| General Features | KDC-W6641U |
| DIN Size | 1 DIN |
| Detachable Faceplate | Yes |
| Protection Case For Faceplate | Yes, Soft Case |
| Faceplate Mechanism | Full Detachable Faceplate |
| Disable System Indicator (DSI) | Yes |
| Security Code Function | Yes |
| Key Illumination | Blue |
| Rotary Encoder & Control Knob | Yes |
| Operation mode | 4-Directions + Push |
| Multi control wheel | Yes |
| Attenuator with Smooth Volume Return | Yes |
| Touch Sensor Tone | Yes |
| IR Remote control | Included |
| Digital Clock (24H) | Yes |
| All-off Select (20/40/60 minutes) | Yes |
| Built-in Connector | Molex 16 pin |
| ISO connector | Yes |
| Audio Features | KDC-W6641U |
| Maximum Output Power | 50W x 4 |
| MOSFET Power IC | Yes |
| Preout | 2 |
| Preout Output Level | 2.5V |
| Preout Rear / Subwoofer Switchable | Yes |
| Subwoofer Reference Leve Adj. | Yes |
| Built-in Amplifier Cut-Off | Yes |
| Dual-Zone Source & Volume Control | Yes |
| Dual-Zone (Front / Rear) Switchable | Yes |
| Source Ton Control & Memory | Bass / Mid / Treble |
| Attenuator with Smooth Volume Return | Yes |
| System Q (Preset sound control) | Yes |
| System E's (Built-in HPF & LPF) | Yes |
| Display Features | KDC-W6641U |
| Display Type | Fluorescent (FL) Tube Display |
| Display Layout | 3 Line, Full Dot (131 x 23 dot) |
| Spectrum Analyzer | Yes |
| Dimmer Control | 2 steps - Automatic |
| Display Off Mode | Yes |
| Demo Mode | Yes |
| Special Character Dsplay | No |
| Tuner Features | KDC-W6641U |
| RDS (PI, PS, AF, TI, Clock) | Yes |
| Radio Text (RDS) | Yes |
| Radio Text Plus | Yes |
| Program Type Function (PTY) | Yes |
| Enhanced Other Networks Function (EON) | Yes |
| K3I - Clean Reception Tuner | Yes |
| FM Reception | Yes |
| AM (MW/LW) Reception | Yes |
| Presets | 24 Presets (18FM / 3LW / 3MW) |
| Automatic Memory Entry (AME) | Yes |
| Up/Down Seek Tuning | Yes |
| Tuning mode (Auto1 / Auto2 / Manual) | Yes |
| FM Stereo / Mono Selector | Yes |
| CD Features | KDC-W6641U |
| CD-R/RW Compatible | Yes |
| MP3 Playback with ID3 Tag Display | Yes |
| WMA (Windows Media Audio) Playback | Yes |
| AAC (Advanced Audio Coding) Playback | Yes |
| Kenwood Music Editor Software included | Yes |
| Multi-session Disc Playback | Yes |
| CD Text Support | Yes |
| Supreme | Yes |
| D.A.C. processing | 24 bit |
| 0 bit Mute | Yes |
| Random Function (Track/Disc) | Yes |
| Repeat Function (Track/Disc) | Yes |
| Scan Function (Track/Disc) | Yes |
| Connectivity | KDC-W6641U |
| Dual Changer Control (CH1, CH2 & AUX) | Yes |
| Bluetooth Handsfree | Yes |
| Bluetooth Audio Streaming | Yes |
| iPod Control with KCA-iP500 | Yes |
| USB Interface port | Yes |
| AUX input (5L-Bus) | Yes |
| OEM Wired Remote Control | Yes |
| 2-way (Tel/Navi) mute wire | Yes |