[User experience] Audio-Technica ANC7b - full immersion

Do you like silence? - And I love. How much is not even silence itself, but the absence of external stimuli. During study, work, you need to focus on the problem / task to be solved, and it’s quite difficult to do it when the household is dancing around the household or the telephone is broken throughout the office ... Of course, there are such moments when you boil over with special passion when you are already attracted to process and nothing can distract you. But what to do when there is no particular desire to do the work, and here it is impossible to concentrate? For myself, I found a way out in the face of headphones with an active noise reduction system.

Let's start with the fact that I first learned about headphones with an active noise reduction system after reading
of this post , where habrazhiteli actively shared photos and discussed their jobs. The author of this thread mentioned quite expensive Bose QC-15 headphones (~ $ 500 in the CIS), so the operation was launched to search for cheaper alternatives. As a result, the choice fell on Audio-Technica ANC7b - headphones from a well-known Japanese manufacturer that has proven itself worldwide.

▐ Specifications

Emitter	Dynamic (Neodymium, 40 mm)
frequency range	10 Hz - 25 kHz
Noise reduction level	up to 20 dB
Impedance	300 ohm
Sensitivity	109 dB / mW
Cable	1.6 m (removable)
Plug	3.5 mm
Body material	Plastic
Type of ear cushions	Monitor
Acoustic design	Closed
Weight	210 g (without cord and battery)

It would be logical to continue the article describing the packaging and delivery of the monitored device, but due to frequent moves in the past six months, all the equipment was lost and only the headphones and the box remained. Initially, one could find in the latter: a hard transport case (I have no idea where I profiled it), a removable cable (similarly), an AAA battery, an adapter for using headphones in airplanes + a 6.3-mm adapter and a pair of interchangeable cables (with microphone and without).

That only the complete case cost ... Well, okay, let's not talk about sad things, for the last few months I have been using headphones with a Philips cable, which was ~~brazenly wrung out~~ politely by the user dcoder_mm . On occasion, I say hello and pledge to return the cable ;)

Design, construction, wearing comfort

When I first met, Audio-Technica ANC7b headphones did not make any vivid impressions on me. Austere design due to the use of plastic materials in the case, the classic shape with arc fastening, small creaks when bending the headphones and turning the cups. The latter have two degrees of freedom: a rotation of 90 degrees on the vertical axis and 45 on the horizontal.

The headband size adjustment mechanism has 15 positions in 3 mm increments. There are no designations, so it is assumed that the user must once set the desired size or each time be guided by clicks that publish guides when resizing.

Headphone cups are of medium size (relative to other overhead monitors). By tradition, the manufacturer’s logo, headphone model and “left-right” marking are located on the outside.

The microphones at the bottom of the cups are part of the active noise cancellation system. This also brought the battery compartment, which is hidden behind the false panel. Any AAA batteries with voltage up to 1.5 V.

On the left "ear", in addition to the elements already mentioned, there is an ACP system switch. The activation of the latter is signaled by a bright blue ~~highlight~~ LED. There is also a connector for connecting a 3.5 mm audio cable, but it is worth noting that a plug with a larger diameter may not fit into this port.

By the way, on the axis connecting the right cup with the headband there is a small relief point, thanks to which you can blindly determine where the right and where the left "ear."

The ear cushions are medium in size, moderately resilient, as well as the headband covered with leatherette. Headphones tightly wrap their heads, but it does not cause any inconvenience.

As for my personal impressions about convenience, I write these lines after 5 (and maybe even more) hours of being in headphones. Overboard the winter, in a room around 20 degrees - ears in comfort. In the summer, of course, there is a slight discomfort, since the ears are sweating, but on the other hand - show me headphones in which your ears will remain dry in the thirty-degree heat?

▐ Sound, compatibility, some aspects of operation

First, do not be afraid of 300 ohm resistance. First, this is an indicator when the ACP system is off. Unfortunately, the manufacturer did not provide the value of this parameter with the “noise level” turned on, but judging by the change in the volume level, a rather “cheerful” amplifier is built into the headphones.

Secondly, given the sensitivity of 109 dB / mW, even with the proprietary technology turned off, headphones can be used in tandem with a smartphone or player. But here it is worth considering that there will be no volume reserve. So, even for the usual listening to music, you have to turn the volume to maximum. And in general, for comfortable listening to music in these headphones without “noise” you should get a more serious source, for example - FiiO E10 .

