Comparison Philips AZ-783 vs Panasonic RX-D55

The type of cassette deck provided in the audio system.

The cassette deck is a device for playing magnetic audio cassettes. This type of media is considered completely obsolete, but some users still have quite a significant stock of such cassettes. Thus, some audio systems are still equipped with this feature, but nowadays decks are usually single cassette; two-cassette solutions, which allow you to transfer music from cassette to cassette, have practically fallen into disuse.

Radio bands received by the tuner of the music center. Today, the most common support for such ranges is:

- FM. Part of the ultra-short wave (VHF) range ranging from 87.5 MHz to 108 MHz. Uses frequency modulation, which allows you to broadcast music in stereo format with 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 nearby environs.

- AM (from the English amplitude modulation - amplitude modulation) - radio broadcasting using amplitude modulation. Typically this term refers to medium wave broadcasting in the range 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 mainly broadcast by talk and news radio stations.

- DAB+. DAB is an abbreviation for Digital Audio Broadcasting, i.e. “digital radio broadcasting”; and “+” means an improved version of this standard. Formally, DAB+ is not only a band, but also a signal transmission format: unlike all the options described above, it is, as the name suggests, digital. This provi...des a number of advantages over traditional transmitters - in particular, longer range with less power and high quality of broadcast audio. 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 a disadvantage; but the really significant drawback of this option is its low prevalence (so far) in the CIS countries. Technically, such broadcasting can be carried out in any range above 30 MHz, but in practice several options are used (depending on the country) related to the VHF range. Note that DAB+ tuners are capable of receiving radio broadcasts of the original DAB standard, but not vice versa.

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.

The total frequency range reproduced by the acoustics of an audio system. Measured from the lower threshold of the lowest frequency speaker to the upper threshold of the highest frequency: for example, in a 2.1 system with main speakers at 100 – 22000 Hz and a subwoofer at 20 – 150 Hz, the total value will be 20 – 22000 Hz.

In general, the wider the frequency range, the fuller the reproduced sound will be, the less low and high frequencies will be lost due to insufficient acoustic capabilities. On the other hand, do not forget that the actual sound quality also depends on a number of other parameters — primarily the frequency response. In addition, human audible frequencies range from 16 Hz to 22 kHz; deviations from these values are very small, and the upper limit also decreases with age. Therefore, from a practical point of view, it does not make sense to provide too large a frequency range; and impressive performances like 10 – 50000 Hz, found in top-class models, are usually more of a kind of "side effect" of high-quality speakers (and at the same time — a marketing ploy) than a really significant moment.

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).

The presence of an equalizer function in the audio system.

Equalizer allows you to change the timbre of the sound by adjusting the volume for individual frequency bands. The simplest version of this adjustment provides 2 bands (high and low frequencies), but most often there are more bands. Anyway, the equalizer can be useful both for fine-tuning the sound to your own preferences, and for compensating for the shortcomings of external or standard acoustics, connected headphones, etc. - for example, if the speakers "fail" certain frequency bands. In addition, many audio systems have a set of equalizer presets (presets), usually designed for different styles of music - "Classic", "Rock", "Pop", etc. You may also be able to create and edit your own presets.

Bass boost function for powerful and rich bass. Often implemented as a single button, with which you can actually "turn the bass on and off." This is more convenient than adjusting the low frequencies using the equalizer; in addition, various special technologies can be used to enhance the bass.

— Omnidirectional sound. As the name suggests, audio systems with this feature emit sound evenly in all directions, covering a 360° space. Thus, the device can be installed in the center of the room and evenly “fill” it with sound, which will be clearly perceived at any point. On the other hand, an omnidirectional system usually sounds in 1.0 format (mono); the design may include various tricks to ensure surround sound, but such systems still fall short of full-fledged stereo in most cases.

— Voice assistant. Support of the audio system of the voice assistant. The most popular assistants nowadays are:

• Google Assistant
• Apple Siri
• Amazon Alexa

However, other solutions can also be used. In any case, it is worth noting that we are not talking about the function of the audio system itself, but about compatibility with smartphones, tablets and other gadgets that have their own voice assistants. Thus, to use the voice assistant, you will have to connect the audio system to an external device. On the other hand, the capabilities of such assistants are usually more extensive than those of built-in voice control systems (see below); advanced functions are often supported, such as natural speech recognition with complex queries (“Play the latest album of the band ... that I listened to”), voicing the weather forecast, sports results, etc. Of course, the specific set of supported commands and languages may vary - depending on the voice assistant and its version.

— Voice control. A function that is practically mandatory for smart speakers (see “Purpose”) and is almost never found in other types of audio systems. As the name suggests, this control allows you to control the device using voice commands. It differs from the voice assistant (see the corresponding section) in that in this case we are talking about the simplest commands related to the main functionality of the audio system - for example, “Stop”, “Continue”, “Next track”, etc. It is worth keeping in mind that voice control almost certainly supports English, but the ability to recognize other languages should be clarified separately.

