How to Test Headphones for Ultimate Sound Quality

How to Test Headphones Introduction

Since the beginning of my career, every Headphone IEM/Amp, DAP, DAC, and Amp that I received has been subject to testing under as close a variety of conditions as I could. I do this because I have many types and models of equipment. Today we test headphones for sound quality across various measures.

Subjective Headphone Testing

Headphone Packaging

I first examine the packaging and presentation. Why is it important? Does it increase the excitement? Second, how well the product has been packaged to ensure it can withstand shipping.

Headphone Accessories

Next, we will evaluate the accessories. There is a standard expectation for accessories, with any additional items being markedly more expensive. A set of earphones would require at least three sets of replacement tips in different sizes.

Manufacturers might then offer additional tips, cable management options, storage cases, or bonuses to increase their quality. (e.g., a food soft bag does not necessarily equal a good hard bag).

Headphone Build Quality and Overall Aesthetics

After I have taken care to the accessories, I look at the style and build quality of the piece. Is the piece sturdy? Are there manufacturing defects? Is it luxurious or does it feel cheap? How does it look? Are they attractive? Where would they be most at home? How durable are strain reliefs and Jack points? Etc.

Many headphones don’t last. It’s obvious from the materials used. We provide as much information as possible about the construction and whether the cables are removable.

As the earphones and IEMs are in place, we’re getting closer to the best part. I am about to check the fit. Are they comfortable? How does cable management work?

How susceptible it is to microphonics. I will also be looking at the padding’s comfort and clamping force in the case of headphones. While no two heads will be the same, it is possible to determine which headphones are best for you by actually testing them.

We look for heat buildup and how hard you put pressure on your head. We never test headphones without having used them for hours.

Headphone Acclimatization

To remove shock and minimize any perceived differences from previous equipment, the product should be used for at most 2 days. Consider this a sort of palette cleansing, before you get to the main meal.

Headphone Sound Quality Test

This is the best section and the one I will discuss the most. To this point, I have filled my notebook with about a page worth of scribbles about impressions and values gathered from the sections.

As I make my way through the critical listening playlist, these pages will be filled with detailed tasting notes.

The same tracks are always used when I listen to music. This has many benefits. The most significant is the ability to listen to the same songs repeatedly and get a feel for how they should sound.

If you notice something that is not right, it can be a red flag. This is why I recommend all enthusiasts create a playlist.

The downside? Sometimes headphones can be mediocre, but they fulfill a very specific need. Each model we review is aimed at identifying the target market, and we weigh its value. It could indicate how much value you are getting for the money you spend, or it could indicate a truly unique feature that is not available anywhere else.

Objective Headphone Testing

Noise Cancelling Headphones and Noise Isolation

We know that many people enjoy taking their headphones with them out into the world. Therefore, we feel it’s important to demonstrate how each pair of headphones or in-ears blocks noise. Some noises are not blocked equally. Advertisements can’t tell you how well headphones block sound.

The frequency response chart can be used to represent the different responses of headphones to noise.

First, we record sound with an artificial head and play some shaped noises over loudspeakers. Then, we test whether the headphones or in-ears keep sound from reaching your eardrum. We then put the headphones on our head and record another time. Once we subtract one curve from another, the data can be displayed in a manner that makes sense.

Response to Playback Frequency

Frequency response is the way that each note is highlighted in music. The majority of headphones can’t reproduce all sounds equally, so your personal physiology is also important.

The first file measures the bass extension of your headphones. The file can be played back until you hear the underlying, sweeping tone rise.

The voiceover informs you of the frequency that you have reached. This number indicates the lowest frequency at which your headphones or earbuds can extend frequency. Good headphones can reach as low as 20Hz, which is the limit of our hearing.

The second file will test your headphones’ treble extensions. The second file will measure the highest frequency of your headphones. Play back the second until you hear the underlying, high-pitched sweep tone that descends. High quality headphones can reproduce frequencies up to 20kHz, which is the maximum human hearing range.

Microphone

2021 was the year we changed to a standardized test set that played back recorded spoken phrases from a calibrated artificial tongue in our test chamber. This includes either with or without artificial background noises, simulated sound reverberant spaces, and artificial wind.

This makes it possible to compare samples of every product. It also makes it easier to make meaningful comparisons among products with respect to raw speech quality or product ability to reject noise.

Because most wireless headsets include digital signal processing (including speech processing algorithms), traditional test signals can’t provide accurate results for quantifying microphone behavior. We use ideal recordings to determine the microphone’s frequency response.

Headphone Battery life

Bluetooth headphones can be a great option for some people. However, charging the battery is a hassle. With human-like ears and testing fixtures, we can determine how long your cans can keep playing music.

The product was set up with constant playback of music. It peaks at 75dB(SPL), an enjoyable and safe listening volume. An audio waveform is recorded to show how long headphones or in-ears can last.

Although you will see results that are different from those provided by manufacturers, you can still compare them across our reviews.

