Astrum ET240 Specifications, Tests and Review

The wireless headphones Astrum ET240 allow unrestricted movement, which increases the comfort of using the headphones. This feature is particularly popular with headphones for casual use. However, a certain limiting factor of wireless headphones compared to wired ones is a certain delay in sound transmission between the source and the headphones (but almost indistinguishable for the average user) and the need for regular charging. Unlike wired headphones, wireless headphones are charged separately. The headphones use the Bluetooth 4.0 technology for sound transmission. The transmission range offered is up to 10 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 in-ear headphones, which are inserted inside the ear to provide more or less isolation from ambient noise. The level of isolation may vary depending on whether the ambient noise isolation feature is present or not. One of the main advantages of these headphones compared to over-the-head ones is their stackability and easy portability.

The sound quality can be affected by many factors.

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 32 Ohm value.

The headphones are composed of many various components, one of the most important is the diaphragm. Diaphragm transforms the electrical signal into sound and therefore its quality affects the overall listening experience. There are three types of diaphragms: thin, medium-thick, and thicker. A thin 6 mm thick diaphragm responds quickly to high frequencies but less sensitively to bass. The medium-thick 10 mm diaphragm provides a balanced sound profile, allowing you to enjoy both bass and treble. The thicker 20 mm diaphragm is more sensitive to higher frequencies but has a poorer bass response. These headphones are equipped with the 10 mm.

The microphone sensitivity is -42 dB. A lower microphone sensitivity will generally ensure that even quieter sounds are caught. On the other hand, in noisier environments, distortion of the recording may occur. With a higher sensitivity, the microphone will not distort the recording even in noisy environments. On the other hand, the microphone will not pick up quieter sounds. So it depends on the environment and the purposes you plan to use the headphones for.

These headphones have a battery capacity of 60 mAh. 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 Astrum ET240 reaches up to 5.5 hour(s).