Choosing a Car Stereo

With the huge choice of car audio equipment availableUSB/Memory Card
today it is often difficult to decide what car stereoWith the rapid adoption of MP3 format and the
would best suit your needs. This article will hopefullyavailability of cheap USB memory sticks car audio
help you negotiate the technical minefield and makemanufacturers have started to adopt USB ports on
the best choice for your requirements.their equipment as standard. A USB stick or memory
There are two main contributing factors to the qualitycard can be thought of as a very small CD usually
of the audio that is produced by any audio equipmentabout a couple of inches long and about half an inch
which are the frequency response and signal-to-noisewide but capable of storing vastly more information
ratio (SNR). The frequency response of the ear isthan a conventional CD. Something to check when
around 20Hz to 20KHz although this often diminishesbuying a head unit supporting this feature is the upper
with age. A 'loud' facility is sometimes provide to boostmemory limit of the USB stick or memory card. Typical
the frequencies that become degraded with age. Thememory cards today are around 2-4GB which would
SNR is important as it is what constitutes thestore many albums however these sizes may not be
background hiss that is often associated with cheapersupported by the head unit.
audio equipment.If you purchase a head unit supporting this type of
The car stereo or head unit today can play audio frommedia then you'll need to make sure that you have a
a wide variety of sources which we will now discussmethod of getting the music from you CD collection
below.onto the memory stick. This will involve 'ripping' the
Cassette Deckaudio and copying it onto the memory. There are
If the reason for replacing your car stereo is to allowmany programs available for doing this such as
you to play your CD's or music from your iPod thenWindows Media Player.
please be aware that it is possible to purchaseRadio
equipment that allows you to play music from anMost people are familiar with car radio's and
external source. These specialised adapters look like aunderstand what to look for when purchasing one.
cassette with a flying lead that plugs into your alternateHowever something to keep in mind when looking is
music source ie iPod, CD player etc. This is often athe uptake of DAB radio which is the new digital
very cheap and easy alternative if funds are tight!transmission method.
Audio Cassettes in general do not give as good anDAB radio uses modern digital compression techniques
audio experience as CD players as their frequencyto offer a greater variety of music and programmes
response and SNR is often inferior to that of modernas well as short messages etc that often appear of
digital equipment.the display. Since this is a new format and isn't widely
Although cassette tape sales have declinedadopted as the mainstream format most DAB radios
extensively it is still possible to purchase due to thealso still support FM transmissions.
amount of tapes that are still out there however as aThe DIN form factor
long term investment a CD or MP3 player wouldFinally something which should be overlooked is the
probably be a better choice.form factor and connections for the head-unit. With
CD playerearly cars there wasn't really a standard which led to
The CD has been around for many years now and isall sorts of problems when replacing the factor
well established in the market-place. A CD can storestandard unit. However there is now a standard size
its information in a multitude of formats but the mostreferred to as the DIN which is 2 1/8" (50mm) tall and 7
popular at the moment is usually just referred to as an1/8" (180mm) wide and double-DIN which is twice as tall
Audio CD in the specifications. These are the CD'sas the standard DIN size.
that you can buy of the shelf from any major musicThe connectors used to plug the stereo in are fairly
retail shop.common but there is no one standard connector.
As with all technology the the common audio format isLuckily due to the size of the problem there are many
under threat by a relatively new format referred to asdifferent types of adaptor readily available in most car
MP3. MP3 is a digital audio compression technique thataudio shops.
allows much more audio to be squeezed onto a singleOne problem often experience with fitting new audio
CD. A typical compressed song will be roughly 4-6MBequipment is with the memory 'forgetting' its settings.
depending upon the quality of the audio and a typicalThis is often due to the power supply wires to the
CD can store around 700MB of data. So you can seehead unit being switched over. To over come this
that you can store many more songs using MP3problem the manufacturers of the cabling adapters
technology than with the conventional music CD's.easily enable the yellow and red wire to be
It is also possible to purchase a head unit that has ainterchanged which will fix the problem.
remote CD player or CD changer. A CD changer isIt is always worth checking out many retailers before
like a mini duke box that can be located in your boot,making a selection on a head unit and I would
glove compartment etc. They typically have betweenrecommend searching an automotive directory for the
6 and 12 CD's within them and often support the abilitybest choice.
to play songs randomly between all the CD's.