One of the drawbacks of mankind’s inventions is that the products need to be “warmed up” before it can perform optimally. A perfect example that we all can relate with? A car! The car engine has to be turned on for it to work for a few minutes for it to pick up. When it comes to Headphones, it has been noticed that some headphones do not produce excellent sound quality until after some hours.
Audiophiles (a term used to describe people that are extremely interested in music and sound quality) agree with this statement that headphones need to be “warmed up” for a bit before it “picks up” in the sound production.
This “warming up” process in sound engineering is called Burning In. Many sound equipment (e.g., Amplifiers, Speakers, Hi-Fi, and Sound Systems) need to be warmed up before use.
1. Burn-in Headphones with Pink noise & White noise
A lot of manufacturers do not indicate that the headphones they produce need a warm-up, and this is why some users think they need to “adjust the sound” of the headphones when they just turn it on. The truth is because headphones work on the principle of electromagnetism, they might lose some charge(s) when they have not been in use for a while. The justification for this also has to do with the overlapping of sound waves, diffusing of waves, and so on. This is because some headphones play certain sounds in certain frequencies that might allow an increase in the diffusing of the waves. Some manufacturers, on the other hand, recommend that headphones need to be warmed up.
Warming up a piece of sound equipment depends on some factors, for example, time, warm-up method, etc. Usually, the changes that happen during the warm-up of the headphones are not detected. This is because the ear cannot pick up the changes in such frequency as well as other characteristics of soundwaves such as Frequency Sensitivity. Changes in soundwaves can also be caused by external conditions such as humidity, temperature, etc. These external changes are also not noticed by the ear. You can measure the changes in frequency response using the eardrum in a method called Head Related Transfer Function. This is because of the vibrations between the sound transmitted by the headphones and the ear. The HRT function is the difference between the flat sounds in the free field and the sound that enters the eardrum when the head is in the free field range. It should be noted that flat sound is no longer flat when it enters the eardrum, which is why the measurement of the HRT function must be done in a free field. It is important to use the headphones in a number of different positions to get the true measurement of the acoustic energy being transmitted from the headphones. This is called Spatial Averaging.
The burning-in process can also be tested using a single-blind test where a headphone is tested against a standard headphone that has gone through the burning-in process and is producing a good sound quality. It is a blind test because the headphone specifications are not indicated, and the warm-up in the period is not yet known. So the person testing the headphones has no idea what to expect until the burning in the process is over. When the headphone being tested is done with the burning in process, the results are checked with the same results of a different burn-in test of a headphone with the same specifications.
Burn-in times for mechanical products range from 10 hours to over 100 hours, although this period should not be entirely continuous. The break-in times should be measured from minutes to hours. The drivers of headphones become flexible after use and change the sound they produce. A lot of people believe that warming up improves headphone sounds and makes them deliver the sound they produce for the life of their use, while some sound companies argue that this is not true.
2. How to warm-up Headphones
There is no standard method of warm-up headphones. But there are a lot of methods that have been used, and they have been known to be tested and trusted. Some of the tips are;
- First, prepare a burn-in playlist. A burn-in playlist is simply a list of songs that has different wave frequencies, sound with high frequencies, low frequencies, and mid-wave frequencies. This playlist must be at least up to 40 hours and can last up to 100 hours. This is because the aim of this playlist is to make the drivers loosen up enough to play sounds at different frequencies at an optimal level. This playlist should have music within different genres like Classical, Country, R&B, Hip Hop, Rock, Heavy Metal, and even Rap Music. Also, the audio files used to create the playlist must have a mixture of noises, both white and pink. White noise is a constant background noise of different frequencies with equal intensities, while pink noise is the term used to describe a sound with low frequencies that have equal energy.
You can also use an app on your system to create the burn-in playlist, and you can file the audio according to the genre. To make things easier, you can download an online burn-in file which is available online and can even be downloaded without an internet connection. There are even apps with audio files for burn-in built-in headphones.
- Next, you need to set up the audio files and connect your headphones. It is advisable that you use wired headphones because wireless headphones do not have a good battery life, causing interruptions and not producing clear sounds due to Bluetooth technology. Wired headphones are, therefore, the best bet for warming up. You can also use an MP3 Player for warm-up. Listen periodically to the playlist. First, listen to make sure that your headphones are playing sounds, then you can now listen closely to the sound quality of the music playing.
It takes a longer time to get the quality of the sound playing. If you are a sound engineer, you can also jot your findings now to make a comparison. Most headphones start producing excellent sound quality from about 50 hours upwards. You will need to check the peripherals like if the Aux-In cord of the headphone is not damaged and plugged in properly. Also, check the volume of the system and the headphones. If the headphones are too low, you might not be able to detect the sound quality. However, if the volume is too high, you stand the risk of damaging your headphones.
- Play the burn-in playlist continuously. The recommended time for warming up your high-quality headphones is 40 hours and above, but this can cause great damage to your headphones if you play the burn-in songs at once. It is therefore preferable that you play your burn-in songs for a few hours over a period of days to gently “warm-up” both the headphones and the diaphragm. Now, it is important to care for your ears in the process of warming your headphones. Do not wear your headphones throughout the burn-in process. Ideally, you should leave the headphones for a while and only wear them from time to time to check for any improvement in the sound quality. Depending on the type of headphones, the time for warming-up differs. Some headphones require as little as 80 minutes of warm-up time, while some high-quality headphones can take up to 100 hours of warm-up time.
3. A few other tips to note when warming up your headphones
- It is recommended that you put a playlist that sounds like the music you would normally listen to. This will also have music that has white noise, pink noise, and audio files with different frequencies.
- Plan periods of silence between audio files as this will help the headphone drivers to rest after a prolonged time of silence.
- Do not worry about periods when the headphones do not sound so great. It is quite normal and should not discourage you from warming up in the process.
- You can decide to stop the burn-in process at any time you like. This should not affect your headphones at any time.
- Warm-up as a process works best with wired headphones that are over the ear or on the ear designs. Other designs (e.g., IEMs and Earbuds) may also benefit from warm-up even though it will be minimal. The material used in headphone production is also designed to help an optimal experience. For example, the earpads used in making headphones are viscoelastic, a property that allows the headphone to expand and contract in order to resist force. This is why a lot of headphones using relaxed earpads will fit better to allow the movement of sound movement. The ear pads also allow sealing the sounds within the ear, preventing noise isolation, and ensuring that the headphones sound better.
- An extra tip for warming-up headphones? Just use your headphones to start playing music from the time you buy them. The music you play (shuffled audio files) contains different frequencies, which is also a warming-up method. After a while, the sound quality of the headphones will pick up naturally.
So to answer the question, you do not need to warm up your headphones through a strict warm-up process. If you are using a high-quality headphone and you need top-notch sound quality, you might need to warm up your headphones!
