Range
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.
Sound
The audio format supported by the headphones.
— Stereo. Two-channel sound that allows you to create a surround sound effect to a certain extent (due to the difference in the right and left channels). The design of the headphones (two speakers, one for each ear) was originally “sharpened” specifically for stereo, so the vast majority of models support this particular sound format.
— Mono. Single-channel sound that does not create a surround effect. This marking means that this model is equipped with
one earpiece ; At the same time, there are two types of such devices on the market. The first is headphones that initially have only one cup and are designed for situations where the second ear needs to be left open (for example, to work on the phone in the office). The second is true wireless devices (see Cable Type), sold singly to replace a lost earphone from the original pair.
— 5.1. Originally, 5.1 was designed to create surround sound that can come from any direction ("surround"). It assumes the presence of 5 main channels (centre, front left / right, rear left / right) and one bass. In headphones, the effect of this sound is achieved through the use of several speakers in each cup. Such models are very convenient when watching movies with multi-channel sound, as well as in games — they provide a powerful immersive effect. On the other hand, such headphones are not cheap, and besides, they require a specifi
...c connection method (for example, via USB).
— 5.1 (virtual). Models with support for 5.1 surround sound (see above), in which the surround effect is achieved not due to the number of speakers, but due to special sound processing technologies. This somewhat reduces the accuracy compared to the "non-virtual" multi-channel, but it can significantly reduce the cost and weight of the headphones. However, there can also be several speakers in such models — for example, for separation by frequency.
— 7.1. The 7.1 format is the multi-channel 5.1 described above, supplemented by two more main channels. The localization of these channels depends on the specific variety of 7.1, but anyway they enhance the effect of volume. On the other hand, full support for this format significantly affects the dimensions, weight and price of the headphones, and content with 7.1 sound is produced much less than 5.1.
— 7.1 (virtual). A “virtual” version of the 7.1 format described above, in which the effect of surround sound is provided primarily through special signal processing, and not due to the presence of separate emitters for each channel. Similar to virtual 5.1, this format of operation somewhat reduces the reliability of the sound, but this difference is often imperceptible, and the headphones themselves turn out to be simpler and more inexpensive. Therefore, most modern 7.1 models support the virtual format of this sound.
— 9.1 (virtual). Further development of the idea of multi-channel sound: 5 channels, as in 5.1 (see above), supplemented by 4 more channels for more accurate localization of audible sound. As in other virtual formats, volume in this case is provided by special processing algorithms.
It is worth remembering that the actual sound will depend not only on the headphones, but also on the signal source: for example, a mono recording even in 9.1 “ears” will not become voluminous.
— 3D sound. Surround sound with the localization of sound sources in three-dimensional space allows you to deeply plunge into the atmosphere of films or immerse yourself in a virtual game world. The mechanics of spatial 3D-sound provides localization of sound sources around the listener and in the vertical scan plane. Algorithms for implementing 3D sound in headphones differ in terms of software and hardware support, but all of them are aimed at achieving the effect of realism of what is happening. Surround sound has long been the standard for movies, and in recent years, 3D sound has become increasingly common in games and music tracks.Hi-Res Audio
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.
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.
Impedance
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.
Sensitivity
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.Microphone noise canceling
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.Codec support
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 several times less amount of transmitted data. And the minimum data transfer latency (at the aptX LL level) makes this codec excellent for games and movies.
- aptX Lossless. The next stage in the development of aptX technology, which involves transmitting CD-quality sound over a wireless Bluetooth network without loss or compression. Audio broadcasting with sampling parameters of 16 bits / 44.1 kHz is carried out with a bitrate of about 1.4 Mbit/s - this is about three times faster than it was in the aptX Adaptive edition (see above). Support for aptX Lossless began to be introduced at the end of 2021 as part of the Snapdragon Sound initiative from Qualcomm.
- 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.Voice assistant
Headphones with voice assistant support the user interaction with the device to a new level. The call of the
assistant. is carried out by pressing one of the control buttons on the headphones or by a specific voice command (for example, «Ok, Google» for the Google Assistant virtual apprentice). The assistant pauses playback, instantly changes the volume of the music, can notify the user of new alerts, helps to answer messages without the help of hands, and commands are given to the paired smartphone via voice control from the headphones.