Comparison Panasonic SC-PMX70 vs Panasonic SC-PM250

Radio bands accepted by the music centre tuner. To date, the most common support for such ranges:

— FM. Part of the ultra-short wave (VHF) band between 87.5 MHz and 108 MHz. It uses frequency modulation, which allows you to broadcast music in stereo with a fairly high sound quality, as well as transmit RDS signals (see RDS). At the moment, most music radio stations in the CIS broadcast in this range, as a result of which FM is supported in the vast majority of audio systems. The disadvantage of this option is the limited reception area — a maximum of several tens of kilometers from the transmitter — so FM broadcasts can usually be listened to within the same city and surrounding areas.

— AM (from the English amplitude modulation — amplitude modulation) — broadcasting using amplitude modulation. Usually this term means broadcasting on medium waves in the range of 520-1610 kHz; most consumer AM receivers are designed for these same frequencies. The reception range of AM stations can be hundreds of kilometers, but the sound quality is lower than on FM, so this format is broadcast mainly by “talk” and news radio stations.

— VHF. In this case, the sub-band 65.9-74 MHz is meant, using the so-called OIRT modulation. In this format, VHF broadcasting was originally conducted in the countries of the Soviet Union and Eastern Europe, but at the moment it is not very popular due to the development of FM. VHF is technically similar to FM (see above), the...main differences are the occupied frequency band and the inability to transmit RDS signals in VHF (see RDS).

— DAB+. DAB is an abbreviation for Digital Audio Broadcasting, i.e. "digital broadcasting"; and "+" means an improved version of this standard. Formally, DAB + is not only a range, but also a signal transmission format: unlike all the options described above, it, as the name implies, is digital. This gives a number of advantages over traditional transmitters — in particular, a greater range with less power and high quality of the broadcast sound. In addition, this sound is practically not subject to distortion: weak interference does not affect its quality, and when the transmitter power is critically reduced, the signal is not distorted, but disappears entirely. The latter, however, can be written down as disadvantages; but the really significant drawback of this option is perhaps its low prevalence (so far) in the CIS countries. Technically, such broadcasting can be carried out in any band above 30 MHz, but in fact several options are used (depending on the country) related to the VHF band. Note that DAB+ tuners are capable of receiving original DAB radio broadcasts, but not vice versa.

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.

The total sound power provided by the audio system at maximum volume, in other words, the total power of all the speakers provided by the device (including the subwoofer).

The higher the power, the louder the system will sound and the larger the area it can cover. On the other hand, high power significantly affects the price, dimensions, weight and power consumption of the device. In addition, when evaluating and comparing according to this indicator, it is worth considering some nuances. Firstly, some manufacturers go to the trick and give in the characteristics not the average, but the peak sound power; such numbers can be quite impressive, but they have very little to do with real loudness. So if it seems to you that the claimed power is too high, it's ok to clarify what exactly is meant in this case. Secondly, when comparing, it is worth considering the presence of a subwoofer — it plays an auxiliary role, but it can account for more than half of the total system power. Because of this, for equal total power, a device with a subwoofer may be quieter than a model without a subwoofer: for example, a 2.0 40W system will have 20W per main channel, while a 2.1 40W model may have 20W per subwoofer, and only 10 watts for the main speakers.

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 number of distinct frequency ranges (bands) into which sound is divided when played through the acoustics of an audio system. For each such band, a separate speaker is provided, and sometimes several.

The simplest option provides 1 lane; it is very popular in modern audio systems, because. requires a minimum number of speakers, and the sound quality can be quite good. More advanced options provide 2-3 bands (low and high frequencies, or bass, treble and medium), and in high-end models, the number of bands can be up to five. Note that, in addition to integers, models are also produced with a fractional number of stripes — for example, 2.5 or 3.5. This marking indicates the presence in the design of a speaker responsible for two bands at once: for example, model 2.5 has separate speakers for bass and treble plus a combined bass + midrange (similar in design to bass, but also loaded with mid frequencies).

