Car Audio Explained
RADIO - AM/FMRadio receivers work by picking up a signal transmitted by electromagnetic waves. The information is carried by modulating properties in these waves. When radio waves pass an electrical conductor they create an alternating current, this can then be detected & transformed in to sound using both AM & FM radio waves.
Receivers are usually attached to an external aerial that helps to pick up the clearest signal & not loose quality in the sound transmitted. |
IN CAR DIGITAL RADIO - DABThe term Digital Radio refers to radio transmissions that are sent in digital form instead of analogue (AM & FM).
Digital Audio Broardcasts (DAB) do not suffer from interference associated with analogue radio such as hissing & crackling & therefore provide better reception & sound quality. DAB allows the user to scroll through available stations & select them directly instead of 'station searching' the traditional way. DAB supports scrolling data, this means you can see the DJ, the artist, track or show on the screen of a DAB compatible Head Unit. DAB has actually been around for about 20 years though the technology has been slow to take off. Constant developments are being made to improve Digital Radio. The latest being DAB+ which is thought to be twice as efficient & adopts the AAC audio codec. Unfortunately DAB is not forward compatible so a DAB-only receiver will not be able to pick up DAB+ broadcasts through newer receivers will be compatible with DAB, DAB+ & DMB. The UK has NO plans to switch to DAB+ or any other type of digital broadcast at the moment. |
RDS - RADIO DATA SYSTEMRDS or Radio Data System is a standard for sending small amounts of digital information using conventional FM broadcasts. RDS is used in car radios to show the station name & receive Travel Announcements (TA) and/or Traffic Programs (TP). These announcements can intercept what is playing through the Head Unit at the time (radio,CD,Digital etc).
RDS is usually a feature on all modern Head Units. |
MECHLESS STEREOMechless devices are the latest major change in Head Unit production, they are designed specifically for use with external storage devices (ipods/iphones/MP3 Players/SD Cards etc) & do not have a CD drive. By loosing the CD mechanism manufacturers can produce head units with larger more efficient displays making it easier to scroll through folders or libraries of music. Some also have a display capable of playing video from the storage devices. This design of aftermarket Stereo is becoming ever popular as a lot of us carry our entire music library on our Smartphones or external device.
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