have headphones built for bass, like the Sennheiser headphone models that have bass tuning options, you may find your cheaper earbuds come up short on the bass quality test.
Top quality in-ear headphones must have tighter tolerances when it comes to variation of the frequency response of their drivers. In order to replicate an accurate stereo image, the drivers on the right and left side have to react in tandem to every frequency in the audio range. If this happens, then we can say that the drivers are “matched”.
When it comes to the wiring of in-ear headphones, those that are wired properly will move the left channel to the left earpiece and the right channel to the right earpiece. Furthermore, comparative polarity has to be maintained. If the same input signal is received by both drivers, they should route it in the same direction.
Binaural recordings are created by inserting microphones into a person’s ear and recording the sound that is received by the ear. The recording is then played back via in-ear headphones to make sure that both ears receive the exact same signal as the one initially recorded.
In the end, the best sound test you can employ for your in-ear headphones is to listen to your favorite music.