Introduction

Display when the radio is receiving an HD Radio broadcast

HD radio is a brand name registered by the Ibiquity digital corporation2. They are the developer of a broadcasting technology called IBOC or In Band On Channel, which refers to the method of transmitting a digital radio broadcast signal centered on the same frequency as the AM or FM station's present frequency.

The IBOC system is referred to as a "hybrid" since it is both analogue and digital. During hybrid operation, receivers still continue to receive the analogue (non-digital) signal. HD radio receivers incorporate both modes of reception, where the receiver will automatically switch to the analogue signal if the digital signal cannot be decoded or is lost by the receiver.

When you have tuned to an HD Radio station, the symbol will appear in the audio system display.

More information about HD radio and IBOC can be found on Ibiquity's website, www.hdradio.com and www.ibiquity.com.

Benefits of digital broadcasting
• Better sound (FM sounds near CD quality and AM as analogue FM).
• Some FM frequencies offer a greater number of listening choices through “multicasting” (consisting of a frequency's main channel and any sub-channels that may also be available on that particular frequency.

See also the section "Sub-channels" below).

• When receiving a digital signal there is no multipath disturbance or hisses/pops/ crackling due to outside influences.

How HD broadcasting works
HD Radio works similarly to conventional radio and broadcasts of this type are available in many areas of the United States. However, there are a few key differences:

• Instead of transmitting one analogue signal, stations send out a bundled signal – both analogue and digital.
• An HD radio receiver can receive both digital and analogue broadcasts. Depending on the terrain and location of the vehicle (which will influence the signal strength), the receiver will determine which signal to receive.

Limitations
• Main channel vs. sub-channels (FM only): The main channel is the only channel that can receive in hybrid mode (both digital and analogue). If a frequency has subchannels, they are broadcast in digital mode only. The main FM channel will be displayed as, for example, 93.9 WNYC (Volvo uses the symbol > to indicate there are sub-channels available) The sub-FM channels will be displayed as 93.9 – 2 WNYC, 93.9 - 3 WNYC, etc.
• Reception coverage area: Due to current IBOC transmitter power limitations, the reception coverage area in digital mode is somewhat more limited than the station's analogue coverage area. Please be aware that as with any radio broadcast technology, terrain, time of day, foliage level and building location can have positive or negative effects on radio reception.
• Analogue to digital/digital to analogue blending: Analogue to digital blending will occur as the signal strength reaches a preset threshold in the receiver. This will be noticeable in fringe areas (areas with weak reception) and is normal.

NOTE
There may be a noticeable difference in sound quality when a change from analogue to digital or digital to analogue occurs, such as:
• Volume increase or decrease
• Equalizer settings, i.e., Bass/ Midrange/ Treble cut or boost
• Time alignment (Digital program material in extreme cases can be as much as 8 seconds behind the analogue). This will noticeable as a "stuttering" effect.
The above items are dependant on the broadcaster's equipment settings and do not indicate a fault in the vehicle's radio receiver or antenna systems.

Switching HD on or off

The factory setting for HD radio is on. However, when driving through areas with weak HD signals (fringe areas), you may experience that the radio repeatedly switches between analogue/ digital and digital/analogue reception. If this happens, it may be desirable to switch HD off.

To do so:

1. Be sure the audio system is switched on and in AM or FM mode.
2. Press MENU in the center console control panel.
3. Press ENTER to turn HD off (the X will disappear from the box on the display screen).

This will disable the radio's capability to receive digital broadcasts but it will continue to function as a conventional (analogue) AM/FM receiver. Please note that when HD is switched off, it will not be possible to tune to sub-channels (see the following section for a more detailed explanation of sub-channels).

Repeat steps 2 and 3 above to reactivate HD (an X will appear in the box on the display screen).

Sub-channels

Example of an HD Radio station with sub-channels

In many cases, a main HD Radio station (FM wavebands only) will also have sub-channels offering additional types of programming or music.

In such cases, a number will be displayed to the right of the frequency number indicating that the currently tuned frequency has at least one sub-channel. The "2" in the illustration indicates that you are currently listening to the first sub-channel on frequency 93.9.

Selecting sub-channels To listen to a station's sub-channel(s), press the right arrow key on the center console or on the steering wheel keypad. To go back to the main channel, press the left arrow key. To go to subchannel 2 (if available), press the right arrow key.

If you are currently tuned to a frequency's main channel, pressing the left arrow key will tune to the next lower radio frequency.

NOTE
• When the radio has gone into HD mode, it may take several seconds before the ">" symbol (if the current frequency has any sub-channels) is displayed to the right of the frequency. Pressing the arrow keys before the number is displayed will cause the radio to tune to the next available radio station, not to the current station's sub-channels.
• When you are no longer in broadcasting range of the currently tuned sub-channel, No HD reception will be displayed.

The radio will then be muted and it will be necessary to tune to or search for a new radio station.

Sub-channels can also be stored as presets, see page 252 for information on storing stations.

If you press a sub-channel's preset button, it may take up to 6 seconds before the channel becomes audible. If you press this button while you are out of digital range of the transmitter, No HD reception will be displayed.