Sony MDR IF140K Specifications, Tests and Review

​​The Sony MDR IF140K are wireless headphones. The wireless connection allows absolute freedom of movement and with that increases the comfort of using the headphones. This feature is very popular, especially when using headphones every day. The limiting factor of wireless headphones is a certain delay in the sound transmission between the source and the headphones (almost indistinguishable for a normal user), as well as the need to charge them (in the case of wired headphones, the headphones are recharged by connecting the cable itself). The transmission range offered is up to 7 m. The maximum range represents the maximum distance from the audio transmission source that the headphones can be used for wireless audio transmission. However, the maximum communication range can be affected by obstacles such as people, walls, etc.

The headphones are designed as on-ear. On-ear headphones are generally lighter. However, their design has fewer isolation capabilities, and therefore, for example, more sound can be let in and out compared to around-ear headphones. The weight of the headphones is 75 g.

The sound quality can be affected by many factors. When it comes to frequency range, the wider it is, the more detail you will hear when listening. However, the range a person can perceive is highly individual. The average person is able to perceive frequencies in the range of 16 to 20 000 Hz. So the most common frequency range you will see on the market is 20 to 20,000 Hz. Lower frequencies up to approximately 256 Hz are considered bass frequencies. Therefore, the lower the bottom value is, the better the headphones will reproduce bass. Conversely, values from approximately 2 048 Hz upwards are treble. That is why headphones with a high upper value will provide a much more accurate reproduction of high notes. Sony MDR IF140K offers a frequency range of 18 - 22000 Hz.

The device connected to the headphones also plays a role most times. The lower impedance value (approximately 100 to 150 Ohms) is suitable for playback from mobile phones, laptops or other portable players that do not have a powerful enough amplifier. The lower impedance will ensure that the required volume level is achieved with less power, thus extending the life of the player. However, at the same time, with lower impedance, there is more distortion of the sound. Headphones with a higher impedance of around 250 Ohms and above are then more suitable for playback from really powerful signal sources or using a headphone amplifier, otherwise the sound coming out of them might not be loud enough. At the same time, higher-impedance headphones will also ensure less distortion in the sound. In the case of these headphones, the impedance reaches the 16 Ohm value.

An important part of these headphones is the diaphragm, which, simply put, converts the electrical signal into a sound. The thin diaphragm that is around 6 mm thick can react quickly to changes in the audio signal and improves high-frequency listening. However, it is less sensitive to bass. The medium-thick diaphragm of around 10 mm provides a fairly balanced sound profile, allowing you to enjoy both bass and treble. A thicker diaphragm of around 20 mm cannot react so quickly to changes in the sound signal, thus impairing bass listening. However, it is more sensitive to higher frequencies. This model features the PET - 30 mm.

In terms of headphone battery life as a significant factor in the purchase decision, it depends on what you want to use the headphones for and potentially how often you will be able to recharge them. Headphones with up to a few hours of battery life are more suitable for home use as they will require more frequent charging. Headphones with a battery life of around 10 hours or more are already more suitable for commuting and shorter journeys. However, nowadays you can also find headphones on the market that have a battery life in the higher tens to hundreds of hours. In this case, you do not have to worry about your headphones simply running out of power on longer journeys, and you will not have to deal with constant recharging. The battery life of the Sony MDR IF140K reaches up to 60 hour(s).