— Mobile application. The ability to control the audio system from a smartphone, tablet or other gadget with a special application installed on it. As a rule, the connection is via Wi-Fi (see "Interfaces"). The convenience of this function is not only that the system can be controlled remotely - the application is often more convenient and provides more options than the controls on the radio itself.

— Multiroom support. The device supports Multiroom technology. This technology allows you to create a single wireless network in your home from several speakers placed in different rooms, and simultaneously play music in all of these rooms. The specific features of such networks may be different in different models, they should be clarified separately. So, some devices use a Bluetooth connection, others - via Wi-Fi (directly or via a local network). In some cases, the control speaker broadcasts sound to all the others, and the same music plays throughout the house, in others, the speakers are "equal", and different tracks can be played simultaneously in different rooms. Some audio systems require an external sound source (smartphone, tablet, etc.), others are capable of playing the role of a player themselves, including for streaming Internet services.

— Karaoke.... A popular entertainment that allows users to sing their favorite songs to a backing track (musical accompaniment with the original vocals cut out) — so that the vocals superimposed on the backing track are reproduced through the acoustics of the audio system. This function requires at least one microphone input.

— Karaoke Mix. An extended version of karaoke (see above), providing various additional options — for example, assessment of performance skills in points, singing competitions, etc. As a rule, it allows you to connect two microphones.

— Internet radio. The ability to listen to Internet radio stations on the audio system. In general, such broadcasting is similar to conventional broadcasting, but it is carried out not via radio, but via the World Wide Web, which provides some additional opportunities. Thus, Internet broadcasting has no restrictions on range and range, allows you to listen to programs from any country and in any language; and the list of broadcasters is extremely extensive, among them there are both traditional radio stations duplicating their broadcasts on the Internet, and specific, purely network projects. The presence of this function assumes support for at least one network interface - Wi-Fi or LAN (see "Interfaces").

— Recording to a USB drive. The ability to operate the audio system in recording mode to an external USB device, such as a flash drive. This allows you to record your favorite radio programs from a regular tuner or Internet station (see above), copy music from optical discs, etc.; specific USB recording capabilities depend on the audio system model.

— Clock. A regular clock is a device for displaying time, most often in the form of numbers on a display. Sometimes it is precisely such a clock that turns out to be the most convenient. In addition, this function is necessary for some other features — primarily an alarm clock (see below).

— Alarm clock. A classic alarm clock that gives a signal at a set time. It can be useful not only for waking up, but also in other cases when it is necessary to warn the user about the onset of a certain time. The peculiarity of this function in audio systems is that the signal can be the switching on of a certain radio station or musical composition.

Type of independent power sourceused in the audio system. Such power is usually not the only option — it only complements the ability to work from the network.

— AA batteries. Replaceable elements of a standard size, colloquially known as "finger". Available in a variety of options, varying in quality and price, available not only as disposable batteries, but also as rechargeable batteries; sold almost everywhere. The main advantage of all replaceable cells is the ability to quickly change dead batteries for fresh ones (of course, if there is a reserve), while the original battery has to be charged — and this takes time and an external power source. As for AA, they have a relatively low power and capacity. These characteristics are sufficient for relatively compact devices; however, for models that need to power mechanical drives (for example, for CDs) and/or provide high sound power, “AA” batteries are poorly suited, and therefore are rarely used in them.

— AAA batteries. Replaceable elements, known as "mini-finger" or "little fingers". In general, they are similar to the AAs described above and differ from them only in small sizes and, as a result, less power. Because of this, such power is used only in the most compact models of audio systems, which do not require high power, but small sizes are crucial.

— Batteries C. Replaceable cells known as "Baby". The features of replaceable cells are generally desc...ribed in AA Batteries above; here we note that C batteries have a cylindrical shape and are similar in length to “finger-type” batteries, but are much thicker, due to which they are distinguished by higher power and can be used in rather “gluttonous” systems.

— D batteries. Replacement cells, the largest variety of standard cylindrical batteries used in modern audio systems. Used in the most powerful models that require a large amount of energy.

— Batteries. This parameter is indicated in our catalog in two cases: if the device uses standard replaceable elements that do not belong to any of the standard sizes described above, or if the battery size is not indicated in the manufacturer's official data.

— Accumulator. Powered by its own original battery, which is not related to standard sizes, and in some models is also non-removable. On the one hand, this option eliminates the need to constantly buy replacement batteries (or significantly spend money once on rechargeable batteries), moreover, the battery is usually supplied as a kit. However, when the charge is exhausted, in most cases the only option is to charge from an external power source — and this requires not only the presence of such a source, but also a fairly large amount of time.