Comparison Pioneer SPH-DA240BT vs Kenwood DMX-7017BTS

Diagonal display size of car radio. The larger the screen, the larger the image on it and the better, usually, information is perceived; in addition, large size is important if the screen is touch-sensitive (see Touch screen). On the other hand, in car radios, the display size is limited by mounting dimensions and almost never exceeds seven inches.

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).

— Android OS. Firmware based on Android OS significantly expands the capabilities of the radio, essentially turning it into a portable computer. Such firmware not only itself contains an extensive set of software, but also allows you to install additional applications for a wide variety of purposes. At the same time, unlike other devices running this OS, the ability to connect to the Internet for Android radios is far from mandatory - many models do not have Wi-Fi/3G/4G modules or the ability to connect the appropriate adapters. But the presence of Bluetooth and/or GPS (see below), as well as a touch screen, is almost mandatory in such devices (although exceptions are possible here).
It is also worth noting that there are models on the market with different versions of Android ( Android 7, Android 8, Android 9, etc.). The newer the OS ( Android 10 or Android 11), the more advanced it is overall, but in this case there is no point in describing in detail the differences between the versions. The fact is that radio tape recorders often use highly modified editions of Android, and the differences between versions are often insignificant compared to the differences between specific editions, even within the same version. But what this parameter directly affects is comp...atibility with specific software: many applications have restrictions based on the oldest version of Android on which they can be run. But we should not forget that at the time of release the device could have had one version of the OS, and at the time of sale it could have been updated to a more modern one.

- Windows CE 6.0. A special edition of the Windows operating system, designed for use in embedded and compact equipment, including car radios. In general specifications, it is similar to Android described above, but today it is outdated - official support was discontinued back in 2018. Therefore, models running this OS are rare and most often represent early models of standard radios (see “Mounting size”).

— GPS module. The built-in GPS satellite navigation module allows you to determine the current location of the device; but the further use of this data may vary, depending on the specific model. Most radios with such equipment are quite advanced devices with large color screens on which cards are clearly visible. Thus, the presence of GPS at least allows the device to work as a navigator. In addition, there may be other options for using this function, including quite specific ones - for example, adding coordinates to a video captured in DVR mode(see below) and even searching for nearby friends from social networks.

— DVR mode. The ability to use the radio as a DVR - more precisely, the main unit of the DVR, because To work, you will also need an external camera. In this mode, the radio tape recorder works for recording, recording the video captured by the camera onto a USB device, memory card or other drive. Such a video can be very useful in case of an incident on the road - for example, as evidence in a traffic accident case. As a rule, models with this function have some special features of full-fledged recorders - auto-start recording, cyclic recording, etc.

— Connecting parking sensors. The ability to connect parking sensors to the radio - a device that allows you to determine the distance to an obstacle in the car’s blind spot (for example, directly in front of the front and rear bumper). Parking sensors make parking and maneuvering in tight spaces much easier; It is often more convenient to display data from its sensors not on a separate internal unit, but on an existing radio.

— Bluetooth. A technology designed for direct wireless communication between various devices. Can be used for various purposes. In car radios, the most popular options are, in particular: live audio broadcast from a smartphone, tablet, etc. for car acoustics; operation of the radio as a car kit during a telephone conversation (when the subscriber’s voice is broadcast through the same acoustics); remote control of the player on a connected device from a radio, etc. The specific Bluetooth functionality depends on the model; it should be clarified separately in each case.

— Wi-Fi module. The presence of a Wi-Fi wireless communication module in the car radio. This technology was originally created for creating wireless computer networks (including for the purpose of connecting to the Internet), but recently it can also be used for direct communication of various devices with each other. The ways to use this function in car radios may vary. Thus, some models support a classic communication to Wi-Fi access points to access the Internet - similar to how this is done in tablets. Others are able to connect directly, for example, to a smartphone for remote control and exchange of various data. And radio tape recorders with a 3G modem (see below) may even provide the ability to “distribute” mobile Internet to other Wi-Fi devices nearby.

- 3G ready. Possibility of connecting an external modem for 3G mobile networks to the radio. For more information about the 3G communication itself, see below; Let us note here that its support significantly affects the price of the entire device, although it is not always required. In light of this, radios are produced that are not equipped with their own 3G modem, but allow the communication of an external adapter. Such models are suitable for those who are not sure whether they will need a 3G communication: you can purchase a radio without overpaying for the built-in modem, and if necessary, purchase an adapter separately. However, it is worth considering that an external modem usually occupies a USB port, which can create difficulties with connecting flash drives and other peripherals.

— 3G modem. Built-in mobile communication module designed for third generation 3G (UMTS) networks. The options for using such a communication may be different, depending on the specific radio: listening to music and watching videos from the Internet, accessing cards or map updates (in devices with GPS, see above), and in some models even voice calls and a full-fledged web surfing. The data transfer speed can be up to 70 Mbit/s (in practice, most often up to 10 - 15 Mbit/s), which is comparable to a fixed Internet communication. At the same time, the third generation is gradually being replaced by even faster 4G communications (see below), but for radio tape recorders, in most cases, 3G is sufficient (especially since such modems are relatively inexpensive).

