Audio delay
Sound delay in wireless headphones is a natural process caused by the specifics of audio data transmission over Bluetooth. It can be either almost imperceptible or clearly interfere with comfortable gameplay or watching video content. This paragraph provides the declared sound delay time in milliseconds, which is written in the technical specifications for a particular headphone model.
Power
Headphone power is expressed in milliwatts (mW) - this figure can vary from a modest figure of 1 mW to an impressive level of 5000 mW. For the vast majority of headphones, power is not a decisive factor. In essence, this is an indicator of how loud the sound can be without the risk of damaging the drivers. At the same time, the parameter is important for some professional studio and audiophile models - in this case, power means the maximum audio signal level that is allowed to be supplied to the headphones from the sound source. If the headphones are used with a device that supplies too strong a signal, they may distort the sound or fail.
Frequency range
The range of sound frequencies that headphones can reproduce.
The
wider this range, the more fully the headphones reproduce the spectrum of sound frequencies, the lower the likelihood that too low or too high frequencies will be inaccessible. However, there are some nuances to consider here. First of all, let us remind you that the perceptual range of the human ear is on average from 16 Hz to 22 kHz, and for the complete picture it is enough for headphones to cover this range. However, modern models can significantly exceed these boundaries: in many devices the lower threshold
does not exceed 15 Hz, or even
10 Hz, and the upper limit can reach
25 kHz,
30 kHz and even
more. Such wide ranges in themselves do not provide practical advantages, but they usually indicate a high class of headphones, and are sometimes given only for advertising purposes.
The second important point is that a wide frequency range in itself is not a guarantee of good sound: sound quality also depends on a number of parameters, primarily the amplitude-frequency response of the headphones.
Emitter type
The type of sound emitters installed in the headphones. The type determines the principle of operation of emitters and some features of their design.
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Dynamic. The simplest type of emitters operating on the principle of an electromagnet. Due to the combination of low cost with quite decent performance, it is also the most common, especially among entry-level and mid-range headphones. Such an emitter consists of a magnet, a coil placed in its field, and a membrane attached to the coil. When an alternating current (signal) enters the coil, it begins to vibrate, transmitting vibrations to the membrane and creating sound. From an acoustic point of view, the main advantages of dynamic radiators are a wide frequency range and good volume, the disadvantage is a relatively high probability of distortion, especially with a worn membrane.
—
Reinforcing. A peculiar modification of dynamic emitters (see the relevant paragraph), used mainly in high-end in-ear headphones. The basis of the design of such a radiator is a U-shaped metal plate. One of its ends is fixed motionless, the second, movable, is located between the poles of a permanent magnet, and a coil is wound around it (closer to the crossbar), through which the signal current passes. Vibrating under the action of this current, the movable part of the plate transmits vibrations to a rigid membrane, with which it is connected by a thin need
...le. This technology allows you to achieve good volume and low distortion with a very small size of the earpiece itself. The disadvantages of reinforcing radiators, in addition to high cost, are uneven frequency response and a relatively narrow frequency range. However, in expensive headphones of this type, several emitters can be provided at once, including on a hybrid basis (see relevant paragraph).
— Hybrid. Hybrid devices are usually called devices that combine dynamic and reinforcing emitters. See above for more details on these varieties; and their combination is used to combine advantages and compensate for disadvantages. Usually, in such headphones there is only one dynamic emitter, it is responsible for low frequencies, and there can be several reinforcing ones, they share the midrange and high frequencies. This allows you to achieve a more uniform frequency response than in purely armature models, but it significantly affects the price.
— Planar. The design of emitters of this type includes two powerful permanent magnets, between which there is a thin film membrane. The shape of the headphones themselves can be either round (orthodynamic emitters) or rectangular (isodynamic). According to the principle of operation, such systems are similar to dynamic ones, with the adjustment for the fact that there is no coil in the design — its role is played by the membrane itself with applied conductive tracks, to which the audio signal is fed. Due to this, distortions associated with the uneven oscillations of the membrane are practically absent; in addition, the sound as a whole is clear and reliable, and the frequency response is uniform. The main disadvantages of planar magnetic headphones are high cost, increased requirements for signal quality, and rather large dimensions. In addition, they are somewhat inferior to dynamic ones in terms of volume and overall frequency range.
