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Home >> Volvo >> 1998 >> C70 L5-2.3L Turbo VIN 53 B5234T3 >> Repair and Diagnosis >> Accessories and Optional Equipment >> Radio, Stereo, and Compact Disc >> Description and Operation >> Audio System >> Audio System

Audio System






Audio system





System overview, components
The components included in the audio system depend on the market and equipment level selected.
1. Radio
2. Dolby unit
3. CD player for 6 CDs
4. Booster (amplifier)
5. Power antenna
6. Bass loudspeakers
7. Treble loudspeakers
8. Mid-range loudspeakers
9. Bass loudspeakers
10. Center loudspeaker
11. Treble loudspeakers
12. Splitting filter (for door-mounted loudspeakers)
13. Sub-antenna in bumper.
14. Antenna amplifier (for sub-antenna)






Wiring
The audio system wiring is pre-routed for all components and is integrated into the car's ordinary cable harnesses.

Radios
There are two "large-fronted" radio variants available:
- with a single CD player (SC- 805, 816 or 836 depending on market).
- with a CD player with a magazine for 3 CDs (SC- 900 or 930 depending on market).

Booster (amplifier)
The amplifier is located in a bracket in the cargo compartment.
There are two types of amplifier:
- 4x60 Watt (adapted for the SC-8XX).
- 4x100 Watt (adapted for the SC-9XX).

Antennae
As standard the C70 has two antenna, a main antenna (power antenna) and a sub-antenna. The sub-antenna is mounted in the rear bumper on the right-hand side and has an antenna amplifier mounted in the cargo compartment under the right tail lamp.
On cars with RTI the sub-antenna is used by the TMC/FM receiver for RTI.
On cars without RTI and with a SC-8XX radio the sub-antenna ha no function.
On cars without RTI and with a SC-9XX radio both antenna are connected to the radio.
The SC-9XX has the Diversity system (dual antenna system).
The radio waves received by the radio pass through a multipath detector which reduces the signal to an intermediate frequency. The detector detects whether there is interference with the signal. When the main antenna (power antenna) provides poor reception (interference) the detector transmits a control signal to a switch so that the radio connects to the sub-antenna. This technology allows the radio to deal with multipath interference better.

Loudspeakers
1" treble loudspeakers in the dashboard.
8"bass speakers and 4" mid-range loudspeakers in the doors.
A separate splitting filter, mounted in the door, splits the signals between the loudspeakers. 8"bass speakers and 1" treble loudspeaker in the parcel shelf.

Center loudspeaker and Dolby unit (Dolby ProLogic Surround Sound system)
Only the SC-9XX is ready for this system.

Note! Cannot be combined with RTI.

The center loudspeaker consists of a 4" bass speakers and a 1" treble loudspeaker.
The Dolby unit splits the normal stereo sound into several channels.

CD player for 6 CDs
Standard/option/accessory depending on market.
The CD player is mounted in the cargo compartment on the same bracket as the amplifier.





SC-900/930
Large-fronted radio with large ergonomic buttons for easy and safe operation.
Requires an external amplifier, there is only an amplifier for the center loudspeaker (25W) in the radio.
The SC-930 is used in Japan (it does not have RDS, traffic information in Japan uses 2 Separate AM frequencies).
The SC-900 is used in other markets.

Dolby ProLogic Surround Sound

Function
- The car must have a center loudspeaker and Dolby unit.
- The system only works with the cassette player or CD player (not with the radio).
- The Dolby unit divides the normal stereo channels from left - right to left - center - right.
In addition, ambient surround sound is produced by the rear loudspeakers. This ambient surround sound mirrors the resonance in the recording studio.
Most recordings today are made so that the vocalist/soloist is heard from straight ahead while the orchestra is heard over the entire left-right panorama and from behind.
Dolby ProLogic Surround Sound recreates a sound that is close to reality (the recording situation).

Operating the system
- Press the "MODE button" to select function. The selected function is shown in the display.
Dolby ProLogic 3 CH = center loudspeaker connected but without surround sound.
Dolby ProLogic 5 CH = center loudspeaker connected with surround sound.
- The ambient surround sound volume from the rear loudspeakers can be controlled with the "BASS" button in its outer position.
- The volume of the center loudspeaker can be controlled with the "FADER" button in its outer position.

Summary of SC-9XX functions
- Diversity-system (dual antenna system).
- RDS with EON.
- Radio text, information about program content.
Only transmitted by certain stations.
- Traffic information and alarm.
Traffic information from a certain station can be prioritized.
The alarm function can be enabled/disabled.

Programmable PTY and News button
- Preset buttons (1-6) are programmed for certain types of program (reprogrammable).
The display language can be changed (Swedish, French, German, English).
- Electronic volume control.
- Automatic volume setting when receiving traffic information, news and PTY priority.
- Balance control, front - rear (fader).
- Balance control, right - left.
- Separate bass and treble controls.
- Automatic loudness.
- Automatic mono/stereo switch.
- Connector for center loudspeaker and Dolby unit.
- Telephone mute.
- ASC - automatic volume setting depending on vehicle speed.
This function can be enabled/disabled.

Setting the internal equalizer (with or without parcel shelf loudspeakers)
- This is normally set by the factory or dealer.
- 3 FM bands, 1 AM band (MV + LV).
- Station search up/down and scan function.
- Manual station preset.
3x6 FM, 6 AM.
- Autostore - automatic station preset.
10 FM, 10 AM.
- AF - automatic search for alternative frequencies.
This function can be enabled/disabled.

Frequency step setting when searching for stations (market setting)
- This is normally set by the factory or dealer.
- Prepared for remote control.
- Full logic cassette player with auto-reverse, fast forward/reverse, search for next (NXT) track and repeat (RPT), Pinch-off, Dolby B, automatic setting depending on the type of cassette tape being played, pause function.
- Built-in 3 disc CD player with music search, play time display, disc and track select, random function, pause function.
- Functions for controlling a separate CD player.
- Low level output for an external amplifier.
- Factory programmed anti-theft code.

Note! Special care should be taken with the functions marked in bold when replacing the radio.

- Diversity system. There is a dual antenna symbol on the left of the display which lights when the diversity system is enabled. When there is a sub-antenna amplifier fault this symbol goes out.
- When the preset button 6 is held down and with the radio on, the text "subantenna OK" or "NO subantenna" is displayed.
- Holding down preset button 3 and turning on the radio displays all text and symbols in the display.

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