Comparison Sony NW-A105 vs Sony NW-A55

- Audio. MP3 players in the original, most traditional sense are devices designed to play music and other audio. There are models without a display, but many of the audio players are equipped with screens and can work with auxiliary file formats - like TXT for displaying song lyrics or JPG for viewing album covers or even photos. But the player in them is designed to work only with sound and does not allow video playback.

- Media player. This type includes all players that can play video. The specific characteristics of such models may vary significantly - from portable gadgets with 1.5" - 2" displays and support for specific formats to large 4 - 5" devices capable of working with unconverted files. But in any case, if you need a pocket player with the ability not only listen to music, but also watch videos - it’s worth choosing from similar models.

— Hi-Fi player. A specific type of audio player (see above), created with the expectation of maximum quality of reproduced sound. Uses high-quality components and advanced signal processing circuits; Because of this, such devices are an order of magnitude more expensive than conventional audio players, but in terms of sound quality they are comparable to stationary Hi-Fi class systems. It is almost mandatory for such models to support at least one lossless format like FLAC or A...PE; also only in such devices is it possible to work in DAC mode (see “Functions/capabilities”). In addition, the design may provide specialized interfaces - for example, balanced or optical (see “Outputs”). Thanks to all this, devices of this type can be useful both to demanding audiophiles and to those who work professionally with sound.

The operating system under which the player is running.

An operating system is not just any shell programme; this name is applied to the most advanced platforms. The OS has extensive capabilities that go far beyond the traditional functionality of the players, in addition, these capabilities can be further expanded by installing additional applications for various purposes — from online music services and media libraries to games, social network clients, etc. Thus Thus, the presence of an OS usually means that the device is a media player (see "Type"); however, not every media player has a full OS. Hi-Fi players can also have such firmware, however, the OS in them is often heavily modified, and not all such devices allow the installation of third-party applications.

Specific options for the OS can be as follows:

— Android. Operating system developed by Google, widely used by manufacturers of portable electronics; practically ousted other systems from the market, the only alternative is iOS(see below). The original Android is tightly integrated with Google services and uses the Google Play app store; however, there are many branded shells and modifications on the market, including those with rather radical changes. And you can install programs not only from the application store, but also from any other sources — by downloading the installation file to the device. The system h...as an open source code, anyone can write software for this OS, thanks to which the set of applications for Android is extremely extensive, but many of them do not differ in quality.

— iOS. Apple's proprietary operating system is not used by other manufacturers. It is closed: you can install additional applications only from the App Store proprietary storage, and for music and video you need to use the iTunes service. In addition, to create software for iOS, you need to obtain a paid license, which limits the circle of developers. On the other hand, iOS is quite convenient in that the user doesn't have to dig through an extensive set of settings; and apps in the App Store go through fairly strict quality and security controls.

The maximum size of the memory card that can be used in the player. This parameter is directly related to the card type (see above): each type has its own volume limits. At the same time, the ability to work with capacious media is limited not only by the type of card, but also by the player's hardware. Therefore, many models have a lower capacity limit than the memory card suggests — for example, 128 GB in a model that supports the SDXC format (the theoretical maximum for which is 2 TB).

Note that the reverse situation also occurs — for example, when a device with a maximum capacity of 16 GB only supports microSD cards (theoretical maximum is 4 GB). This usually means that the player can work with newer formats (in our example, at least microSDHC), but for some reason this point is not mentioned in the official specifications (for example, the manufacturer could make a mistake in the documentation).

Sampling frequency of the digital-to-analogue converter installed in the player (see "DAC").

Sample rate and bit depth are two key characteristics of a digital audio signal; the higher they are, the better the sound quality, other things being equal. Without going into technical details, the meaning of this parameter can be described as follows: for normal sound reproduction, it is necessary that the sampling rate of the player's DAC is not lower than that of the file being played. Otherwise, playback will not be possible even if the audio format is natively supported by the player. (The exception is DSD, see "Supports audio formats" for more on that).

Note that most popular audio formats use a sampling rate of 44.1 kHz, and all modern portable players are guaranteed to support it. So this parameter is relevant mainly for Hi-Fi models (see "Type") that work with advanced digital sound formats.

The capacity of the digital-to-analogue converter installed in the player (see "DAC").

Bit depth, along with sampling rate, is one of the key characteristics of a digital audio signal; the higher it is, the better the sound quality, other things being equal. Without going into technical details, in this case, the meaning of this parameter can be described as follows: for normal sound reproduction, it is necessary that the bit depth of the player's DAC be no lower than the bit depth of the reproduced digital sound, otherwise playback will be impossible.