Frequency response

As for the very quality of the sound, which in fact is a concept of purely subjective and ideally listening to IRL headphones before buying, the sound is a bit more than satisfactory for me. I use headphones mostly at home, paired with an external DAC, so in both modes I don’t feel a lack of volume. And I use it quite often - at least 3-5 hours a day and often with noise cancellation turned on (+ sounds of nailing nature or light music). Such a set makes it possible to completely disengage from the roar of the old man of the refrigerator, the conversations of the roommates and the movements of them around the room. At the same time, louder conversations are leaking, which is a plus for me personally.

If it were not for such enormous sizes (on my small head and so far such headphones look very pitiful), then I would gladly ride with these headphones on the subway. The bottom line is that the ACP best copes with the lower frequencies, i.e. the subway hum cuts off completely, and the female voice announcing the station remains audible (provided you listen to an audiobook / podcast or music at low volume). Here, one of the main drawbacks was noticed: due to the use of active electronics, the device has the ability to catch pickups from mobile phones, albeit periodically, but this effect causes some discomfort.
')

▐ Device active noise reduction system

And what exactly is the noise reduction system? First you need to understand that noise reduction is both active and passive . The latter is mainly the prerogative of closed monitor headphones. Cases of cups of such devices do not contain any openings from the outside, and the walls of such headphones are usually quite massive and the material from which they are made often has the ability to dampen sound vibrations. Headphones with the best passive noise cancellation have indicators of 35-37 dB.

Active noise cancellation, in turn, requires the introduction of electronics into the headphones. The principle of operation of this system is quite simple to understand, even if you skipped physics lessons at school. Sound is a physical phenomenon that represents the propagation of elastic waves in a particular medium. More precisely, the sound is a wave. The music, the roar of the jackhammer, the cries of the baby - all these are sound waves that we encounter everywhere. One of the main phenomena inherent in the waves is interference.

Wave interference - the mutual increase or decrease of the resulting amplitude of two or more coherent waves when they are superimposed on each other. (c) Wikipedia

But how does the active noise cancellation system depend on the interference phenomenon? - And so that this method of noise reduction is based on interference! If the waves come to the point of the medium (occur) in antiphase, then the displacement of the particles will be multidirectional, which leads to a decrease in the amplitude of oscillations, i.e. sound vibrations coming from the outside are extinguished. Due to limitations (possibly temporal, because progress does not stand still), the “shumodava” imposed by internal electronics cannot fully compensate external noise, unfortunately, is not possible.

This is how the ACP system works. Special microphones, which are located in the headphone cups, pick up external sounds, and the built-in electronics invert them and add to the music being played, thereby removing external noises.

▐ Insides , autonomy

Recently, it is fashionable to rate devices for their maintainability, in order to keep up with the trends, we will prepare headphones, and at the same time we will see what kind of magic is hidden in the body of these. Peel off ear cushions:

Under a thin foam filter (not in the photo) there is an ACP microphone and a dynamic radiator. For surround sound, the headphone cups are filled with foam.

Once again we see that the headphone case is entirely made of plastic. On the left cup there are three screws under the screwdriver CR-VT8 - they hold the false-panel under which the electronics of the active noise cancellation system is hidden.

Further, more: the oval-shaped printed circuit board (by clicking on the image below - full size) occupies almost all the internal space of the left cup. Dirt around the audio jack slightly spoils the impression, but in general everything is fine.

On the reverse side are two single electrolytic capacitors and a standard 3.5 mm TRS connector.

In the production of these headphones, serial components were used, for example, the octopus chip on the right side of the board is the MAX660, a voltage inverter, which can serve both as a source of negative voltage and as a boost converter for the amplifier. In the upper left corner - ST V324 (14 pins) - a four-channel amplifier with a THD (nonlinear distortion coefficient) of not more than 0.01%. Unfortunately, the appointment of the MS located above has not been established. And yes, I later replaced the blue LED with a ~~warm~~ yellow ~~lamp~~ .

A few words about autonomy. I use an AAA Ni-MH battery for the ACP system. As you already know in headphones, I spend ~ 2-3 hours a day, respectively, the 700 mAh battery is charged once every two weeks. I did not like the absence of any charge indicator - you can only find out about the dead battery only by periodically snoring in the ears, accompanied by a slow attenuation of the LED. I also advise you to follow the shutdown of noise reduction, because no auto-off function was detected.

▐ Price, totals

Audio-Technica ANC7b - excellent closed-type headphones with an active noise reduction system. For its main task - to cut off external noise copes relatively well. Despite the modest design and cheap materials of the case, the headphones are well assembled, have a comfortable fit and decent sound. Of the main flaws, there are: the absence of a charge indicator, periodic pickups from cell phones ... The price, both in the world and in the CIS market, fluctuates around 5-7 thousand rubles (140 - 190 dollars).