System Description: Overview
The audio unit acts as the "processor" for all audio functions. You can select of the audio functions from the front panel, the audio remote (on steering wheel), or by using the navigation voice control system. The audio display provides the current front and rear audio status. For vehicles with the navigation option, additional audio information is available by touching the audio button. (See owner's manual for more details.)
Each audio component passes its audio signal to the audio unit. In addition, it communicates with the audio unit via the GA-Net bus. Any open connection in this circuit will cause audio and navigation functions to appear inoperative.
With the premium sound system, an audio amplifier unit powers the speakers, otherwise the speakers are powered directly by the audio unit.
The system includes an active noise control system to cancel some of the vehicle noise. It use a sine-wave-shaped sound output to cancel low frequency noise. Two microphones detect the low frequency sound, and the system outputs a canceling sound through the audio speakers.
The 6CD changer output can be directed to the audio unit.
The XM radio plays through the audio unit.
A security signal is daisy-chained between the audio and navigation components for integration into the vehicle's alarm system.
The optional navigation system provides voice control for front/rear audio, XM, and CD player. Voice control commands are communicated on the GA-Net (audio unit). When using the TALK/BACK or route guidance (RG), only the center speaker is muted and the front speakers give the navigation instructions. When using OnStar/HFL/AcuraLink, the center speaker, the rear speakers, and the subwoofer are muted and the front speakers give the telephone sound. When using OnStar/HFL/AcuraLink and RG or TALK/BACK, the center speaker, the rear speakers, and the subwoofer are muted and the front speakers give the telephone sound and the navigation instructions. Muting commands are passed on the GA-Net bus. For more information, see NAVIGATION SYSTEM article . The outline of the audio interruption function is shown in the following table.
| Contents | Audio output | |||||
|---|---|---|---|---|---|---|
| Center CH | Left front CH | Right front CH | Right rear CH | Left rear CH | Subwoofer CH | |
| TALK/BACK | MUTE | Navigation sound | Navigation sound | Audio | Audio | Audio |
| Route guidance | MUTE | Navigation sound | Navigation sound | Audio | Audio | Audio |
| OnStar/HFL/AcuraLink | MUTE | Telephone sound | Telephone sound | MUTE | MUTE | MUTE |
| OnStar/HFL/AcuraLink and RG or TALK/BACK | MUTE | Telephone sound and navigation sound | Telephone sound and navigation sound | MUTE | MUTE | MUTE |
System Diagram
| Item | Definition |
|---|---|
| Active Noise Control | The active noise control system cancels some of the vehicle noise. This occurs in the 1,500-2,400 RPM range. Microphones detect the low frequency sound, and the system outputs a canceling sound from the audio speaker. |
| AM (Amplitude Modulation) | The type of transmission used in the standard radio broadcast band from 530 to 1710 kHz. |
| Amplifier | A device that increases the level of a signal by increasing the current or voltage. |
| Antenna | A device used to send or receive electromagnetic waves through the air. |
| ATA (PC card) | A type of card that has been tested for use in playing WMA, and MP3 music files in the PC card slot. Sizes of up to 1 GB have been tested. |
| Auxiliary jack | Allows the client to use a portable audio device to input music recordings. |
| Balance | A control that changes the relative volume of the left and right channels. |
| Band | A range of frequencies between two definite limits. Bands are assigned by the Federal Communications Commission for specific uses. |
| Bass | An adjustment for the low frequency sounds of around 160 Hz and below. |
| Byte | A unit of storage for computer files and memory. A CD holds approximately 700 million bytes. |
| Cassette | Audio or video magnetic tape container having two reels. Clients can insert it for recording or play back. |
| Compact Flash | A standard for small-size (3x4 cm), memory cards used in mobile computers, PDAs, digital cameras. Compact flash memory cards are available in size of 32 Mb up to 4 GB or more and can be played in the audio PC slot. Sizes above 1 GB has not been tested. |
| CD (Compact Disc) | A 4.5-inch plastic disc containing digital audio recording that is played optically on a laser equipped player. Never use discs with a paper label. In a hot car, labels can curl up and jam the unit. |
| CD (audio disc) Changer | CD player that can store and play more than one CD. Two types are available. Some units accept CDs fed into the changer one at a time, and others accept a magazine (with CD's stacked in a container). |
| CD player | A component designed to play compact disc CD recording using a laser optical pickup. The signal from a CD player usually requires amplification. |
| Distortion | Inexact reproduction of an audio signal caused by playing music at levels the audio system cannot handle. |
| Dolby (noise reduction) | A processing system developed by Dolby Laboratories that reduces the background noise on recording media. The result is a clearer playback from the audio system. |
| DVD (Digital Versatile Disc) | A 4.5-inch CD-like format used for storing movies with digital audio and video features. The DVD-A format is a DVD format designed for DVD audio systems. Some vehicles can play DVD and DVD-A formats. |
| Equalizer | A device that changes the relative volume of individual frequency bands to suit personal tastes of the listener. |