It is worth noting that the bit depth used in most popular music formats like MP3 is supported by all modern players. So this parameter is relevant mainly for Hi-Fi players (see "Type") that work with advanced digital sound standards.

The higher the power, the louder the sound you can get on the headphones, all other things being equal. In addition, higher power allows you to connect "ears" with higher impedance to the device (although there is no hard correlation here, and models with the same output power may have different headphone impedance limits). However, in the case of ordinary (non-Hi-Fi) players, this parameter is more of a reference than practically significant: usually, the power of the amplifier in such models is quite enough to “rock” most consumer-grade headphones. But for Hi-Fi devices (see "Type") models, output power is of key importance: it determines compatibility with high-resistance studio-class "ears". Detailed help on this issue can be found in special sources.

Audio file formats that the player is able to work with.

— MP3. The most famous of modern digital audio formats; supported by almost all compact players, the name MP3 has even become a household name for them. Provides so-called. lossy compression, where some of the audio frequencies are lost. However, during compression, the sound is processed in such a way that it "disappears" mainly frequencies, the loss of which is imperceptible to the human ear. As a result, the sound quality can be quite high, and you can clearly distinguish high-quality MP3 from lossless format only on Hi-Fi equipment.

— WAV. Another popular audio standard, originally developed for storing sound on a PC. It can technically be used to store audio in a variety of formats, but is most commonly used for uncompressed audio. Due to this, the sound quality can be quite high, and its processing does not require special computing power. The downside of this is the large volume of audio files — many times more than MP3s.

— WMA. An audio format, at one time specially created for the Windows operating system. By default, it uses lossy compression (although there is also a lossless version of the WMA codec). WMA is particularly suitable for low bitrates, under such conditions it provides better quality than MP3 and takes up less space. On the other hand, this format is much less popular in high-quality digital audio.

...— AAC. A format developed as a potential successor to MP3. Also provides lossy compression (see above), but allows you to achieve better quality with the same file size; this difference is especially noticeable at low bitrates. Actively promoted by Apple in iPod players; nevertheless, it is noticeably inferior to MP3 in terms of prevalence, although it is supported by a considerable number of players.

— OGG. A lossy compressed digital audio format is one potential alternative to MP3. One of the key features of OGG is that as audio is encoded, the bitrate is constantly changing; at the same time, on fragments where there is no sound, the bitrate drops to almost zero (unlike MP3, where the data stream is constant, including in sections of complete silence). This makes it possible to achieve small file sizes while maintaining sound quality. Also note that the OGG format is open and not limited by patents.

— FLAC. One of the formats that uses lossless audio compression. With this compression, all the details of the original sound are preserved, so lossless formats are especially appreciated by sophisticated music lovers and audiophiles. The reverse side of this quality is large volumes of files. Specifically, FLAC is perhaps the most common of today's lossless formats. This is largely due to the fact that this standard is not particularly demanding on the processing power of the player. Thanks to this, its support can be implemented even in relatively simple and inexpensive players (unlike another popular format — APE, see below). On the other hand, FLAC files are larger than APE files.

— A.P.E. One of the popular lossless audio compression formats. Compared to another common standard — FLAC (see above) — APE allows you to achieve smaller file sizes with the same quality. On the other hand, to play such files, electronics with a fairly high processing power are required, so APE compatibility is relatively rare in compact players.

— DSD. A specific digital audio format using the so-called. sigma-delta modulation (as opposed to pulse code used in most other formats). Such modulation provides a very high sampling rate — 2822.4 kHz; however, it cannot be compared with the usual sampling rate (see above): in this case we are talking about a specific signal format. Its properties are such that DSD support can be provided even if the player's DAC formally has a much lower sampling rate. In general, this format is considered professional, its support is found mainly in Hi-Fi models (see "Type").

— DXD. Professional audio format originally created for editing DSD files (see above) — For technical reasons, original DSD is not well suited for editing. DXD uses a bit depth of 24 bits (8 bits higher than Audio CD format) and a sampling rate of 352.8 kHz (8 times higher than Audio CD). Like the original DSD, it is found mainly in Hi-Fi players.

— AIFF. Audio format developed by Apple for Macs and Macbooks; a kind of "apple" analogue of the WAV described above, also in most cases used for uncompressed audio.

— Audible. Proprietary file format used by the online audiobook store of the same name. One of the features of this format is that file playback is available only if you enter a login and password for the Audible online store; thus, supporting this standard usually means having a client programme to access the store.

This list is not exhaustive, modern players (especially the top category) may support other types of audio files.

