| Composition | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Tuner | has a digital | has a digital |
| Cassette deck | | yes |
| CD players | no | yes |
| MP3-players | yes | no |
| DVD-player | no | |
| Blu-ray player | no | no |
| Amplifier | yes | yes |
| Equalizer | yes | yes |
| Navigator | no | no |
| TV tuner | no | |
| General characteristics | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Nominal and maximum power | 4x30 W/4x50 W | 4x22 W/4x47 W |
| Management changer | | CD |
| CD-changer interface is | no | custom |
| Size | 1 DIN | |
| Color | black | |
| Supported carriers and formats | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Formats | MP3, WMA, AAC, FLAC | CD-Audio |
| Media | iPod | cassette |
| Display | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Display type | monochrome | multicolor |
| Adjust backlight brightness | | yes, automatic |
| Cassette deck | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Auto tape | | yes |
| Noise reduction | | DolbyB |
| Auto reverse | | yes |
| To search for music on cassette | | yes |
| Skip pause on the tape | | yes |
| Management | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Search for a folder/file | yes | |
| Auto plants | yes | |
| Multicolor lighting | | yes |
| Infrared remote | no | yes |
| Joystick on the steering wheel | it is possible to connect | no |
| Pause when speaking on the phone | | yes |
| Memory disk names | | yes |
| Interfaces | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Inputs | USB | |
| Front panel USB | yes | |
| Audio input on the front panel | yes | |
| Bluetooth Support | no | |
| Outputs | audio | audio |
| Connecting the ISO | | yes |
| Gold-plated connectors | | yes |
| Protection | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Detachable panel | | yes |
| Tuner | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| Switching stereo/mono | yes | |
| Tuner with long reception | yes | |
| Number of preset FM/AM | 18 / 3 | |
| Support band | FM, MW, LW | FM, MW, LW |
| RDS | RDS RDS/EON, RDS, PTY | RDS |
| Additional information | KENWOOD KMM-257 | KENWOOD DPX-4020 |
| ID3 tag support | yes | |
| Super-bass | | yes |
| Adjusting the voice | yes | yes |
| Weight | 640 g | |
| Disabling voices | | yes |
| Single-bit DAC architecture | | yes |
| CD-text | | yes |
| Resampling audio | | 8 |
| Tone compensation | yes | yes |
| Dimensions (WxHxD) | 182x53x107 mm | 180x100x160 mm |
| Features | | Sleep timer (20/40/60 min). Possibility to change the button illumination. Calendar with memory. System of memorizing the audio settings. Playback of CD-R/RW discs. Tape counter. |
