Comparison Ruizu X02 8Gb vs Astro M5 8Gb

Players that are designed to be used while playing sports without experiencing any inconvenience. Distinctive features of "sports" models are miniature size, often — the presence of a clip for wearing on clothes (see below), as well as the simplest display, suitable only for displaying service data like the name of the current song (or even the complete absence of a display). Not all such devices are specially designed for lovers of an active lifestyle, but this does not prevent them from being successfully used while running, cycling, etc. And specialized options can have a case with water protection (up to the possibility of immersion in water) and even built-in fitness tools.

Type of memory cards supported by the player.

Memory cards perform two main functions. First of all, they increase the total amount of the player's memory; at the same time, such memory in terms of gigabytes is much cheaper than built-in drives. Secondly, a memory card allows you to exchange data with another device that has a card reader; for example, it can be used to copy music to the player from a laptop.

Modern players usually use SD or microSD cards of one version or another. SD cards have dimensions of 32x24 mm and are used in relatively large devices, miniature microSD (15x11 mm), respectively, in compact models. Versions can be:

— SD. This marking means that the device is capable of working with at least original SD cards (not related to later versions of SDHC or SDXC). Such cards can have up to 4 GB capacity, their capabilities are quite enough for most tasks related to content playback.

— SD/SDHC. Models compatible with both the original SD (see above) and the newer SDHC format. This format allows you to create removable media up to 32 GB.

— SD/SDHC/SDXC. Support for all major SD formats used today. About SD and SDHC, see above, and SDXC provides card capacity up to 2 TB and increased speed.

— microSD. Players guaranteed to work with original microSD cards. Technically, such cards are similar to the SD cards described above and differ from them only in size. At the s...ame time, it is worth noting that a device with such a marking may actually be compatible with more advanced media (like microSDHC or even microSDXC), just the manufacturer, for one reason or another, did not go into such details. You can clarify this point by evaluating the maximum supported card volume (see below)

— microSD/SDHC Players that support both the original microSD and the later microSDHC standard (see "SD/SDHC").

— microSD/SDHC/SDXC. Players with this marking are compatible with all modern versions of microSD cards — both the newest microSDXC (see "SD / SDHC / SDXC"), and previous standards (see above for them).

Players are produced that have two slots for memory cards at once — usually microSD. Basically, these are Hi-Fi devices (see "Type"), and this feature is provided for an additional increase in available memory volumes: Hi-Fi content has a significant amount and requires appropriate storage.

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).

The ratio between the level of the useful signal (clear sound) and extraneous noise, given by the player at the output. This parameter directly characterizes the quality of the built-in amplifier: it mainly takes into account the intrinsic noise of electronic circuits, and the higher the signal-to-noise ratio, the less these noises and the clearer the sound.

Note that in the case of players, this characteristic is often not particularly critical: the noise of the amplifier can be lost against the background of ambient sounds, especially in an urban environment, and for such situations even the most modest indicators, at the level of 70 – 80 dB, are enough. At the same time, for Hi-Fi models (see "Type") this moment is one of the most important; in the most advanced devices, the signal-to-noise ratio can exceed 120 dB.

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.
<...br> — 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.

Non-audio file formats that the player can handle.

— AVI. One of the most popular video file formats nowadays, it is used both in portable devices and in stationary video equipment. Technically, it is a container, that is, it can contain data processed by different codecs; playback requires that the device supports not only the AVI format, but also the corresponding codec.

— MP4. Video files using the MPEG-4 container. MP4 was once one of the most popular formats for portable players, and it is this format that is usually meant when people talk about "converted video" for a media player or smartphone.

— MPEG-4. Another name for the above MP4.

— MKV. A video container created as an open source alternative to the above described AVI and similar standards. Very handy when creating video files with multiple embedded video, audio and/or subtitle streams, which is why it is widely used and continues to evolve.

— MOV. Video file (container) format originally developed by Apple for QuickTime software players

— ASF. Microsoft's proprietary format, specifically designed to work with streaming content.

— SWF. A format in which animation clips are recorded based on flash technology.

— jpegs. One of the most popular modern image file formats, it is the standard for digital photography. Note that graphics support, including JPEG, can be pro...vided even in players with very miniature screens — to display album art.

— PNG. Popular graphic file format. In particular, it is widespread on the Internet due to the ability to achieve good quality with small file sizes.

— GIF. Another popular graphic file format. Notable for the ability to create animated pictures.

