Comparison Panasonic SC-DM504EG vs Panasonic SC-DM502

- Music Center. Music centers are stationary audio systems, including a player, amplifier and acoustics; Their distinctive feature is the speakers, made separately from the main unit. Some models may provide mounts for installing speakers on the main unit, but these mounts are quick-release, and the length of the wires allows you to place the speakers separately.

- Minisystem. Minisystems are relatively small devices made in one-piece housings; Despite their small size, they are usually designed for stationary use, although they may have independent power supplies (see below). The functionality of mini-systems can be different: some models, in fact, are speakers with slightly expanded capabilities, in others these capabilities can be comparable to full-fledged music centers and even have wireless charging.

— Radio tape recorder. The radios have a distinctive design reminiscent of cassette recorders; and some of them are even capable of working with cassettes, see "Media". Like the music centers described above, such devices have everything you need for listening - a player, an amplifier and acoustics; however, the speakers are made non-removable, and the functionality of radio tape recorders is usually more modest. On the other hand, such models are portable and can even be used to play music on the go - almost mandatory f...eatures of radio tape recorders are the presence of a handle for transportation and the ability to be autonomously powered (see below) from replaceable batteries.

— Floor system. The purpose of audio systems of this type is already clear from the name: they are initially designed for installation on the floor. This installation allows you to create fairly large devices with powerful acoustics; in fact, most floor-standing audio systems are actually a set of speakers with a built-in player. However, there are also quite compact models of this type that allow desktop or wall installation with the stand disconnected.

- For parties. Audio systems for organizing incendiary musical parties with friends and family. Such models are capable of sounding a vast space both indoors and on the street dance floor. Often, audio systems for parties are complemented by built-in lighting effects to create a disco atmosphere; microphones can also be connected to them, which karaoke lovers will appreciate. Alternative names for such audio systems are Party speaker or PartyBox.

— For musicians. Advanced speakers without light and music with good sound quality, especially for musicians who give performances on the street or participate in outdoor events. Such models are not intended for full-fledged concerts, but rather for “live” performances in public places. Audio systems often include the ability to connect musical instruments, and they are often equipped with a suitcase-type handle for ease of carrying the equipment. If it falls under the above, but there are lighting effects - For parties.

— Smart speaker. Audio systems in the form of relatively small single speakers with “smart” control electronics. For such devices, four key features can be distinguished: Internet connection (usually via Wi-Fi), synchronization with a smartphone or tablet (usually the same), support for voice commands and advanced functionality. In fact, smart speakers are not classic audio systems, but universal “assistants” with speakers for playing music; and the voice control capabilities in them go far beyond the “musical” functions. Thus, many models allow you to set a timer or alarm on a smartphone, control smart home components, receive help on a variety of requests, etc. At the same time, contextual recognition of commands is often supported, with the ability to process complex requests like “put on the band I listened to yesterday In the evening".

The number of radio stations that can be stored in the tuner's memory.

By itself, the memory greatly simplifies the work with the tuner. Instead of having to manually search for your favorite stations each time, it is enough to “remember” them and in the future simply select the desired wave from the list in the receiver’s memory. The number of memory cells in modern audio systems can reach several tens; this will be especially useful for residents of metropolitan areas, where there are many stations on the air, as well as for those who often have to travel and tune the receiver to local frequencies.

Tuner support for Radio Data System technology. This technology is used mainly in the FM band; it allows, in addition to the sound signal, to transmit additional textual information by radio — for example, the names of broadcast compositions, announcements, advertising messages, etc. For RDS-enabled audio systems, this information is shown on the display.

Nominal sound power (see "System power") on each of the main channels of the audio system. This indicator is most often indicated in models with a subwoofer (see "Number of channels"); knowing it, you can estimate the power distribution between the main speakers and the subwoofer.

The phase inverter is a tube installed in the column housing and having an outlet to the surrounding space. The length of the tube is chosen so that a signal comes out of the outlet, inverted in phase relative to the signal from the front of the diffuser. This enhances the sound pressure and improves the sound of the speakers, including at low frequencies. Note that such audio systems should be placed at a certain distance from walls, furniture, etc. — otherwise, a hum may occur due to the movement of air through the phase inverter tube.

A similar function in some models is performed by a passive radiator (see below).

— RCA. The RCA interface uses coaxial cables with characteristic "tulip" plugs and corresponding connectors. It can be used to transfer different types of data, however, in this case, it means connecting the audio signal from the preamplifier in analogue format, one channel of audio per connector. RCA is widely used in modern audio technology, but its resistance to interference is very limited.

— Mini-Jack(3.5 mm). Standard connector for most modern portable audio equipment. In audio systems, it is mainly used to connect such equipment — primarily pocket media players. It uses analogue signal transmission, while the resistance to interference, like RCA, is not high, and the quality may even be lower due to the fact that both channels of stereo sound are transmitted over the same cable.

— Coaxial S / P-DIF. An electrical version of the S / P-DIF standard, using a coaxial cable with a “tulip” connector for signal transmission. Do not confuse this interface with the analogue RCA described above — despite the identity of the connectors, these standards are fundamentally different: "coaxial" works in digital format and even multi-channel audio can be transmitted over a single cable. Compared to optical S/P-DIF, this interface is less resistant to interference, but more reliable because electrical cables are not as delicate.

— Optical. One of the va...rieties of the S / P-DIF standard is, along with the coaxial one described above. In this case, the signal is transmitted via a TOSLINK fibre optic cable. The main advantage of this interface is its complete insensitivity to electrical interference, while its capabilities are sufficient even to work with multi-channel audio. Among the shortcomings, it is worth noting the high price of connecting cables, as well as the need for careful handling of them.

— Under the microphone. Input for connecting a microphone to an audio system; can use different types of connectors (3.5 mm mini-Jack, 6.35 mm Jack, etc.). This function is mandatory for models with karaoke (see "Advanced"), but can be used for other purposes.

— Instrumental. Connectors used to connect musical instruments (acoustic or bass guitars, keyboards, etc.). Most often they are made in the form of 6.35 mm Jack format sockets. The audio signal from pickups has its own specific characteristics, so the instrument input typically features a higher input level and special impedance matching to ensure optimal sound quality.

The presence in the audio system of its own LCD display. Such displays may have different characteristics: in some models, these are the simplest indicators in which symbols are made up of separate luminous fragments (similar to how numbers are made up of separate “sticks” in the simplest electronic watch); in others — full-fledged matrices with an image formed from pixels. However, anyway, the display makes the control of the audio system more convenient and intuitive, because. can display various additional information — the selected signal source, track name, RDS data (see above), equalizer settings, error messages and much more.

The ability to use the audio system to charge devices connected to it – pocket audio players, mobile phones, etc. For this usually a USB port is used (microUSB or USB-C in modern models); some models are able to play music from an external gadget right in the process of charging.