Comparison Sharp XL-B517D vs Sharp XL-B512

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 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.

Sensitivity determines the intensity of the acoustics response to a signal of a certain level; Simply put, the higher this figure, the higher the volume of the speaker system will be at the same signal level. 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.

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.

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.