— Electrostatic. Like planar-magnetic (see the relevant paragraph), such emitters are designed according to the "sandwich" principle. However, the membrane in them is located not between the magnets, but between the metal grids, and is made of a very thin metallized film. An audio signal is connected to such a system in a special way, and the membrane begins to oscillate due to attraction and repulsion from the grids, creating sound. Electrostatic drivers achieve very high sound quality, low distortion, and high fidelity, but they are bulky, complex, and expensive to use. And it's not just the high cost of the headphones themselves — their operation requires additional matching amplifiers with a voltage range of hundreds or even thousands of volts, and such devices cost a lot, and have the appropriate dimensions.Sensitivity
The sensitivity of the headphone's own microphone.
The more sensitive the microphone, the higher the signal level from it, at the same sound volume, and the better this model is suitable for picking up quiet sounds. Conversely, low sensitivity filters out background noise. At the same time, we note that these nuances are important mainly in professional work with sound. And for simple tasks like voice communication over the phone or via the Internet, sensitivity does not really matter: in headphones of this specialization, it is selected in such a way as to ensure that the microphone is guaranteed to work.
Mobile app
The ability to operate the functions and settings of headphones through
a mobile application for a smartphone or tablet. Communication between the device and gadgets is usually carried out via the Bluetooth wireless protocol. The mobile application may provide tools for flexible sound settings (equalizer, bass boost, etc.), switching noise reduction and transparency modes, reassigning buttons and gestures, finding lost headphones, etc. Also, the ability to update the headphone firmware is often implemented through the mobile application.
Volume control
The headphones have their own
volume control. Such a regulator can be placed both on the wire and on one of the cups (the latter is typical for wireless models). Anyway, this function allows you to easily adjust the volume: for this you do not need to go into the computer settings, press the buttons on the player or smartphone, etc., just use the control at hand. On the other hand, additional equipment complicates and increases the cost of the design, and also increases the likelihood of distortion. In light of the latter, volume control is almost never found in professional headphones.
Autopause
A function that allows you to automatically pause the playback track when you remove the headphones (or one headphone).
Autopause is found mainly in wireless models (see "Connection Type") true wireless format (see "Cable Type"); however, there are other types of headphones with this function — for example, with a combined connection and an overhead design. Anyway, the proximity sensor is usually responsible for the auto-pause operation, which is triggered when the earpiece moves away from the ear. This feature is especially useful in situations where, after removing the headphones, there is no time to manually pause playback — for example, you need to urgently respond to what is happening nearby. At the same time, some models are able to automatically resume playback when the earpiece is returned to its place, however, this function is not strictly required — it will not hurt to clarify its presence separately.
Noise cancellation
A system that reduces the influence of ambient noise on the audibility of sound through headphones. "Noise reduction" with the help of a separate microphone (or several micro) "listens" to external sounds and sends the same sounds to the headphones, but in antiphase. Due to this, the noise heard by the ears is attenuated almost to zero and the user can enjoy the sound of the headphones without interference even in a rather “loud” environment. For filtering in headphones, Active Noise Cancellation (ANC) and Environment Noise Cancellation (ENC) systems are used. The first suppresses all the noise around the listener, the second - reduces the noise level of the environment.
Active noise cancellation affects the purity of the sound, but the noise from the outside spoils the picture when listening to audio tracks even more.
Also in the headphones there is an adaptive active noise reduction system Adaptive ANC, aimed at automatically adjusting the sound of the headphones depending on the level of ambient noise. In a noisy environment (for example, when traveling on the subway), the Adaptive ANC system enhances the work of “noise reduction”, in the absence of loud sounds from outside, it weakens the noise reduction.