Anyway, the abundance of bands, usually, indicates a high class of acoustics: the more separate frequency ranges, the narrower the specialization of each speaker, the more accurately it is able to reproduce its part of the signal, and the more complex the system is.

The term "impedance" refers to the resistance of a speaker system to alternating current. Note that in the case of audio systems, this parameter plays a secondary role: it is important for selecting acoustics for an amplifier, and here both of these components are in most cases optimally matched by the manufacturer to each other. Therefore, in fact, information about the impedance can be useful only when looking for speakers to replace the complete ones: it is highly desirable that the new acoustics have the same impedance as the standard ones.

— Airplay. AirPlay technology was developed by Apple. It is based on Wi-Fi and is used to wirelessly broadcast content from Apple devices to external audio systems. Thus, this function is useful for those who want to connect an iPhone or iPod touch to the audio system, but do not want to fiddle with wires; however, it is possible to connect via AirPlay and other devices - for example, a PC with iTunes and a Wi-Fi module installed.

— Airplay 2. The second generation of the AirPlay technology described above, introduced in 2018. Among the main innovations of this version is support for the "multi-room" format, that is, the simultaneous transmission of several audio signals to different compatible devices installed in different places. In this way, you can, for example, turn on the radio broadcast of a news programme in the living room, relaxing music in the bedroom, etc. In addition, AirPlay 2 received a number of other improvements - improved buffering, the ability to stream to stereo speakers, as well as support for voice control through Siri.

— Chromecast. The original name is Google Cast. A technology for broadcasting content to external devices developed by Google. Allows you to transmit an audio signal from a PC or mobile device to the audio system, broadcasting is standardly carried out via Wi-Fi, while the receiver and signal source must be in the sa...me Wi-Fi network (Chromecast media players are an exception). Note that in signal sources (smartphones, tablets, PCs, etc.), Chromecast is implemented at the level of individual applications. For example, at the time of its creation, this feature was available, among others, in the YouTube and Netflix apps for Android and iOS, as well as in the web versions of these apps for Chrome. Thanks to this format, this technology is extremely widespread in our time, and the ability to connect a particular gadget to an audio system with a Chromecast is usually limited to the ability to install appropriate applications on this gadget.

— DLNA. DLNA (Digital Living Network Alliance) is a standard that allows you to combine various types of home electronics and home appliances into a single network for content sharing and management. In the case of audio systems, DLNA can be used, for example, to play music from a computer disk connected to such a network, broadcast sound to a device installed in another room (for example, an amplifier), etc. Connection to DLNA can be carried out both wired and wirelessly (according to the Wi-Fi standard), and the compatibility of devices does not depend on their manufacturers - the only condition is compliance with the DLNA standard.

-LAN. Standard interface for wired communication to local computer networks based on RJ-45 connector. Its presence allows you to use various network features such as Internet radio (see "Advanced") or DLNA (see above). Compared to another network interface - Wi-Fi - LAN is less convenient due to the presence of wires, but it is more reliable and provides a higher actual data transfer rate.

- WiFi. The presence of a Wi-Fi wireless module in the design of the audio system. This technology is used both in computer networks and for direct communication of various devices with each other; its "range" is enough to work within residential premises, even through walls. In this case, Wi-Fi can be used to work with network features such as Internet radio or DLNA(see above). At the same time, this option is more convenient than wired LAN, due to the absence of actual wires. In addition, support for this technology is a prerequisite for using the AirPlay and Chromecast features (see above); and in some devices, Wi-Fi even allows you to connect smartphones, tablets and other gadgets as remote controls.

One of the most modern and fastest standards of this wireless communication technology is Wi-Fi 5. The 802.11ac version uses the 5 GHz band (less crowded and more less noise-resistant than 2.4 GHz), providing speeds of up to 1.69 Gbps per antenna and up to 6.77 Gbps with multiple antennas.

