Overview: The Kenwood KDC-BT645U AM/FM CD receiver features a detachable face, front auxiliary and USB input, three pairs of 2.0-volt preamp outputs, CD changer and Satellite Radio ready controls and built-in iPod operation, as well as MP3/WMA/AAC playback. The unit also features built-in Bluetooth operation with an integrated microphone. In addition, the CD player comes with an IR wireless remote control. The unit's amplifier is rated at 22 watts x 4 channel RMS and 50 watts x 4 channel peak.

Display Features
Audio Section
Radio Functions
Disc Playback
Aux/USB/iPod Connection
Bluetooth/Remote Control
Optional Software

Display Features

Detachable Face: The unit features a single front loading CD face that detaches from the chassis to deter theft. The CD player comes supplied with a soft black fabric, draw string face case to protect the detachable face when you have it off the chassis.

Fluorescent Display: The Kenwood head unit features a 13-character white backlit fluorescent display with blue button illumination.

Display Illumination/Clock Display: When the unit is in Standby mode, the face/button illumination is "keyed." In addition, while the unit is in Standby mode, you can turn the clock display on or off. When the Clock Display is turned on and the unit is in Standby mode, the Clock Display is also "keyed." Pressing and holding the source button turns the unit off completely.

Demo Mode: This unit features a Demo mode which can be turned "on" or "off" within the menu.

Audio Section

MOSFET Amplifier: The Kenwood KDC-BT645U is equipped with a MOSFET amplifier. Compared to conventional power supplies, the MOSFET amplification circuit is smaller and more efficient, and it delivers increased power with less distortion and absolutely zero on/off switching noise. More power means louder and cleaner music at higher volumes because you're not pushing the limits of the amplification circuit. The power output specs for the KDC-BT645U are as follows:

• Full Bandwidth Power: 22 watts RMS x 4 channels (at 4 ohms, 20-20kHz, 1% THD)
• Maximum Output Power: 50 watts x 4 channels

Rotary Volume Control: The CD receiver uses a 3-way rotary volume control that increases and decreases the volume of the stereo from 0 to 35. The rotary knob also controls other audio settings such as Balance, Fader, Bass, Mid, Treble and preset EQ settings. In addition, the rotary knob allows you to scroll through and select your music tracks when the Music Search function is activated.

Speaker Settings: The Speaker Setting function tailors the System Q Sound Control settings according to the type of speakers in your vehicle. You may select a Speaker Setting of "SP Off" (flat), "SP OEM" (for OEM factory speaker systems), "SP 6x9/6" (for systems with 6" and 6"x9" speakers), or "SP 5/4" (for systems with 4" and 5" speakers).

System Q Sound Control: Eight EQ curves are preset into memory, allowing you to recall the best preset EQ curve for different types of music. Each preset has its own level settings for bass (100Hz), midrange (1kHz), and treble (10kHz). You can choose from the following preset EQ curves - Rock, Pops, Easy, Top 40, Jazz, Natural, User, and Game.

Bass/Treble/Mid Control: The KDC-BT645U also features independent Bass, Treble and Midrange control. You can adjust each one from -8 to +8db. The bass frequency is adjusted at 100 Hz, the treble frequency is adjusted at 10 kHz and the midrange frequency is adjusted at 1 kHz.

Bass Boost: The Kenwood CD receiver also features a Bass Boost control that can be set to the following levels - LV11, LV2 or Off.

Source Tone Memory: This feature allows you to store System Q bass, middle and treble tone settings for each source (CD, Tuner, Aux, and USB).

3-Sets of Preamp Outputs: The KDC-BT645U features front, rear and subwoofer preamp outputs. The front and rear speaker preamp outputs are balance and fade adjustable. The subwoofer preamp output is non-fading. The front, rear and subwoofer preamp outputs are all fixed to the rear chassis of the head unit. The subwoofer preamp output offers the following controls:

• Low Pass Filter: The receiver features a built-in Low Pass Filter control for the preamp-output when the output is set to Sub. You can select from 85Hz, 120Hz, 160Hz or Through (Off).
• Subwoofer Phase: You can also adjust the phase of the subwoofer output between 180-degrees (Reverse) or 0-degrees (Normal).
• Subwoofer Level: Once you have switched the preamp output to "subwoofer" you can independently control the subwoofer preamp output level from the CD receiver. You select levels between -15 to +15.

