Comparison HIDIZS AP80 Pro vs HIDIZS AP80

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).

Model of the digital-to-analogue converter installed in the device.

The DAC is one of the key components of any player: it converts the digital data recorded in the audio file into an analogue audio signal, which is fed through an amplifier to the headphones. The quality of the DAC directly affects how accurately the output sound will match the original signal, as well as whether the player can work with advanced digital signal formats: many of them require high computing power, which is not available in every DAC.

Note that the DAC model is indicated only if it is a high-end converter with above-average sound quality. On the modern market, in particular, DACs from such manufacturers are represented: AKM, Cirrus Logic, ESS Saber, Texas Instruments, Wolfson. And players with such equipment usually refer to Hi-Fi devices(see "Type").

It is also worth mentioning that the number of DACs can be different. The simplest option is one module for both sound channels, however, there are players equipped with two converters at once — one per channel. This "division of labor" affects the cost, but reduces the load on each individual DAC, which has a positive effect on the quality and reliability of the sound.

The nominal impedance (impedance) of the headphones that the player can handle normally.

Most consumer-grade headphones are 16 or 32 ohm impedance, which is supported by almost all modern players. Therefore, you should pay attention to this parameter only if you plan to use a device with high-quality "ears" of a studio or audiophile class. A characteristic feature of these headphones is high resistance, already in the hundreds of ohms, and not every player is suitable for them.

Also, it will not hurt to clarify the permissible headphone impedance if you are buying a Hi-Fi class device (see "Type"). Some of these models have a fairly high minimum resistance and are not compatible with standard 16 ohm (and sometimes 32 ohm) "ears".

The coefficient of harmonic distortion produced by the player.

This parameter directly characterizes the amount of distortion introduced by the device into the original sound: the lower the coefficient, the clearer the sound, the less such distortion. It is impossible to completely eliminate them, but they can be reduced to a level that is practically not perceived by a person. So, it is believed that distortions at the level of 0.5% are already invisible even to an experienced listener. At the same time, in modern audio technology, there are also much lower values \u200b\u200b- up to ten thousandths of a percent. In the case of players, such indicators play mainly an advertising role — they are a sign of a high level of the device.

Note that the coefficient of harmonic distortion is indicated mainly for Hi-Fi players (see "Type"), for which the maximum purity of sound is critical; in conventional models, it is of secondary importance.

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. Further..., 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.

— micro-Jack (2.5 mm). The micro-Jack connector belongs to the category of TRS connections (Tip, Ring, Sleeve). The 2.5mm plug is the smallest diameter TRS plug. Micro-Jack connection (2.5 mm) is typical for mobile devices and compact portable audio equipment. The connector is backwards compatible with mini-Jack (3.5 mm) and Jack (6.35 mm), but for this you must use the appropriate adapters. Of course, when using adapters, note that the presence of an additional connection reduces the overall quality of the audio signal. To prevent degradation in quality, some MP3 players are equipped with a micro-Jack output in parallel with the mini-Jack or Jack.

— mini-Jack (3.5 mm). The mini-Jack (3.5 mm) connection is the most common type of TRS (Tip, Ring, Sleeve) interface. The mini-Jack output is found on the vast majority of consumer-grade MP3 players. The mini-Jack connector has a 3.5 mm plug — this is the middle (intermediate) type of TRS connections. The mini-Jack output is capable of transmitting an audio signal of sufficiently high quality. The mini-Jack connection is ready to satisfy the needs of both beginners and advanced music lovers.

— Pentaconn (4.4 mm). Pentaconn connection — 5-pin balanced output. Thanks to this connection, you can connect powerful amplifiers or DACs to your MP3 player. Additionally, the connector is also suitabl...e for connecting good high-impedance headphones. Pentaconn uses a larger than the mini-Jack plug, its diameter 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.

— Coaxial. The coaxial connection (S/PDIF) enables the transmission of an enhanced audio signal. In the coaxial signal algorithm, there is no digital to analogue conversion stage, which has a positive effect on the quality characteristics of the sound. RCA or TOSLINK connectors can be used for coaxial connection. Coaxial output is found mainly in Hi-End MP3 players. This is an expensive technique that requires the use of fairly expensive accessories. But in return, these players provide high-quality sound, designed for professional musicians and advanced music lovers.

— Optical. The optical connection is represented by a TOSLINK connector and a fibre optic cable. The essence of the optical connection is that the audio signal is converted from electrical to optical. At the other end of the cable, the optics are transformed back into digital sound. Being in optical form, the signal ceases to be subjected to interference and other interference. The optical signal does not lose its original quality even when transmitted over long distances. MP3 players with optical output provide the ability to listen to audio in high quality. The vast majority of MP3 players with a TOSLINK connector are premium models that can satisfy the needs of musicians, music lovers and advanced audiophiles.

The maximum time the player can operate on one battery charge in audio playback mode. You should pay attention to this parameter first of all if you have to use the device for a long time without the ability to recharge the battery. At the same time, note that manufacturers usually indicate an “perfect” operating time: at a constant relatively low volume, without working with the screen and other additional functions that also consume battery. And this means that in fact the battery life of the player may be somewhat lower than stated. Nevertheless, this parameter allows you to fairly accurately assess the suitability of the player for long-term work without recharging, and is also quite suitable for comparing different models with each other.

The type of connector used to charge the player’s built-in battery, or more precisely, to connect an external charger. The role of such a device can be played by a network or car adapter, a power bank, or even a USB port of a PC or laptop. As for specific connectors, the most common options are:

- microUSB. A smaller version of the USB connector designed for portable devices. It appeared quite a long time ago, but does not lose popularity in our time and is used by many manufacturers.

- MiniUSB. Similar to the connector described above, which differs only in the size and shape of the socket - for this interface they are slightly larger than for microUSB. Because of this, the connector is less common.

- USB C. A miniature USB connector, positioned, among other things, as a potential successor to microUSB. Unlike its predecessor, it has a double-sided design, thanks to which the plug can be inserted into the socket on either side.

— Lightning. Apple branded connector. Like USB C, it has a reversible design, while being somewhat more convenient and reliable, but the use of Lightning is limited to products from Apple itself.

- Branded. A connection connector that does not belong to generally accepted standards and is used to a limited extent - in equipment from one or several manufacturers. However, due to general standardization, this option has practical...ly disappeared from the scene.