— Bluetooth. Direct wireless communication technology between different devices. One of the most popular ways to use Bluetooth in audio systems is to work with an audio signal, primarily broadcasting sound to wireless headphones or speakers; and some models also provide the ability to connect a smartphone, tablet or other device and use the audio system as an external Bluetooth speaker. True, it should be borne in mind that initially Bluetooth is noticeably inferior to a wired communication in terms of sound quality; however, in our time, this shortcoming is often compensated by the use of one or another version of the aptX codec(see below).
In addition, other options for using Bluetooth may be provided - for example, file sharing between the built-in memory and the same smartphone, or remote control via an application. They are not mandatory for modern audio systems, but with the development of technology they are becoming more common.

In modern audio systems, the Bluetooth v 5 standard is most often used. Its important innovation is the expansion of the capabilities of the BLE (“Bluetooth Low Energy”) mode: if necessary, the device can increase the range by reducing the speed, or speed up transmission at the cost of reducing the range. In addition, a number of improvements have been introduced regarding the simultaneous operation of several connected devices.

- Support for aptX. Support for audio system aptX - a codec designed to improve the quality of sound transmitted via Bluetooth. Accordingly, this function automatically means the presence of a built-in Bluetooth module (see above). The need to use special technologies is due to the fact that in the original Bluetooth format compresses the audio signal very strongly, which significantly affects the final sound quality. aptX technology is designed to remedy the situation: according to the creators, it provides sound purity, "comparable to Audio CD (16-bit / 44.1kHz)" and almost as good as a wired communication. This is often enough even for comfortable listening to lossless formats, not to mention MP3 and other popular compressed formats. Of course, in order to use aptX, the signal source must also support it.

- Support for aptX HD. Support for the aptX HD codec by the audio system, an improved and updated version of the aptX described above. This version claims sound clarity comparable to Hi-Res (24-bit/48kHz) audio material; this allows you to comfortably listen not only to MP3, but also to lossless formats and even uncompressed audio materials. On the other hand, aptX HD support is quite expensive, and its advantages over the original aptX become noticeable only on very high-quality audio materials, for which consumer audio systems are rarely used. Therefore, this function has not received much distribution.

— AAC. A codec used primarily in Apple portable devices to improve sound transmitted via Bluetooth. In this sense, it is similar to aptX (see the corresponding paragraphs), but is noticeably inferior to it in terms of capabilities: if the sound of aptX is compared with Audio CD, then AAC is at the level of an average quality 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 it makes sense to provide in wireless headphones - further improvement will simply be imperceptible to the human ear.

- Network audio streaming. The ability of the audio system to work with network streaming (streaming) audio services like Deezer, Spotify, Tidal, etc. Such services are designed to broadcast content (in this case, mostly music) over the Internet; in this case, the files being played are not stored in the audio system, but are played directly from the corresponding resource on the World Wide Web. Nowadays, there are many streaming services that differ in the range of music and access conditions; a specific list of supported services should be specified separately. However, in any case, the main advantages of online streaming can be called an extensive selection of content and almost instant access to the desired composition; some services can also act as a radio, automatically selecting music according to the manufacturer's preferences.

- Speakerphone. Ability to use the device as a hands-free system for a mobile phone. In this mode, the audio system is connected to the device, most often via Bluetooth (see above), and the voice of the subscriber at the other end of the line is output not to the phone, but to the speakers of the audio system. This is often more comfortable than holding the phone to your ear; in addition, the speakerphone is useful if several people need to participate in a conversation.

- NFC chip. NFC is a short-range wireless technology (about 10 cm). In audio systems, NFC is mainly used to facilitate communication using the Wi-Fi or Bluetooth standard (see above). With this chip, you can simply bring an external NFC-compatible device to the audio system and confirm the communication - it's easier than manually configuring settings.