Volume Offset: The level of each source may be independently adjusted to prevent radical leaps in output volume when switching from one source to another. The available settings range from -8 to 0 (-8 to +8 for Aux source).

Tel Mute: The KDC-BT645U features a cell-phone mute wire (brown) in its harness that when hooked up to your car's phone system mute wire will automatically mute the receiver's audio signal when a call comes in.

Key Beep: The in-dash head unit provides an audible beep to confirm button operation. This function can be turned On or Off.

Radio Functions

AM/FM Tuner: The Kenwood KDC-BT645U features a built-in AM/FM tuner. You can choose one of three tuning modes: Auto 1 (seek tuning), Auto 2 (cycles through and tunes the selected band's preset stations only with each button press), or Manual.

Tuner Presets: The KDC-BT645U's tuner features 3 FM banks (1, 2, 3) and 1 AM bank for storing presets. The Kenwood KDC-BT645U offers two preset modes:

• Normal: You can store 6 presets for each AM/FM bank giving you a total of 18 FM presets and 6 AM presets.
• Mix: You can store a mixture of 6 AM/FM presets for each AM/FM bank giving you a total of 24 AM/FM presets of any mixture.

Auto Memory Tuning: Not only does the CD receiver's tuner allow you manually enter your desired presets you can choose to have the unit automatically put stations with good reception in the memory banks automatically; this is a handy feature when traveling.

Direct Tuning: You can tune in a desired AM/FM radio station directly by entering the frequency number using the included remote control.

Mono Mode: This feature reduces the noise (static) when a stereo broadcast is received as monaural (for FM band only).

Satellite Radio Ready: There are several options for connecting an optional XM or SIRIUS Satellite Radio receiver to this receiver:

• SIRIUS Satellite Radio: To receive SIRIUS Satellite Radio, you can connect the optional SIRIUS Universal Vehicle Tuner (607SCC1) and the optional Kenwood Sirius Satellite Radio Interface (113KCASR50); package item number 700SIRKENW, or you can connect the optional KCA-SR50 Kenwood Sirius Satellite Radio Interface and the SiriusConnect vehicle docking kit (607SCVDOC1); package item number 700SIRPKEN, along with your compatible SIRIUS Dock & Play receiver.
• XM Satellite Radio: To receive XM Satellite Radio connect the optional CNP2000UCA XM Tuner and the Kenwood CNPKEN1 adapter cable (700XMKEN2, sold separately).

HD Radio Ready (with iTunes Tagging): With an optional Kenwood HD Radio tuner (113HR300, sold separately), you will be able to receive digital AM/FM broadcasts from local stations where available. This new technology will significantly improve audio quality and reception, as well as include information such as artist name and song titles or traffic news, viewable on the receiver's display. The Kenwood KTC-HR300 HD Radio tuner is also capable of iTunes tagging. iTunes tagging gives you the ability to tag a song (up to 50) and stores it to a connected iPod. The next time your iPod is connected to iTunes, the tagged songs are displayed with the option to purchase them from the iTunes Store.

Disc Playback

MP3/WMA/AAC Playback: The KDC-BT645U can play MP3 (8-320 kbps), WMA (32-192 kbps), and AAC (8-320 kbps) files recorded on CD-ROM, CD-R, and CD-RW discs in ISO9660 Level 1/Level 2, Joliet, Romeo, and Long file name formats. Each disc should have a maximum of 8 directory levels, 50 folders, and 255 files per folder with a maximum of 512 files and folders. During MP3/WMA/AAC playback, the unit displays recorded ID3 Tag (Ver.1/2.2/2.3/2.4) information. The head unit will display up to 60 characters.

Supreme Setting: When MP3 or WMA files encoded at a low bit rate (less than 96 kbps, 44.1k, 48kHz) are played, the Supreme Setting function restores their high frequencies so the sound quality is closer to files encoded at a high bit rate. The processing is optimized for the compression format and the bit rate used. When the Supreme Setting is Off, the unit plays the original sound stored in the audio file.

Text Scroll: The KDC-BT645U will display CD text or Audio file text. You can set the text scrolling feature to two different modes (Auto or Manual) to scroll longer titles across the screen.