— BMP. One of the most common graphic formats. However, due to the rather large volumes of files, it is less common than the above standards.

— txt. Text-only files, no formatting (except paragraphs). Support for this format can be provided even in players with very small screens — to view lyrics.

This list is not exhaustive, other file formats may be supported in modern compact players.

- 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 take 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.

The player supports Bluetooth technology.

This technology is designed for direct wireless communication between different devices. There are different ways to implement it in players. The most common option is to broadcast sound to wireless headphones, acoustics or other similar equipment (aptX is highly desirable, see “Features/capabilities”). Other methods of application may also be envisaged - in particular, exchanging files with other devices and remote control (player or from the player). The specific set of additional functions should be clarified separately.

Bluetooth wireless protocols from the 4th revision and newer are relevant today:

• Bluetooth v 4.0. Revision 4.0 introduced a Bluetooth Low Energy (BLE) connection mode with low power 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, which has a positive effect on the stability of the connection.
• Bluetooth v4.1. Development and improvement of Bluetooth 4.0. In terms of players, the key innovation in this version was improved noise immunity when working near 4G (LTE) mobile communication devices (in earlier standards, Bluetooth and LTE signals could overlap, which led to failures).
• Bluetooth v4.2. Furt...her, after 4.1, development of the Bluetooth standard, which mainly presented a number of general improvements in the reliability and noise immunity of the connection.
• Bluetooth v5.0. 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). The key benefit of these innovations is to improve the overall reliability of communications, increase their range and reduce the number of breaks.
• Bluetooth v5.1. Update to revision v 5.0, in which, in addition to general improvements in the quality and reliability of communication, it became possible to determine the direction from which the Bluetooth signal is coming. Thanks to this, the location of connected devices is determined with centimeter accuracy, which has a positive effect on the quality of the wireless connection.
• 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 v 5.3 came into use 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 v 5.4 was introduced at the beginning of 2023. This edition has 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.

Characteristics of the display installed in the player.

— Color(color/monochrome). The display color is selected by the manufacturer taking into account the functionality of the player. So, for a device that supports video and graphic materials (see “Other formats”), a color display is mandatory, and if the player only works with audio, a monochrome (one-color) screen is quite sufficient for it, especially since such screens are cheaper and consume less energy.

- Size. The diagonal dimensions of the display is directly related to the type of device (see above). Thus, classic audio players do not require large screens, in most of them this figure does not exceed 1.5"; but for a media player, 1.5" is, in fact, the absolute minimum, usually the diagonal is 3" or more. Also large Hi-Fi players are equipped with screens, they also provide a similar feature for the convenience of working with special tools.In general, a large screen, on the one hand, is convenient to use, on the other hand, it affects the dimensions and price of the device.

— Display resolution. Display dimensions in pixels vertically and horizontally. With the same diagonal, a higher resolution provides a clearer and more detailed image, but increases the cost of the player. In addition, not every player needs high detail: if the screen is used only for service information like the title o...f a song, you can get by with small resolutions. Therefore, you should pay attention to this parameter only when it comes to a media player (see “Type”) on which you plan to often watch videos. In other cases, we can assume that the screen resolution is guaranteed to be sufficient for the tasks for which the device is intended.

— Sensor type. The type of matrix used in the screen.

• OLED. An OLED matrix in which each pixel is actually a separate LED. In portable players, most of these screens are monochrome; for color displays it is more convenient to use other technologies.
• TFT. General name for liquid crystal displays. In this case, the TFT designation is used mainly for relatively simple screens that do not use advanced technologies like the IPS described below and have rather limited characteristics. However, such screens can be made in color and have high resolution.
• AMOLED. A development of the OLED technology described above, designed to create high-quality color displays. AMOLED screens are characterized by high brightness, rich colors and good viewing angles. Among their disadvantages, we can note a slightly shorter service life than the same IPS, as well as a tendency to fade in areas where bright parts of the image are often displayed.
• IPS. One of the most popular color screen technologies used in modern portable technology. Provides good color rendering quality and wide viewing angles; The picture quality is somewhat inferior to AMOLED, but is cheaper and lasts longer.

- Touch screen. The touch screen is similar to tech used in modern smartphones. On-screen controls are often more convenient and versatile than using buttons and other hardware controls. For normal use, such a display must be quite large. We also note that a touch screen is mandatory for models with a full OS (see above).