Comparison Xiaomi Mi In-Ear Headphones Pro HD vs 1More Piston v2

The length of the cable supplied with the headphones with the appropriate connectivity.

The optimal cable length depends on the planned format of the "ears". So, for pocket gadgets, 1 metre or less is often enough, for a computer it is already desirable to have a wire for 1 – 2 m, and preferably 2 – 3 m. And models with a longer cable length — 3 – 5 m or even more — are mainly designed for specific tasks, such as connecting to a TV or using in recording studios.

Recall that in some models the cable is removable (see below) and can be replaced if necessary with a longer or shorter one. Also note that there are extension cables that allow you to increase the length of the main wire; such a cable may even be included in the delivery, this point (and the length of the additional cable) is usually specified in the notes.

Impedance refers to the headphone's nominal resistance to AC current, such as an audio signal.

Other things being equal, a higher impedance reduces distortion, but requires a more powerful amplifier — otherwise the headphones simply will not be able to produce sufficient volume. Thus, the choice of resistance depends primarily on which signal source you plan to connect the "ears". So, for a portable gadget (smartphone, pocket player), an indicator of 16 ohms or less is considered optimal, 17 – 32 ohms is not bad. Higher values — 33 – 64 ohms and 65 – 96 ohms — will require quite powerful amplifiers, like those used in computers and televisions. And models with a resistance of 96 – 250 ohms and above are designed mainly for Hi-End audio equipment and professional use; for such cases, detailed recommendations for selection can be found in special sources.

The range of audio 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, some nuances should be taken into account here. First of all, we recall that the range of perception of the human ear is on average from 16 Hz to 22 kHz, and for the full picture it is enough that the headphones cover this range. However, modern models can noticeably go beyond these limits: 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 extensive ranges in themselves do not provide practical advantages, but they usually indicate a high class of headphones, and sometimes they are only given for promotional purposes.

The second important point is that an extensive frequency range in itself is not a guarantee of good sound: the sound quality also depends on a number of parameters, primarily the frequency response of the headphones.

Rated headphone sensitivity. Technically, this is the volume at which they sound when a certain standard signal from the amplifier is connected to them. Thus, sensitivity is one of the parameters that determine the overall volume of the headphones: the higher it is, the louder the sound will be with the same input signal level and other things being equal. However, we must not forget that the volume level also depends on the resistance (impedance, see above); moreover, it is worth choosing “ears” for a specific device first by impedance, and only then by sensitivity. In this case, one parameter can be compensated for by another: for example, a model with high resistance and high sensitivity can work even on a relatively weak amplifier.

As for specific figures, headphones with indicators of 100 dB or less are designed mainly for use in a quiet environment (in some similar models, the sensitivity does not exceed 90 dB). For use on the street, in transport and other similar conditions, it is desirable to have more sensitive headphones — about 101 – 105 dB, or even 110 dB. And in some models, this figure can reach 116 – 120 dB. and even more.

It is also worth noting that this parameter is relevant only for a wired connection according to the analogue standard — for example, via a 3.5 mm mini-...jack. When using digital interfaces like USB and wireless channels like Bluetooth, the sound is processed in the built-in headphone converter, and if you plan to mainly use this kind of application, you can not pay much attention to sensitivity.

The type of sound emitters installed in the headphones. The type determines the principle of operation of emitters and some features of their design.

— 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.

The number of emitters installed in each individual earphone. Specified only for models with more than one emitter.

The meaning of this feature depends on the type of emitters (see above). So, in hybrid models, by definition, there are several — the frequency range is distributed between them, which has a positive effect on the frequency response. For the same purpose, several reinforcing radiators can be used. And with the traditional dynamic principle of operation, due to several emitters, the effect of surround sound can also be provided (see "Sound").

Anyway, "ears" with numerous emitters, other things being equal, will be more advanced, but also more expensive.

The total weight of the headphones; for true wireless models (see "Cable Type"), the weight of each individual earbud is listed.

This parameter is directly related to the design (see above) and some features of the functionality. Thus, the mentioned true wireless devices are very light, their weight does not exceed 25 g. More traditional in-ears and in-ears can be noticeably heavier, up to 50g for in-ears and up to 100g for most in-ears. Overhead models, for the most part, are quite massive: among them there are many models weighing 200 – 250 g, 250 – 300 g and even more than 300 g. It should be noted that a significant weight for false ears is often not a disadvantage, but an advantage: it allows them to stay on the head more securely, creates an impression of solidity and reliability, and most often does not create significant inconvenience.