Music Search: The Kenwood AM/FM CD receiver features a Music Search feature which allows you to scroll through and select your MP3/WMA/AAC music folders and files, as well as scroll through your audio CD's music tracks using the head unit's rotary knob.

Direct Music Search: The supplied IR wireless remote control (RC-405) allows you to search for music directly by entering the track number.

Last Position Memory: If the unit is shut off or switched to the tuner mode while a CD is playing, the next time CD is selected as the source, playback will resume from the point where it left off.

CD Read: This function sets the method for reading a CD disc. You can choose between two modes:

• CD1: Automatically distinguishes between audio file disc and music CD when playing a CD, CD-R/RW disc.
• CD2: When unable to play a special formatted CD, set this function to CD2 to force playing. Some music CD discs may be unplayable even when set to this mode.

Off Eject: The KDC-BT645U allows you to eject your disc for 10 minutes after switching off the vehicles engine.

Aux/USB/iPod Connection

USB Port: The Kenwood KDC-BT645U features a front panel Full-Speed (Max. 12Mbps) 2.0 USB type-A port that is hidden behind a sliding cover. The USB port enables connection and control of a portable USB mass-storage class device with MP3 (8-320 kbps), WMA (32-192 kbps), and AAC (8-320 kbps) music files. The USB port is compatible with all USB mass storage class devices that support the FAT16 or FAT32 file system. Your USB device should only have a maximum of 8 directory levels, 255 folders, and 255 files per folder with a maximum of 65,025 files and folders. During MP3/WMA/AAC playback, the unit displays recorded ID3 Tag (Ver.1/2.2/2.3/2.4) information. The head unit will display up to 60 characters. When your USB device is connected to this unit, it can be charged up provided that the KDC-BT645U is powered on.

iPod Direct: The KDC-BT645U's front-panel USB port also acts as an iPod/iPhone high-speed direct connection when used with the optional Kenwood USB Direct Connection Cable (113iP101, sold separately) or the USB/iPod cable that comes with your iPod/iPhone. Using either cable allows audio playback, music navigation, information display, and charging of select iPod/iPhone models from the KDC-BT645U.

• USB Connection: The USB connection allows your iPod's large music libraries to be loaded instantly to the headunit and sound quality to be maximized through the headunit's 24-bit D/A converter, allowing for a Signal to Noise ratio up to 105dB.
• Audio Playback: The Kenwood headunit supports audio playback of music files and podcasts stored on your iPod or iPhone.
• Music Navigation: When your iPod/iPhone is connected to the KDC-BT645U, you can choose to operate your iPod/iPhone via the Kenwood headunit's controls or your iPod/iPhone's clickwheel or touchscreen.  If you select to control your iPod/iPhone from the KDC-BT645U, the Kenwood headunit will allow you to navigate your iPod's music by Playlist, Artists, Album, Genre, Composer, Song, or Podcast (your iPod's click-wheel/touch-screen will be locked in this mode). You can search these categories alphabetically or using a percentage search (0.5%, 1%, 5%, 10%). You can also browse for music of the same artist or genre as the one being currently played (Related Search). In addition, you can create your own custom iPod playlist (up to 10 songs) from the headunit.
• Information Display: The KDC-BT645U will also display your iPod/iPhone's music file information when you are controlling your iPod or iPhone from the Kenwood headunit. If you choose to operate your connected iPod/iPhone via its clickwheel or touchscreen controls, the KDC-BT645U will not display your iPod's music information (the headunit will instead display iPod MODE).
• Charging: While connected and the ignition switch is set to ACC or ON, the headunit's USB connection will power and charge your iPod/iPhone.

iPod/iPhone Compatibility Chart: The Kenwood KDC-BT645U is "Made for iPod/iPhone" compatible and supports the following iPod/iPhone model features (as of Feb. 2010):

AUX Input: The KDC-BT645U is equipped with a front panel 3.5mm mini-jack auxiliary input for connecting external portable audio devices such as an MP3 player. The KDC-BT645U allows you to select the source type displayed when using the auxiliary input. You can choose from AUX, DVD, Portable, Game, Video or TV.