| Fader | The control that adjusts the relative volume levels of front and rear speakers in a four-speaker system. |
| Format | To prepare a PC card to receive files. This function is performed on a PC. Always choose either FAT or FAT32 as the format type-NTSF format is not accepted by the system. Pick the default sectors for the format method selected. |
| FM (Frequency Modulation) | The form of modulation used for radio and television sound transmission in most of the world. Less prone to interference than AM. The FM broad cast band covers roughly 87 to 108 MHz. |
| GB (Gigabyte) | A unit of memory or disk storage equal to one billion bytes (1000 million bytes). |
Audio Glossary
| Item | Definition |
|---|---|
| HDD | Abbreviation for hard disc drive. They are sensitive to heat and it is not recommended that they be used in the PC card slot for playing audio files. |
| Hertz (HZ) | The unit of frequency equal to one cycle per second (CPS). One kilohertz (kHz) equals 1,000 CPS; one megahertz (MHz) equals 1 million CPS. |
| Integrated Amplifier | A component that combines a pre amp and a power amp into a single unit. A receiver combines an integrated amp and a tuner into a single unit. |
| Jewel Case | The hard plastic case that contains a compact disc or DVD. Always use a jewel case to prevent scratches on the underside of a CD or DVD. |
| LCD (Liquid Crystal Display) | A type of digital display that changes reflectance or transmittance when an electrical field is applied to it. |
| Memory | Circuitry or devices that hold information in electrical or magnetic form, such as the AM/FM radio presets. |
| MB (Megabyte) | One million bytes. Written as 1 Mb. Megabytes are used as a measure of digital storage space. For example, a CD can hold 650 Mb. |
| Mic | An abbreviation for microphone. For vehicles with navigation, the microphone accepts navigation voice commands to control audio and navigation functions. |
| MP3 music files | MP3 is an audio coding format. MP3 is a popular audio compression format on the Internet and computers. CDs, and PC cards with these files can be played on some vehicle's audio system. |
| Mute | When the navigation gives guidance, the front speakers are muted (no music). When you use the voice control system, all of the speakers are muted. |
| Noise | Unwanted random sounds like buzzing, hiss, pops, static, whine, etc. |
| PC Card | The slot used for playing MP3 and WMA music files. The PC card is usually a combination of a small flash card in a PCMCIA adaptor that slides into the slot. The ATA, SD, and compact flash types of cards have been tested up to 1 GB. |
| PCMCIA | A computer standard for the slot that the PC card slides into. Another term for the PC card slot. |
| Processor | The part of an audio device that performs tasks/calculations. In the audio unit the processor handles muting to allow the navi to speak voice commands, and the decoding/playback of the sound files etc. |
| Radio | A head unit that combines a tuner, a preamplifier, and often a power-amplifier. |
| Audio Remote switch | The switches on the steering wheel that control the audio system. |
| SCF (Cold Start Fix) screens | These screens are displayed if the system requires a GPS initialization. The vehicle should be moved outside into an open area away from buildings/power lines. |
| Stereo | A recording of at least two channels where you can hear sound or music from the left or right side. |
| SD (Secure Digital) card | This compact type of memory card allows for fast data transfer and has built-in security functions. SD cards have a small write-protection switch on the side. |
| Shield | A metallic foil or braided wire layer surrounding conductors which are designed to prevent electrostatic or electromagnetic interference (noise) from external sources such as buzzing, or popping sounds heard on the speakers. |
| Speaker (Loudspeaker) | A device that converts electrical energy into acoustical energy (sound). |
| Speed-sensitive Volume Compensation (SVC) | The SVC increases the audio volume to compensate for increased interior noise when the vehicle drives at freeway speeds. |
| Sub-woofer | A loudspeaker made to reproduce the lowest audio frequencies, approx 25 Hz to 125 Hz. |
| Track | A sound recording on a CD, tape, or PC card. |
| Treble | An adjustment for the high frequency sounds of around 2.5 kHz to 20 kHz. |
| Tuner | A component (or part of a component) that receives radio signals and selects one broadcast from many. |
| Tweeter | A speaker designed to reproduce the higher frequencies (treble) only. |
| Voice Coil | A coil of wire wrapped around a tube and then attached to the speaker cone or diaphragm. When an audio signal is applied, the coil becomes an electromagnet and interacts with the permanent magnet causing the cone or diaphragm to vibrate. We interpret this vibration as sound. |
| Volume Control | Allows you to control the loudness of the music. |
| WMA music file | Windows Media Audio File. This is an accepted format for music files to be played on either a CD or a PC card. |
| Woofer | A speaker that is designed to reproduce bass frequencies only. |
| XM Radio | Satellite based radio transmission, which also uses a ground based repeater network to ensure seamless reception. The channels originate from XM's broadcast center, in Washington, DC, and uplink to two satellites. These satellites transmit the signal across the entire continental United States. |
| XM Receiver | The external component that receives and processes the XM signals from the XM satellites, and terrestrial (land) stations. The audio unit communicates to the XM receiver over the GA-Net bus. |