- Docking station for Android. The presence of a docking station for connecting portable electronics (primarily smartphones) based on the Android operating system. In fact, the dock is a socket-stand, supplemented with a special plug; thanks to this, it not only provides a communication, but also allows you to install an external device directly on the audio system, which is quite convenient. We also note that such a communication often provides additional features - for example, controlling the player on a smartphone from the audio system remote control. However, when choosing a model with this function, it should be borne in mind that Android devices are very numerous and diverse; in practice, this means that before buying it makes sense to make sure that your gadget is compatible with the audio system.

— 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.

— RCA. The RCA interface uses coaxial cables, with characteristic "tulip" plugs, and the corresponding connectors. It can be used to transfer different types of data, however, in this case, it means outputting an audio signal 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). One of the standard connectors in modern audio equipment, it is widely used in portable devices, as well as for connecting headphones. However, we note that in this case we mean the jack responsible for the line output — an interface for transmitting an audio signal in analogue format to an external device, such as an amplifier. The headphone jack is listed separately in our catalog, even if it belongs to the 3.5 mm mini-Jack standard; See below for details on headphone output.

— 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 rel...iable because electrical cables are not as delicate.

— Optical. One of the varieties of the S / P-DIF standard is, along with the coaxial one described above. In this case, the signal is transmitted via a TOSLINK fiber 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.

— Subwoofer. A separate output for connecting an external subwoofer — a specialized low-frequency speaker. The use of such a speaker allows you to significantly improve the sound of low frequencies, make the bass powerful and rich, which general-purpose speakers are not capable of. Note that such an output can also be useful in systems with a built-in subwoofer — external "subwoofers" are in most cases more powerful and provide more options for adjusting the sound.

— Headphones. Separate headphone output. Most often, a standard 3.5 mm mini-Jack or 6.35 Jack is used for this purpose, but there may be other options — for example, a manufacturer's proprietary connector. Anyway, headphones can come in handy in situations where you need to keep quiet — for example, if you want to listen to music at a late time when others are already sleeping — or vice versa, in noisy environments when ambient sounds drown out the speakers of the audio system.

— Composite. The full-size composite interface includes three connectors — one for video transmission and two for left and right stereo channels. However, in this case, a composite output usually means only a video connector (the standard acoustics of the audio system are responsible for the sound, it usually makes no sense to broadcast it to a TV). Anyway, this output allows you to connect the audio system not only to the latest, but also to frankly outdated TVs. Its disadvantages are poor image quality and incompatibility with HD.

— Component. Output for transmitting video signal in analogue format. Outwardly similar to the composite interface described above, because also uses three RCA cables; however, in this case, these cables carry three components of the video signal (hence the name). The component interface is considered the most advanced among the popular analogue video standards, it provides the highest image quality among them and is even capable of working with HD resolutions. Among the shortcomings, it is worth noting the impossibility of transmitting sound — this will require a separate connection.

— S video. Analogue interface for video transmission. In some way similar to the component described above, since it also provides separate wires for transmitting video signal components; however, in this case there are only two of these wires. This, on the one hand, allowed us to limit ourselves to one connector instead of several, on the other hand, it slightly reduced the quality of the “picture” and limited the bandwidth, so HD is out of the question with such a connection.

— SCART. Universal audio/video interface using a characteristic large 21-pin connector (20 pins plus a rim around the connector). For a long time it was the standard for European video equipment, but today it is considered obsolete due to its low bandwidth and significant dimensions. Note that SCART can work with signals of different formats, which allows the use of adapters — in particular, for connecting external devices via composite and component interfaces.

— HDMI. Universal digital interface that allows you to transfer HD-video and multi-channel audio over a single cable. It is practically a standard for modern video equipment, in particular, it is present in most TVs. In audio systems, this type of output is used in the same way as the coaxial S / P-DIF described above — that is, to output the audio signal in digital form.