EPOS I SENNHEISER HD 25 Specifications, Tests and Review

The EPOS I SENNHEISER HD 25 are wired headphones. In the case of studio and professional DJ headphones, a wired connection is a standard and a necessity. In this case, connecting via cable reduces audio transmission delays and prevents unwanted battery drain as it would be in case of wireless headphones. The same is de facto true for gaming headsets. In case of headphones for normal music listening, the cable is rather a relic, although it still has its fans. However, the wireless option is much more popular for everyday use in today’s world.

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 140 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. EPOS I SENNHEISER HD 25 offers a frequency range of 16 - 22000 Hz. Overall, these headphones can reproduce sound up to 120 dB. However, be careful. Repeatedly playing music continuously at really high volumes can damage your hearing.

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 70 Ohm value. The maximum input power of these headphones indicates how many decibels they can receive from the device without any damage. For EPOS I SENNHEISER HD 25, it is 200 mW. Total harmonic distortion is one of the parameters you will come across and usually includes the average value of the distortion when reproducing all frequency bands. This parameter is not critical when choosing headphones, but it is important to remember that higher harmonic distortion can negatively affect sound quality. In case of these headphones, the total harmonic distortion is Audio Output | Total Harmonic Distortion.

The design of the headphones and their ear cups can also affect the quality of the audio output. The closed design does not allow ambient noise or sound from the headphones to flow outwards. Not only will you enjoy music in noisy environments, but you won't disturb anyone while enjoying listening session. The closed-back design makes the headphones suitable for the office or for travel.