Comparison Sony NW-A55 vs Sony NW-A45

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).

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-bit/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-bit/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 f...or 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 bit/48 kHz), using several times less amount of 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-bit/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 simply be 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 bit rate of up to 900 kbps, a bit 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 track lists on Audio CDs, they recorded the sequence of tracks, their duration and title; nowadays, albums and compilations are often accompanied by a .cue file, recorded according to the principle “all tracks in a row in one audio file”. If the player supports CUE, then such an audio file can be listened to on it as a set of separate tracks, switching between them as desired — the player will take data from the .cue file about the start 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. Player support for audio formats that use lossless compression. Unlike lossy compression (in the same MP3), with this compression, the sound is not cut, all its details are preserved as much as possible. There are several lossless formats these days, the most popular being FLAC and APE (see "Supports audio formats"); the specific set of standards that the player is compatible with should be clarified separately. However, anyway, this function will be useful to those who appreciate the most complete and reliable sound. In this case, it is worth considering two nuances. Firstly, lossless files ha...ve a fairly large volume — one album can take several hundred megabytes. Secondly, in order to fully appreciate such sound, you will need high-quality headphones, and ideally a Hi-Fi level player (see "Type").

— Formats without compression (uncompressed). Support by the player for audio formats that do not provide 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 work in the digital-to-analogue converter (DAC) mode — when the device receives a digital audio signal from an external source (usually a computer USB port) and outputs analogue sound. 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: own 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 volume of the sound of individual frequency bands, thus changing the overall colour 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. Anyway, such a setting can be useful both for adjusting the sound to your own preferences, and for compensating for the shortcomings of the 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 — Classic, Rock, Pop, etc.

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

— Recording from FM-receiver. Ability to record radio programs received by the player's own tuner (see above). This feature 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 studio of a radio station, a live call, etc.

— Dictaphone. Ability to work the player in voice recorder mode — to record sound. Usually, 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 come in handy.

— Built-in speaker. 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 note that the capabilities of the built-in speaker are usually quite modest, as a result, the volume and sound quality are low.

— Digital camera. Own digital camera that allows you to use the player to shoot photos and videos. The quality of filming in most cases is not high, but there are exceptions — some models of players in this indicator are not inferior to middle-class smartphones. In addition, the cameras in this case are designed not so much for highly artistic shooting, but for “fixing the moment”. It is also worth noting that the location of the camera may be different. 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 calls. And the most advanced players (usually models with OS, see above) can have a pair of cameras — the main one and the front one.

Players controlled by sensors. Do not confuse such control with the touch screen (see "Display") — we are talking about the touch panel as a separate control.

Sensors give the player a neat and technological appearance, besides, they are purely subjectively perceived as a sign of an expensive and advanced device. Such controls are relatively expensive, but this price is almost invisible against the background of the total cost of the players. The main disadvantage of sensors is that it is almost impossible to work with them "blindly", by touch. Therefore, such control panels are usually complemented by more traditional elements — buttons, wheels, mechanical switches, etc.