Powerful mini sound

Until a certain moment, small plug-in or in-ear headphones (especially wireless ones) caused mostly skepticism among music lovers. Where are these crumbs to solid full-size headphones with huge cups and thick wires! Indeed, true Hi-Fi sound for the ultra-light class, especially in the wireless version, was completely unattainable at first. But times are changing, new technologies are emerging, and now we are seriously talking about powerful bass, soundstage, and attack testing when it comes to the smallest form factor.

The German company Sennheiser is perhaps one of the first brands that we remember when it comes to quality headphones. This company is not only a keeper of traditions, but also a pioneer of innovations in the field of equipment for sound recording and reproduction. Sennheiser CX 400BT True Wireless in-ear headphones demonstrate how high-quality sound can be, even if we are not chained to an amplifier by a cable, but carelessly walk around the city.

This model uses a truly revolutionary innovation – Sennheiser’s True Response progressive sounder. With a 7mm diaphragm, this full-range speaker is one of the smallest in the world. If you are not familiar with the word “broadband”, let us explain. Full-size loudspeakers use multiple speakers per stereo channel – usually three or two. Special electronic filters separate the incoming signal by frequencies: the largest speaker “bass”, the smallest one produces high ringing sounds, the middle is given to a mid-range loudspeaker. Surprisingly, manufacturers of in-ear headphones sometimes take the same approach, placing an entire system of radiators in each earphone. But the broadband Sennheiser True Response single-handedly reproduces the entire range available to the human ear, while providing high detail and crystal clear sound. At the same time, it is possible to avoid interference that occurs at the intersection of the “zones of responsibility” of different speakers, which degrades the sound. Another feature is a two-chamber absorber. This device allows you to smooth out sharp jumps in volume, which are often poorly processed by the speaker and cause distortion. Headphone emitterThe CX 400BT True Wireless handles these peaks beautifully, and the sound remains detailed and clear.

The BT index stands for Bluetooth. As everyone knows, this is a popular short-range wireless data transfer protocol, often used in gadgets and household devices. The absence of wires between the headphones is, of course, a blessing, but the bandwidth of the Bluetooth-based channel is obviously lower than the wired one. The less data is transmitted per unit of time, the worse the quality of the reproduced sound. And that was one of the obstacles to the emergence of Hi-Fi in wireless headphones. The situation was saved by the introduction of progressive audio codecs such as aptX and AAC. Codecs are programs built on algorithms for compressing audio files. Their function is to prepare audio data for transmission in the most compact form (taking into account the narrowness of the radio channel) and subsequent restoration with a minimum loss of the original sound quality.

I must say that now in the field of portable audio processes are taking place, reminiscent of the modern evolution of digital photography. Smartphones with a small sensor and tiny bead lenses produce pictures that rival professional cameras in quality. All this is thanks to the progressive software, which “extra calculates”, completes, refines the original picture, bringing it closer to the ideal. Codecs and other software can also improve the original sound or optimize it for the listener’s taste. Sennheiser’s headphone set also includes a virtual element – a special smartphone app that lets you work on the sound and functions of the headphones. 

However, the app isn’t the only way. There are sensory zones on the outer surface of the headphones. The uncomplicated “touch language” allows you to control and listen to music, and the now obligatory functions of a telephone headset. 

Another component of high-quality audio in portable audio is isolation from ambient noise. The  CX 400BT True Wireless uses passive noise cancellation. It is based on the isolation of the ear canal from extraneous sounds. For in-ear headphones, a snug fit and proper positioning is of the utmost importance. Therefore, the set includes ear pads in four sizes, allowing you to perfectly fit the headphones to any structural features of the ear canal.

True Wireless translates into Russian as “true wireless”. Such a term may cause confusion: there are wires – it is clear, there are no wires – it is clear, but what is the truth there? The thing is that initially the radio signal receiving device was located only in one of the Bluetooth headphones. To the second earpiece, the signal went through a wire that had to be worn around the neck. Such a wire can look very aesthetically pleasing – like a kind of tie of the Hi-Tech era, but not everyone seems comfortable with this option, especially if a person leads an active lifestyle. True Wireless technology has solved this problem. From now on, each earphone is a full-fledged device for communication with a player (smartphone, player), independently receives and processes the signal.

True Wireless headphones have only one big problem: These devices, the size of small grapes, are easy to lose. After all, there are no wires behind them. Failure, roll up or fall out of your pocket imperceptibly – that’s all about them. But every cloud has a silver lining! An ingenious solution was invented – a special hard case that simultaneously serves as a power bank. The case is much more difficult to lose, and while the headphones are inside, they recharge. The  CX 400BT True Wireless has such a case, and therefore they work without recharging for 7 hours, and an additional 13 hours of music will give you a pre-charged case. A total of 20 hours of autonomy without power outlets and USB sockets

What’s the secret to the fact that Sennheiser has been able to bring products to the market that incorporate virtually all of the latest gimmicks, but still focus on sound quality? Perhaps the answer needs to be sought in the company’s success story, which would have been impossible without a deep understanding of the nature of sound and vast experience in the music industry. The company was founded in 1945 by Fritz Sennheiser and is still a family business today.

It’s easy to see that Sennheiser isn’t just about headphones. Behind each of the company’s products, even those aimed at the average consumer, there is a varied experience, expertise in the field of sound – from recording to playback. And of course, the feeling of beauty.