- 4G ready. Radios with the ability to connect an external 4G adapter. Completely similar to the 3G ready models described above, except that in this case we are talking about 4G (LTE) communications; about it, see below.

— 4G (LTE) modem. Built-in mobile communication module designed for 4th generation 4G LTE networks. The application is completely similar to the 3G modem described above (and can even work in 3G networks in the absence of LTE coverage). The main difference is that 4G networks provide even higher communication speeds - up to 173 Mbit/s, and in the future even higher. On the other hand, 4G networks are not yet as widespread as 3G, so before buying a radio with such a modem, it doesn’t hurt to make sure there is LTE coverage in your region.

— NFC chip. Auxiliary wireless communication module with short range (up to 10 cm). In car radios it is mainly used to facilitate wireless communication with another device via Wi-Fi or Bluetooth: instead of setting up the communication, you just need to bring an NFC-compatible device (for example, a smartphone or tablet) to the radio chip and confirm the communication. There are also other ways to use this technology - for example, automatically starting music playback from a smartphone when you bring it to the radio. However, such methods are less common, and their set depends on the specific model of the radio and the capabilities of external devices.

— DAB radio. The radio can receive digital radio broadcasts. The main differences between such broadcasting and analogue (for example, FM) are high sound quality, almost complete absence of interference and extensive capabilities for transmitting additional information - text and even video. In addition, the signal quality does not deteriorate as the transmitter power decreases: the signal is either present in its pure form or not at all. It is worth considering that digital radio broadcasting is still much less common than analogue. In addition, in addition to the original DAB, there is an expanded DAB+ standard; Moreover, “plus” tuners are compatible with regular DAB broadcasting, but not vice versa. Therefore, before purchasing a device with this function, it would not hurt to check whether there is digital broadcasting in your region and whether the radio tuner is compatible with it.

- AirPlay support. The radio is compatible with AirPlay technology. This technology is used in portable Apple gadgets for wirelessly streaming music and video to external devices; Accordingly, it makes sense to pay attention to models with this function if you plan to use the radio with an iPhone or other Apple device. However, compared to another proprietary Apple technology - CarPlay - this technology has more limited capabilities; it is intended exclusively for broadcasting content. On the other hand, AirPlay is much cheaper and can be provided even in relatively simple and inexpensive radios.

- MirrorLink support. The radio supports MirrorLink, a technology designed to connect smartphones to car multimedia systems. The idea of MirrorLink is that a mobile device runs various applications (for example, navigation or a player), and the driver and passengers can interact with them (control, receive information) through the on-board equipment of the car - a touch screen and a radio control panel, a remote control on steering wheel, etc. This technology is supported primarily by premium smartphones running Android.

- Dual Zone. This function allows you to use the radio to play two sound sources simultaneously, with one of them outputting to the front and the other to the rear speakers of the car's sound system. Thus, it is possible to separate to a certain extent what the driver and passenger will hear: for example, music or sound from a video player can be broadcast to the rear seats, and a radio broadcast with a news program or a report on road conditions can be broadcast to the front seats. Volume adjustment is also carried out separately. The Dual Zone function will be useful primarily in minivans and other cars with spacious interiors, as well as in luxury cars.

- MHL support. MHL technology is used in portable devices to transmit digital audio and video signals through a universal connector such as microUSB or USB Type C; This eliminates the need for separate video outputs and has a positive effect on compactness. The bandwidth of this communication is similar to HDMI, it is sufficient even for HD resolutions. Specifically for a car radio, MHL support means that you can connect an MHL-compatible gadget to this model and take advantage of all the capabilities of this technology. And they include both video and audio broadcasting, as well as additional functions - in particular, charging the gadget’s battery and controlling it through the touch screen of the head unit. In the radio itself, to work with MHL, you can use either a compatible HDMI port or another connector - for example, USB.

The ability to adjust the high cut without affecting other frequency ranges. Thanks to this, you can improve the overall timbre of the sound by completely removing the high frequencies, if necessary (for example, for a subwoofer). Moreover, this method of adjustment is much simpler than adjusting individual equalizer bands (see above). Typically, this function is combined with bass control (see below).

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).

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.

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

Composite video input is usually an RCA connector ("tulip") of a characteristic yellow color. It can be used to connect any video source with an appropriate output, such as a portable DVD player. Note that in this case, only the input intended for working with video is meant; to output sound, you will have to use another interface, for example, a linear one (see above). The image quality when connected via a composite connector is relatively low, HD resolutions are not supported, but this can hardly be called a serious drawback, given the characteristics of displays in modern radios (and separately made car TVs / monitors, which can broadcast a signal from the radio).

The more composite video inputs provided in the radio, the more signal sources can be connected to it simultaneously.

Input for receiving analogue video signal in RGB format (“blue-green-red”, each colour has its own channel). To transmit such a signal, different types of interfaces can be used, but in car radios, a small plug of a round or oblong shape is most often found; the specific option should be clarified according to the official documentation. The RGB input is used most often to connect navigation modules.