Comparison OPPO Enco Air3 Pro vs OPPO Enco Air2 PRO

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 “Connection type”) or wired headphones equipped with additional adapters.

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

— mini-Jack(3.5 mm). Perhaps the most popular modern type of audio connector; If a device claims to have a headphone output, most likely it is 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 connector (similar connectors are popular in portable gadgets and laptops). But with a jack intended only for “ears” without a microphone, such a plug may not work correctly. An alternative could 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 plug compared to the mini-Jack; its size is 4.4 mm, which is stronger and more reliable than the 3.5 mm connection. Pentaconn's balanced connection makes it possible to work with high-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 - for portable devices they are too bulky, where it is easier to use a 3.5 mm mini-jack. At the same time, the 6.35 mm connector is considered a more suitable interface for professional and audiophile-grade equipment: it provides a more reliable connection, greater contact density and, accordingly, less likelihood of interference. Therefore, although relatively few headphones (mostly premium solutions) are equipped with their own Jack type connector, many models with a 3.5 mm mini-Jack plug are equipped with an adapter to 6.35 mm.

- XLR. A characteristic round connector with a locking lock and 3 contacts (there are other options for quantity). Typically, it is used to transmit an analog signal over a balanced connection. This connection provides high immunity to interference, typical for professional use; at the same time, the connector itself has quite 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 modern 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 to correct the situation, special technologies like aptX and aptxHD are increasingly being used (see “Codec support”).
It is also worth noting that Bluetooth modules can correspond to different versions (the latest for 2022 are Bluetooth 5.0, Bluetooth 5.1, Bluetooth 5.2, Bluetooth 5.3, Bluetooth 5.4). This point does not affect the sound quality, but it determines a number of additional nuances - communication range and reliability , 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 v 4.0. An update in which the capabilities of version 3.0 (classic + high-speed Bluetooth) were supplemented with a third format - Bluetooth LE (low energy consumption). This communication standard is intended mainly for transmitting 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 v4.1. Development and improvement of Bluetooth 4.0. If we talk specifically about headphones, the key innovation for them in this version is improved noise immunity when working near 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, development of the Bluetooth standard, which mainly introduced a number of general improvements in reliability and noise immunity.
• Bluetooth v 5.0. Major Bluetooth update released in 2016. One of the most notable innovations was the introduction of two additional operating modes of Bluetooth LE: an increased speed mode (by reducing the range) and an extended range mode (by reducing the 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 dropouts.
• Bluetooth v5.1. Update version v 5.0, in which, in addition to general improvements in the quality and reliability of communication, an interesting feature has appeared, such 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 a centimeter; This can be useful, for example, for finding headphones that have disappeared from sight but are still working.
• Bluetooth v5.2. The next update, after 5.1, is Bluetooth 5th generation. The main innovations in this version are a number of security improvements, additional optimization of power consumption in LE mode and a new audio signal format for synchronizing parallel playback on multiple devices.
• Bluetooth v5.3 was introduced at the dawn of 2022. Among the innovations in it, they accelerated the process of negotiating a communication channel between the controller and the device, implemented the function of quickly switching between the operating state in a low duty cycle and a high-speed mode, and improved the throughput and stability of the connection by reducing susceptibility to interference. When unexpected interference occurs in Low Energy mode, the procedure for selecting a communication channel to switch from now on has been accelerated.
• Bluetooth v5.4. introduced at the beginning of 2023, increased the range and speed of data exchange. Also in Bluetooth v 5.4, the energy-saving BLE mode has been improved. This version of the protocol uses new security features to protect data from unauthorized access, has increased connection reliability by selecting the best channel for communication, and prevents connection losses due to interference.

— Radio channel. Wireless connection via radio channel that does not use Bluetooth technology (see above). Such headphones are usually equipped with an adapter that connects to the signal source wired - for example, via USB or mini-Jack 3.5. This connection method is more universal 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 presence of an adapter, which is not always appropriate: for example, it is more convenient to use Bluetooth headphones with a tablet or smartphone.

- IR channel. Another method of wireless connection, the peculiarity of which is that it does not use radio waves, but infrared radiation. Theoretically, the advantage of such a connection is its resistance to electromagnetic interference, the disadvantage is that it only works in 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 exclusively in specialized devices for equipment equipped with their 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 mentioned 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 vibration pad.

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

- Lightning. A universal connector used in Apple portable devices - 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 option for connecting headphones is the Lightning port.

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

Headphone support for Hi-Res Audio. The corresponding format is designed to provide a sound close to that recorded in the studio. Hi-Res Audio refers to a digital signal with parameters from 96 kHz / 24 bits, and for analog technology, the requirement for an extended frequency response is set from 40 kHz. Audio tracks in this format sound as close as possible to the original ideas of the authors of the compositions. The Hi-Res license marks premium headphones for avid audiophiles.

A special game mode in wireless headphones that minimizes the delay in transmitting an audio track from a connected source. Low Input Lag) provides the ability to quickly respond to what is happening in virtual battles and prevents the picture from being out of sync with the sound. At the same time, when you activate the game mode, wireless headphones will be discharged faster.

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 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.

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 diameter of the speaker installed in the headphones; models with multiple drivers (see "Number of drivers"), usually, the size of the largest speaker is taken into account, other dimensions can be specified in the notes.

In general, this parameter is relevant primarily for over-ear headphones (see "Design"). In them, emitters can have different sizes; the larger it is, the more saturated the sound is and the better the speaker reproduces the bass, however, large emitters have a corresponding effect on the dimensions, weight and price of the headphones. But in-ear "ears" and earbuds, by definition, have very small speakers, and rich bass in them is achieved due to other design features.

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.

Bass boost function for powerful and rich bass. Often implemented as a single button, with which you can actually "turn the bass on and off." Bass Boost is more convenient than adjusting low frequencies with an equalizer; in addition, various special technologies can be used to enhance the bass.