Comparison OPPO Enco X2 vs OnePlus Buds Pro 2

The specific connection interface provided in the headphones. At the same time, some models may provide several options at once - these are either combined devices (see "Type of connection"), or wired headphones equipped with additional adapters or replaceable cables, or wireless devices connected via a radio channel or infrared port (in the latter case the characteristics additionally specify the method of connecting the complete adapter).

- micro-Jack (2.5 mm). A wired connector similar to the popular 3.5mm mini-Jack (see below), but smaller. Equipment with such a connection is rare - mostly these are miniature devices, where there is simply no room for a 3.5 mm jack. Accordingly, this interface has not received distribution among headphones either: it is almost never found in its pure form, models with such a plug are usually supplemented with an adapter or cable for mini-Jack.

- mini-Jack(3.5 mm). Perhaps the most popular modern type of audio connector; if a device has a headphone output, it is most likely a 3.5 mm jack. Accordingly, most headphones with a wired connection use this type of connector. It is worth noting that headphones with a microphone designed for such a connection are equipped with a special plug for a combined headphone + microphone audio jack (such connectors are popular in portable gadgets and laptops). But with a socket designed only for “ears” without a microphone, such a plug may not work cor...rectly. An alternative would be headphones equipped with two separate mini-jack plugs; see below for more details on this option.

- mini-Jack (2 x 3.5 mm). Models with two 3.5 mm mini-jack plugs. This option is guaranteed to mean that we are not talking about classic headphones, but about a headset with a microphone: one plug is used for headphones, the second for a microphone. Such models are convenient when used with equipment that has separate 3.5 mm jacks for “ears” and a microphone - for example, for a PC.

- Pentaconn (4.4 mm). It is a 5-pin balanced output. Pentaconn uses a larger than the mini-Jack plug, its size is 4.4 mm, it is stronger and more reliable than the 3.5 mm connection. The Pentaconn's balanced connection makes it possible to handle higher power audio signals. Thanks to this connection, it is possible to transmit a signal over a fairly long distance. Accordingly, such a connector is relevant for headphones of the highest category.

- Jack (6.35 mm). The largest type of Jack type audio connector found in modern technology. Outputs of this type are found mainly in stationary audio equipment - they are too bulky for portable devices, it is easier to use a 3.5 mm mini-jack there. At the same time, a 6.35 mm jack is considered to be a more suitable interface for professional and audiophile-class equipment: it provides a more reliable connection, greater contact density and, accordingly, less likelihood of interference. Therefore, although relatively few headphones are equipped with their own Jack type connector (mostly premium solutions), many models with a 3.5 mm mini-Jack plug are equipped with a 6.35 mm adapter.

— XLR. A characteristic round connector with a lock-lock and 3 contacts (there are other options in quantity). As a rule, it is used to transmit an analog signal through a balanced connection. This connection provides high resistance to interference, typical for professional applications; at the same time, the plug itself has rather large dimensions. In view of all this, the presence of XLR is relevant mainly for headphones designed for use with advanced stationary equipment.

— Bluetooth. The most popular wireless connection option in today's headphones. This is due to the fact that built-in Bluetooth modules are available in almost any modern smartphone, tablet or laptop, and appropriate adapters can be produced for devices without this module (for example, a PC). True, the sound quality with a traditional Bluetooth connection is relatively low, but special technologies such as aptX and aptxHD are increasingly being used to remedy the situation (see "Codec Support").
It is also worth noting that Bluetooth modules can correspond to different versions (the latest for 2022 is Bluetooth 5.0, Bluetooth 5.1, Bluetooth 5.2 and Bluetooth 5.3) this moment does not affect the sound quality, however, it determines a number of additional nuances - the range and reliability of communication, the ability to work through walls and other obstacles, resistance to interference, etc. In modern "ears" you can find the following versions of Bluetooth:

• Bluetooth v4.0. An update in which the capabilities of version 3.0 (classic + high-speed Bluetooth) were supplemented with a third format - Bluetooth LE (low energy). This communication standard is intended mainly for the transmission of small amounts of information - in particular, service data packets to maintain a connection. At the same time, the creators managed to combine economical energy consumption and a long communication range - it can reach 100 m. This has a positive effect on the stability of the connection.
• Bluetooth v 4.1. Development and improvement of Bluetooth 4.0. Speaking specifically about headphones, the key innovation for them in this version was improved noise immunity when working near devices with 4G (LTE) mobile communication devices (in earlier standards, Bluetooth and LTE signals could overlap, which led to failures). So for use with a 4G smartphone, headphones with Bluetooth support of at least v 4.1 are definitely recommended.
• Bluetooth v4.2. Further, after 4.1, the development of the Bluetooth standard, which mainly introduced a number of general improvements in reliability and noise immunity.
• Bluetooth v5.0. Massive Bluetooth update released in 2016. One of the most notable innovations was the introduction of two additional Bluetooth LE operating modes: high speed mode (due to reduced range) and extended range mode (due to reduced speed). In the case of headphones, the main significance of these innovations is to improve the overall reliability of the connection, increase its range and reduce the number of gaps.
• Bluetooth v 5.1. Update version v 5.0, which, in addition to general improvements in the quality and reliability of communication, has such an interesting feature as determining the direction from which the Bluetooth signal is coming. Thanks to this, a smartphone or other gadget that supports this standard is able to determine the location of connected devices with an accuracy of up to a centimeter; this can be useful, for example, to search for lost sight, but still working headphones.
• Bluetooth v5.2. The next, after 5.1, is the Bluetooth 5th generation update. The main innovations in this version are a number of security improvements, additional power optimization in LE mode, and a new audio signal format for synchronized parallel playback on multiple devices.
• Bluetooth v5.3 was introduced at the dawn of 2022. Among the innovations, it accelerated the process of negotiating the communication channel between the controller and the device, implemented the function of quickly switching between the state of operation in a small duty cycle and high-speed mode, improved the throughput and stability of the connection by reducing the susceptibility to interference. In case of unexpected interference in the Low Energy mode of operation, the procedure for selecting a communication channel for switching is now accelerated.

- Radio channel. A wireless radio connection that does not use Bluetooth technology (see above). Such headphones are usually equipped with an adapter that connects to the signal source by wire - for example, via USB or mini-Jack 3.5. This connection method is more versatile than Bluetooth, it can be used even with devices that do not have wireless modules. In addition, the radio channel provides a long range (often up to several tens of meters), and the sound quality is quite high even without the use of special technologies. The disadvantage of this option is the actual presence of an adapter, which is not always appropriate: for example, it is easier to use Bluetooth headphones with a tablet or smartphone.

- IR channel. Another method of wireless connection, a feature of which is that it does not use radio waves, but infrared radiation. Theoretically, the advantage of such a connection is resistance to electromagnetic interference, the disadvantage is that it only works in the line of sight. In practice, the situation is such that in most cases it is easier to use Bluetooth or a radio channel for a wireless connection. So this option is found only in specialized devices for equipment equipped with its own IR outputs - in particular, among headphones for car monitors.

— USB A. Wired connection to a standard (full dimensions) USB connector. This option is found exclusively among headphones designed for computers / laptops or gaming consoles. One of its advantages is that sound via USB is transmitted digitally and is processed not by the computer's audio card, but by the built-in headphone converter; such a converter often provides better sound quality than the said audio card. In addition, multi-channel audio can be transmitted via a USB connection - this point will be especially appreciated by gamers. Another advantage is that when using USB-headphones, specialized audio outputs remain free, and you can connect other equipment to them - for example, computer speakers or a vibrocap.

— USB-C. A relatively new type of USB connector, used in both desktop computers and portable devices - as the heir to microUSB. It does not differ much in dimensions, but it has a more advanced design - in particular, it is made double-sided, which makes it easier to connect. Most often complemented by other connection options (they can be both wired and wireless).

— Lightning. A universal connector used in Apple portable equipment - iPhone smartphones and iPad tablets - since 2012. Not used by other manufacturers. Accordingly, models with such an interface are designed specifically for "apple" technology (primarily iPhone and iPod touch players). This type of connection is especially relevant given the fact that in the latest iPhones, the manufacturer has completely abandoned a separate audio output, and the only way to connect headphones is the Lightning port.

- Corporate outlet. A connection connector that is not related to generally accepted standards and is used to a limited extent in the equipment of one or more manufacturers. Such connectors are found mainly among headphones for mobile phones. However, in connection with the general standardization, this option has practically disappeared from the scene. Theoretically, the proprietary connector is also the Lightning described above, but it is separated into a separate category due to the popularity of Apple technology.

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.

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 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.

A sensor in the design of in-ear headphones that allows you to naturally distinguish your own voice from the background sound. The sensor picks up the vibration of the user's voice and does not respond to external sounds, providing a clear voice transmission during voice calls.

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.

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.