Amplifier Requirements

While wired headphones are rare, sometimes they require too much power for a smartphone to work. If that happens, we’ll let you know.

We can check if the smartphone’s power output is adequate by doing some math and reading the specifications of each set of headphones. If you don’t see any section on power, you can assume everything is fine and you shouldn’t have volume problems.

Spectral Flatness

Your headphones should reproduce all frequencies evenly between the lower- and upper limits. You may not want absolute flatness, however.

Even though your hearing might not be perfect, it is possible to find headphones that are able to compensate for this. No matter how flat your headphones may be, it doesn’t really matter as long as you hear flat sound through your ears.

Frequency responses can be measured with special equipment and sine sweeps. Due to the prominent sensitivity bump at around 1-3kHz, humans have difficulty judging flatness. Frequency responses in the upper medium range are always louder because of increased hearing sensitivity. Our test tone does not consist of a continuous sweep.

It embeds an inverted hearing sensitive curve, which makes it perceptually smooth. Our compensation is only applicable to hearing threshold levels. To make the test tone as quiet as possible, turn down your computer’s volume.

If the sweep plays at your hearing thresholds, then your headphones are properly matched. If your hearing is normal, the headphones will have a flat frequency range.

Your headphones should be adjusted to match your hearing if you have poor hearing. If the test tone becomes too loud or disappears sometimes, this could indicate a problem with your hearing, or your headphones.

Dynamic Range

Dynamic range refers to the ratio between the loudest and the most audible signal. Although dynamic range isn’t part of any headphone specification it will be helpful in benchmarking the isolation offered to you by your headphone within noisy environments.

The file starts with a loud, full-scale noise. The volume in your headphones should be adjusted so that this noise can be heard clearly but not unbearably loud. After the noise, a vocal recording is made at a certain level. It is expressed as dBFS (decibels lower than full scale).

The voiceovers and noise references are alternated with each other. The volume is decreased. The file should be played until the voiceover is no longer audible. The level that the voicemail was playing when it was audible (barely) is what determines the dynamic range.

The greater the dynamic range, the better your headphones offer isolation.

Driver Matching

Better headphones have tighter tolerances for the frequency response variations of their drivers. In order to reproduce a stereo image accurately, both left and right drivers must respond equally in every frequency range. The drivers are “matched” when they meet this condition.

The driver matching test sweeps all these frequencies, up to 10 kHz, and sends exactly equal levels to both earpieces. Listen to the test tone and play it at a moderate volume.

If the panning moves away from its central position at a given frequency, it will reveal poorly matched drivers…or mismatched ears.

Harmonic Distortion Test

You will experience distortion if your headphones’ diaphragm is unable or unwilling to move at the speed required. If you’re familiar with the sound of a sine tone, distortion can easily be detected. You can try the following test if you don’t know what a sine tone should sound like.

Our test signal contains a series deformed sine tones at 125 Hz. Our test signal contains a series of 125Hz sine tones that have been intentionally distorted.

The first sine tone shows a total harmonic distortion of (THD) 5%. It has been badly damaged. The first sine tone has a total harmonic distortion (THD) of 5%. Next, listen to the files that have decreasing THD. As the distortion drops, the tone color will change and get closer to the sound of a pure sine tone.

A decrease in the THD of a test signal won’t cause any changes in sound quality beyond a point. This is the point at which the distortion you hear comes from your headphones and not the test signals.

Good headphones should have a THD of less than 0.05 and allow you to differentiate our sine tone test to 0.01%.

Binaural Test

Binaural recordings are created by placing microphones directly into one’s ears and recording the sound as it reaches the pinnae. You can ensure that the signal is received by each listener’s ears by playing the recording back using headphones. It is immersive and quite amazing, but it only works with headphones.

Our test signal is a binaural recording of a person knocking on wooden doors. If you are comparing headphones, you should judge the authenticity of the recording. Do the doors feel right next to your ears? Does it sound like real wooden doors?

How to Test Headphones: Conclusion

It is best to try headphones out yourself, and to get to know them well. Keep an open mind about the differences between the headphones. I’ve learned that the only difference between good and bad headphones is usually due to the quality of the sound.

These are the technical details of the game. It is a game in which the law of diminishing return is always-present no matter how high you go up the price scale. You can spend thousands to get to the next level. However, it is important to manage your expectations.

Beginners shouldn’t be too focused on the gear. They don’t need to rush into the first few months. The hobby is all about progression. You can experiment and build your dream gear.

Take your time when building up your knowledge. You’ll be able to appreciate the subtleties that make one piece of equipment more technical.

It should be about the music, first. Even though I have $1000 worth gear, I still love my set of buds and can still enjoy the music.

How to Test Headphones FAQ’s:

What is the importance of a headphone driver?

The driver is the main component in any pair of headphones. The driver transforms an electric signal into sound pressure. In other words, it makes the sound. There are several types of driver but they all have the same components: voice coils, magnets, and a dial.