Rear Auxiliary Input "Ready": The unit already features a front panel auxiliary input, but if you need a second auxiliary input, one can be added to the rear of the unit. When used with an optional adapter, this unit can accept a rear input from an auxiliary source. When the CA-C1AUX adapter (113CAC1AX, sold separately) is used, you cannot connect a CD changer to the head unit because the adapter plugs into the DIN changer control connection on the head unit. When the KCA-S220A 2-changer switch (113KCAS220, sold separately) is used, you can connect a CD changer and an auxiliary audio source at the same time. When an auxiliary audio source is connected, you can choose from one of six names for the source: AUX, DVD, Portable, Game, Video or TV.

Bluetooth/Remote Control

Built-In Bluetooth: The Kenwood KDC-BT645U CD-Receiver features built-in 2.4GHz Bluetooth technology (version 2.0) with a range of 32.8 ft and supports the following profiles: HFP (Hands Free Profile), HSP (Headset Profile), OPP (Object Push Profile), PBAP (Phonebook Access Profile), SPP (Serial Port Profile), and SYNC (Synchronization Profile). The controls of the KDC-BT645U can be used to dial a number, answer an in-coming call or end a call. The KDC-BT645U can even be setup to automatically answer a call. The unit also features an integrated microphone with adjustable gain on its front panel so you can carry on your side of the conversation while listening to the caller through your car's front speakers. During a conversation, you can switch between the Private Mode (talking directly on your cell phone) and the Hands Free Mode. Your cell phone must be paired with the KDC-BT645U before you make and receive calls. You can register up to five cell phones (only one paired phone can be used at a time). You can also wirelessly download the short message (SMS) arrived at your cell-phone so that is can be read on the head unit's display. Using the KDC-BT645U, you can dial a phone number in one of the following ways:

• Entering a Phone Number: Allows you to directly dial a phone number up to 25digits.
• Speed (Preset) Dialing: Allows you to register up to 6 phone numbers for quick dialing.
• Phone Book: You can dial by using the downloaded phone book. You can download phone book data from your cell phone to the KDC-BT645U. Up to 1000 numbers can be stored for each registered cell phone. Each number can be up to 32 digits long and each name can be up to 50 characters long. You can search for a number by the initials, or you can search the phone book in alphabetical order.
• Call Log: The Call Log is a list of calls that have originated from and were received by this unit that you can dial. You can select Outgoing, Incoming, or Missed calls.
  • Outgoing Call List: Allows you to dial by using the outgoing call list. Up to 10 phone numbers are stored in the outgoing call list.
  • Incoming Call List: Allows you to dial by using the incoming call list. Up to 10 phone numbers are stored in the incoming call list.
  • Missed Call List: Allows you to dial by using the missed call list. Up to 10 phone numbers are stored in the missed call list.
• Voice Dialing: If your phone supports voice recognition, then you can dial out by voice command. You can register up to 35 voice tags (audio sound is not output during voice recognition).
• Call Waiting: You can answer another incoming call with the current call suspended.

IR Remote Control: The KDC-BT645U comes with the RC-405 IR wireless remote control with a full numeric keypad (0-9). The remote will control Audio, CD, Tuner, Bluetooth, and external device functions. The remote control allows direct access of your music tracks and discs loaded in a connected CD-changer (sold separately), as well as direct access to AM/FM radio stations. It is powered by a single CR2025 3V lithium-cell battery (supplied).

Steering Wheel Remote Compatibility: The unit also features an OEM steering wheel remote control input on the rear of the unit that lets you keep your vehicle's factory radio steering wheel remote controls when used with the optional PAC SWI-JACK Steering Wheel Control Interface Adapter (127SWIJACK, sold separately); or the optional Metra ASWC Steering Wheel Control Interface Adapter (120ASWC, sold separately).

Optional Software

Music Editor Compatible: The Kenwood KDC-BT645U supports the PC application, Kenwood Music Editor Lite (ver.l.0 or later). Kenwood Music Editor Lite is a desktop software that helps organize, manage and transfer AAC, MP3, and WMA music files to your USB devices from your PC. When you playback audio files that have been stored on your USB device using Kenwood Music Editor Lite (ver.l.0) through this unit, you can search a file by title, album, or artist name using the head unit's Music Search function.