Comparison Prology DNU-2650 vs Swat CHR-4220

Tape recorders with a shortened body.

In this case, shortened means a case that has a shallower depth than classic radio tape recorders equipped with CD drives. Due to this, such models are quite compact, which, in particular, simplifies installation and facilitates wiring. Of course, CD / DVD discs are not supported in principle by such radio tape recorders, but this is not a serious drawback — nowadays there are quite enough alternatives to such media. Also note that the shortened layout does not affect the mounting size (see above) — it can be 1 DIN or 2 DIN, and standard solutions are even larger.

Display size in dots (pixels) horizontally and vertically. The higher the resolution, the more detailed and smoothed the image is capable of producing the screen. High resolution is especially important for large diagonal displays; on the other hand, it significantly affects the cost of the device, and for a small screen it may even turn out to be superfluous (since the image will turn out to be too small).

The number of bands in the radio equalizer.

In this case, the band means a separate part of the frequency range, the volume of which can be adjusted using the equalizer independently of the other parts. The more bands the equalizer has, the more accurately it allows you to adjust the overall sound of the car radio acoustics. However, note that multi-band equalizers are quite difficult to set up, therefore they are recommended primarily for experienced users.

The number of fixed settings (presets) provided in the car radio equalizer.

The presence of such settings can greatly simplify the adjustment: choosing the right preset is easier than manually adjusting each EQ band. At the same time, presets are often selected by the manufacturer for certain genres of music and have the appropriate names — "Rock", "Pop", "Jazz", etc.; this simplifies the task even more. And the more fixed settings in the device, the wider the choice of the user. In some radio tape recorders, in addition to pre-flashed ones, user presets are also provided — they can be programmed in advance and turned on in the same way as the preset ones.

The rated sound power produced by the radio amplifier for each audio channel.

Nominal is the highest average (rms) sound power at which the amplifier operates without overload and is able to operate for an unlimited time. This is the main indicator characterizing the overall sound volume of the radio; individual power surges can be much higher than the nominal value, but they are short-lived; here we are talking about a constant signal level. In addition, compatibility with specific speakers depends on this indicator: the rated power of the speaker system must be no lower than that of the amplifier, otherwise the speakers may be damaged at high volumes. However, the spread is not so great; there are radios with an output power of 40 W, 45 W, 50 W, 55 W, 60 W and more.

Optimal amplifier power settings depend on a number of factors, ranging from the number of channels to the personal preferences of listeners. Detailed information on this topic can be found in special sources; In short, we can say that the higher the power per channel, the louder the sound the radio can produce.

— Remote control. The radio has a remote control. This function will be convenient primarily for passengers behind the driver — from the rear seats you can’t reach the radio itself. In addition, remotes often have more keys than the stock control panel, which allows you to access various additional functions on the go without digging through the settings.

— Remote control on the steering wheel. Remote control (see above) with the ability to mount on the steering wheel. Such a remote control allows the driver to control the functions of the radio without removing his hands from the steering wheel and thus not being distracted from driving the machine.

— Control from regular steering wheel buttons. The ability to control the radio from standard buttons, originally provided on the steering wheel for this very purpose. This function is similar to the steering wheel remote control described above, with the adjustment that the "remote" in this case is built directly into the steering wheel. Before buying such a radio, you must definitely check its compatibility with a particular model of car.

— Smartphone control. The presence of software (application) that allows you to control the radio using a smartphone, tablet, etc. This is not just about switching songs on the phone, but a full adjustment of all device functions.
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— Voice control. The ability to control the radio using voice commands. The implementation of such control can be different: in some models, to activate it, you need to press a button, others constantly “listen” to the environment and immediately respond to code words. Anyway, this function allows the driver to control the radio without taking his eyes off the road, which has a positive effect on traffic safety. Note that in its pure form, voice control in modern radio tape recorders is becoming less and less common, being replaced by advanced technologies like CarPlay and Android Auto (see “Control Functions”), which also include voice functions.

— Apple CarPlay system. Support for car radio technology CarPlay. This technology is designed to connect portable devices from Apple to the radio, primarily the iPhone, although it is technically possible to work with any “apple” gadget that has iOS 7.1 or later firmware, as well as a proprietary 8-pin Lightning connector. Thanks to this technology, many smartphone functions (including the Siri voice assistant, navigation, call and message management, as well as music) are integrated into the radio; using them through on-board electronics can be much more convenient than holding the iPhone in your hands. At the same time, CarPlay puts special emphasis on safety: it is designed with the maximum use of voice control, so that the driver has to be distracted by the radio screen as little as possible. For example, the mentioned messages can be dictated by voice and listened to "performed" by Siri. The connection itself is carried out by wire, through the mentioned Lightning connector.

— Android Auto system. Car radio support for Android Auto technology. Similar to the CarPlay described above, this technology is designed to combine portable devices with on-board electronics of a car — only, as you might guess from the name, in this case we are talking about gadgets running the Android OS. When you connect such a gadget, the radio actually plays the role of an external display for a mobile device, with its optimized interface and related capabilities. Features available through Android Auto include navigation (including mobile device access to external GPS antennas and modules), music control, receiving and making calls, listening to and composing SMS, and searching the Internet. Android Auto is only available for Android 5.0 Lollipop and later; in addition, if the mobile device uses proprietary firmware, its compatibility with the radio needs to be specified separately.

The number of line outputs (see above) provided in the design of the radio. It should be noted that usually these outputs use RCA connectors (“tulip”), and the analog format allows only one audio channel to be transmitted through one such. Therefore, to work with a stereo signal, two RCA connectors are required, and just a pair of such jacks is considered to be one line output - a set designed for one set of stereo speakers. The main difference between this interface and the same RCA used to connect speakers (see above) is that the line output receives a signal from a preamplifier that is unsuitable for feeding to passive acoustics. Such a signal must be sent to active speakers or an external amplifier (whereas the speaker is connected to the output of a power amplifier designed for passive speakers).

The number of composite video outputs provided in the design of the radio.

"Full size" composite interface includes 3 RCA ("tulip") sockets - one for video signal and one each for left and right stereo channels. However, other outputs are used in radios for transmitting an audio signal, so in this case we are talking only about a video output - usually it has a characteristic yellow color. The video signal via the composite interface is transmitted in analog format, its quality is average, resistance to interference is relatively low. At the same time, for connecting most car screens - for example, monitors built into the backs of the front seats - this is more than enough. And several composite outputs allow you to simultaneously connect the appropriate number of screens without the use of additional equipment (splitters).

A separate output for connecting a low-frequency speaker — a subwoofer. Ordinary speakers tend to have low quality bass reproduction; a subwoofer is used to “overlap” this range, as a result, the sound becomes much more powerful and rich. However, connecting to a regular audio output would require the use of frequency filters — so that only low frequencies enter the subwoofer. A separate output for the subwoofer eliminates the need for such devices — this connector is already filtered signal. However note that usually this interface is designed to connect an active subwoofer; passive will need a separate amplifier.