Codecs and additional audio processing technologies supported by the Bluetooth-connected player. Initially, sound transmission via Bluetooth involves quite strong signal compression, which can greatly spoil the experience when listening to music. To eliminate this drawback, various technologies are used, in particular aptX, aptX HD, aptX Low Latency, aptX Adaptive, AAC, LDAC, LHDC. Of course, to use any of the technologies, it must be supported not only by the player, but also by the Bluetooth device with which it is 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 video, there may be a noticeable desynchronization between the image and sound. The aptX LL codec eliminates this phenomenon, reducing latency to 32 ms - a difference that is imperceptible to human perception.

- 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 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.

- 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.

— 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 makes sense to provide for in wireless transmission - further improvement will be simply imperceptible to the human ear.

- 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. The codec is also known as HWA (Hi-Res Wireless Audio). When using LHDC, signal transmission 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 connection with reduced latency. The codec is optimally suited for high-end wireless headphones and advanced digital audio formats.

- CUE support. The player's ability to recognize and use .cue files. Initially, such files were used as lists of tracks on an Audio CD; the sequence of tracks, their duration and name were recorded in them; Nowadays, .cue files often accompany albums and collections recorded on the principle of “all tracks in a row in one audio file.” If the player supports CUE, then you can listen to such an audio file on it as a set of separate tracks, switching between them at will - the player will take data from the .cue file about the starting point of each track and automatically skip playback. In other words, the listening format will be the same as when playing music in the “one file per track” format.

— Lossless formats. The player supports audio formats that use lossless compression. Unlike lossy compression (including MP3), with this compression the sound is not cut down, all its details are preserved as much as possible. Nowadays, there are several lossless formats, the most popular are FLAC and APE (see “Supports audio formats”); The specific set of standards with which the player is compatible should be clarified separately. However, in any case, this function will be useful to those who value the most complete and reliable sound. It is worth considering two nuances. Firstly, lossless files are quite large - one album can ta...ke up several hundred megabytes. Secondly, in order to fully appreciate such sound, you will need high-quality headphones, and ideally a Hi-Fi player (see “Type”).

— Formats without compression (uncompressed). The player supports audio formats that do not require data compression. Most of these standards are professional; they provide very high quality and reliability of sound, but they also take up a lot of space. Examples of uncompressed formats include DSD and DXD (see “Supports Audio”).

— Work in DAC mode. The ability of the player to operate in digital-to-analog converter (DAC) mode - when the device receives a digital audio signal from an external source (usually a computer USB port) and outputs analog audio. This function is found mainly in Hi-Fi models (see “Type”). It will be useful primarily when outputting sound from PCs, laptops or portable gadgets: the native sound cards in such models are often quite “weak”, and when using an external DAC you can achieve much better sound quality.

— Equalizer. This function allows you to adjust the sound volume of individual frequency bands, thus changing the overall color of the sound. Equalizers in modern players can have a different number of bands - from 2 (low and high frequencies) in the simplest models to 8 - 10 in advanced ones. In any case, such a setting can be useful both for adjusting the sound to your own preferences, and for compensating for the shortcomings of connected headphones or speakers - if they “fail” certain frequency bands. In addition, many players have a set of equalizer presets (presets), usually designed for different styles of music - “Classical”, “Rock”, “Pop”, etc.

- FM receiver. Built-in tuner for receiving radio broadcasts in the FM range. It is this range that the vast majority of modern music radio stations use, since it allows broadcasting sound in stereo format. However, some player models also support other standards - for example, AM, in which talk stations are widely represented. To listen to the radio, you usually need to connect headphones - their wire acts as an antenna.

— Recording from an FM receiver. Possibility of recording radio programs received by the player’s own tuner (see above). This function is useful if you want to “save for history” some event from the broadcast - an interesting talk show, a live performance of your favorite band in the radio station’s studio, a live call, etc.

- Dictaphone. The player can operate in voice recorder mode to record sound. Typically, the built-in microphone is used. The general functionality of such a recording is noticeably more modest than in specialized voice recorders, but for simple tasks it may well be useful.

— Built-in speaker. Its own built-in speaker allows you to listen to music without connecting headphones or speakers. In some situations - for example, when watching a movie together from the player screen - this function can be very useful. However, it is worth considering that the capabilities of the built-in speaker are usually quite modest; as a result, the volume and sound quality are low.

- Digital camera. Your own digital camera that allows you to use the player to take photos and videos. The quality of filming in most cases is not high, but there are exceptions - some player models are not inferior to middle-class smartphones in this indicator. In addition, the cameras in this case are intended not so much for highly artistic filming, but for “capturing the moment.” It is also worth noting that the location of the camera may vary. Most often it is installed on the back side, but there are also players with front cameras that allow you to take selfies and use video calling. And the most advanced players (usually models with OS, see above) may have a pair of cameras - main and front.