How does the Sennheiser CX 400BT earphone perform?

As one of the four giants of earphones, Sennheiser’s strong technical strength and pursuit of details in the audio field are well-known for audiophiles. With the increasing popularity of wireless Bluetooth headsets, as the headphone industry leader, Sennheiser has recently not only updated the second generation of highly popular MOMENTUM series but also launched the young and fashionable Sennheiser CX 400BT wireless earphone.


The white main color of the outer packaging of Sennheiser CX 400BT earphones is combined with the traditional blue color of Sennheiser as the auxiliary color. It is relatively fresh at a glance.




It is reported that when the Sennheiser CX 400BT true wireless earphone is fully charged, it can have almost 7 hours of performance, and it can last up to 20 hours with the charging bay.



The more humane thing is that there is a switch on the charging compartment, and you can see how much power there is in the charging compartment by pressing it.




Sennheiser CX400BT adopts an ergonomic design for our auricles. When actually worn, it fits our auricles very well and is comfortable when worn. In addition, the in-ear earphone design has a good sound insulation effect.



The weight of a single earphone is only 6g and the weight of the charging box is only 37g, which is relatively light regardless of whether it is worn or carried.


The current wireless Bluetooth headsets basically support touch operations, but there are not many touch operations that can be customized. Sennheiser CX400BT is one of them. There is a distinction between left and right earbuds. The left earbud mainly controls music, such as playing and pausing music, switching up and down tracks, and reducing the volume, the right earbud mainly controls the functions of the earphone, such as activating the voice assistant, making and receiving calls, increasing the volume, and so on.



The custom setting of touch operation is mainly realized through the smart APP custom modification. On the APP, we can customize and set the touch interaction method according to our own usage habits. In addition, Sennheiser not only marked the left and right ears with English letters on the earphone but also added 2 magnetic contact points on the basis of the charging electrode. When the earphone is placed in the charging compartment, it will naturally attract and fix 2 earphones.



During my actual use, I found that the noise reduction and sound insulation function of this earphone are quite good. Mainly due to its ergonomic in-ear earphone design, its passive sound insulation effect is very good, as well as up to 5 pickup holes on the earphone, plus its beamforming technology. Whether it is for voice calls on the street or for listening to songs on the noisy subway, Sennheiser CX400BT can give me a high-definition call environment and pure music enjoyment.



Sennheiser CX400BT supports connecting after opening the cover. When the earphone is taken out of the charging compartment, it will automatically connect to the previously connected audio device. Thanks to its Bluetooth 5.1 chip, it has a stable wireless connection experience within 10 meters, and it can also transmit high-quality music in my HiFi player to the earphone in HD. CX400BT supports HD encoding and decoding technologies such as AAC and aptX.


For Sennheiser, sound quality is certainly its strength. This time Sennheiser equipped a 7mm micro-motion dynamic unit in the CX400BT small cavity earphone, which has a frequency response range of 5-21kHz, a signal-to-noise ratio of 107dB, and a total harmonic distortion of less than 0.08%.