Maximum memory card / flash drive capacity
The maximum size of the memory card or USB stick (see "Media type") that the radio can work with normally.
High-capacity drives require fairly high processing power and may use special technologies that are not supported by all radios. This is the reason for the limitation on the volume of supported media.
Resolution
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).
Number of bands
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.
Number of fixed settings
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.
High Pass Filter (HPF)
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).
Low Pass Filter (LPF)
The ability to adjust the low cut without affecting other frequency ranges. Thanks to this, you can completely remove low frequencies (for example, for salon acoustics, when the subwoofer is “responsible” for the bass), without affecting other frequencies. This way of adjusting is much easier than adjusting individual EQ bands (see above).
Bass Boost function
A function that enhances the bass sound. In some way similar to the equalizer, however, unlike it, when using BassBoost, the bass boost is turned on and off with literally one touch of a button — this is more convenient and safer than fiddling with the equalizer settings.
Video output (composite)
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).
Subwoofer output
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.
