Comparison Xiaomi Redmi Buds 4 Lite vs Apple AirPods 2 with Charging Case

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.

Range of wireless-capable headphones (see "Connection type").

When evaluating the range, it should be taken into account that this parameter is rather conditional and the actual range may differ slightly from the claimed one (usually in a smaller direction). So, when connecting via a radio channel, the range is indicated for perfect conditions — without interference and obstacles in the signal path. For Bluetooth models, the range also depends on the power of the Bluetooth module in the device to which the “ears” are connected. And the effectiveness of the IR channel may be reduced in hot weather or in bright sunlight. So when choosing according to this indicator, it's ok to take a certain margin.

On the other hand, there are two points worth noting. Firstly, in general, the specified range accurately describes the capabilities of the headphones, and it is quite possible to evaluate and compare different models with each other. Secondly, even in the most modest wireless “ears”, the communication range is about 8–10 m, 11–20 m is considered an average, and a fairly large number of devices can operate at distances of tens and even hundreds of metres. So paying attention to the range makes sense mainly in cases where you plan to move away from the signal source at a considerable distance — from 5 m or more — or listen to sound through walls.

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.

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 presence of a noise reduction system in its own headphone microphone.

In accordance with the name, such a system is designed to eliminate extraneous noise - primarily during conversations. It is usually based on an electronic filter that passes the sound of a human voice and cuts off background sounds such as city noise, the rumble of wind in the microphone grille, etc. As a result, even in noisy environments, thanks to the noise reduction of the microphone, speech is clear and intelligible; True, the system inevitably introduces distortions into the final sound, but they are not critical in this case.

— ENC. ENC (Environment Noise Cancellation) technology significantly reduces ambient noise with directional microphones. It is used both in gaming devices so that gamers can easily communicate in voice chat, and in TWS earphone models so that you can comfortably talk on the phone in a noisy environment.

— cVc. Microphone noise reduction cVc (Clear Voice Capture) is an advanced technology that is found mainly in expensive headphone models. cVc algorithms effectively suppress echo and noise from the environment. Sound processing using this technology is carried out at several levels at once - the algorithm determines the reference signal-to-noise level, automatically adjusts speech to the desired volume level, applies adaptive equalizers to process the entire voice, as well as specialized filters to remove...low-frequency bubbling, sibilants and hissing.

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.

A technology used in Bluetooth models (see "Connection") that allows the headphones to connect to multiple devices at the same time. Thanks to this, you can, for example, listen to music from a laptop, and when a call comes in on a mobile phone, switch the headphones to a conversation. This technology has its own characteristics for different manufacturers, and therefore, if the multipoint function is critical for you, you should separately clarify the details of its operation in the selected model.

Codecs and additional audio processing technologies supported by Bluetooth headphones (see “Connection”). Initially, sound transmission via Bluetooth involves fairly strong signal compression; This is not critical when transmitting speech, but can greatly spoil the impression when listening to music. To eliminate this shortcoming, various technologies are used, in particular aptX, aptX HD, aptX Low Latency, aptX Adaptive, AAC, LDAC and LHDC. Of course, to use any of the technologies, it must be supported not only by the “ears”, but also by the Bluetooth device with which they are used. Here are the main features of each option:

- aptX. A Bluetooth codec designed to significantly improve the quality of audio transmitted over Bluetooth. According to the creators, it allows you to achieve quality comparable to Audio CD (16-bits/44.1kHz). The benefits of aptX are most noticeable when listening to high-quality content (such as lossless formats), but even on regular MP3 it can provide a noticeable sound improvement.

- aptX HD. Development and improvement of the original aptX, allowing for sound purity comparable to Hi-Res audio (24-bits/48kHz). As in the original, the benefits of aptX HD are noticeable mainly on high-quality...audio, although this codec will not be out of place for MP3.

- aptX Low Latency. A specific version of aptX described above, designed not so much to improve sound quality, but to reduce delays in signal transmission. Such delays inevitably occur when working via Bluetooth; They are not critical for listening to music, but when watching videos or playing games, there may be a noticeable desynchronization between the image and sound. The aptX LL codec eliminates this phenomenon, reducing latency to 32 ms - such a difference is imperceptible to human perception (although for serious tasks like studio audio work it is still too high). aptX LL support is found mainly in gaming headphones.

- aptX Adaptive. Further development of aptX; actually combines the capabilities of aptX HD and aptX Low Latency, but is not limited to this. One of the main features of this standard is the so-called adaptive bitrate: the codec automatically adjusts the actual data transfer rate based on the characteristics of the broadcast content (music, game audio, voice communications, etc.) and the congestion of the frequencies used. This, in particular, helps reduce energy consumption and increase communication reliability; and special algorithms allow you to broadcast sound quality comparable to aptX HD (24 bits/48 kHz), using much less transmitted data. And the minimum data transfer latency (at the aptX LL level) makes this codec excellent for games and movies.

- A.A.C. A Bluetooth codec used primarily in portable Apple gadgets. In terms of capabilities, it is noticeably inferior to more advanced standards like aptX or LDAC: the sound quality when using AAC is comparable to an average MP3 file. However, for listening to the same MP3s, this is quite enough; the difference becomes noticeable only on more advanced formats. AAC hardware requirements are low, and its support in headphones is inexpensive.

— LDAC. Sony's proprietary Bluetooth codec. It surpasses even aptX HD in terms of bandwidth and potential sound quality, providing performance at the Hi-Res level of 24-bits/96kHz audio; there is even an opinion that this is the maximum quality that it makes sense to provide in wireless headphones - further improvement will simply be imperceptible to the human ear. On the other hand, supporting this standard is not cheap, and there are still quite a few gadgets with such support - these are, in particular, Sony smartphones, as well as mid- and high-end devices running Android 8.0 Oreo and later versions.

- LHDC. LHDC (Low latency High-Definition audio Codec) is a high-definition, low-latency codec developed by the Hi-Res Wireless Audio Alliance and Savitech. In the vast majority of cases, its support is implemented at the hardware level in Huawei and Xiaomi smartphones. The codec is also known as HWA (Hi-Res Wireless Audio). When using LHDC, signal transmission from the phone to the headphones is carried out with a bits rate of up to 900 kbps, a bits depth of up to 24 bits and a sampling frequency of up to 96 kHz. This ensures a stable and reliable communication with reduced latency. The codec is optimally suited for high-end wireless headphones and advanced digital audio formats.

The maximum battery life of headphones on one full charge of the battery or replaceable batteries in talk mode. A long working time will be relevant for those who expect to regularly conduct long telephone conversations. Note that in talk mode, autonomy may be lower than when listening to music, since the use of microphones and clear voice transmission algorithms puts an additional burden on the hardware of the headphones.