Audio Jargon Buster
Auto Store/Auto Tuning:
At the touch of a button the radio will search for the radio stations with the strongest reception and will automatically save them for you
Balance
Found on your head unit the balance control allows you to move the sound to the left hand or the right hand side of the car. This is useful for improving the stereo effect from the speakers.
Bandpass enclosure
A bandpass bass enclosure is the most complex design there is, it consists of at least two chambers and at least one of those will be vented, it is also the most difficult to design and construct as the woofer is mounted inside the cabinet. The woofer is mounted in a rear enclosure which can be sealed or ported which plays into the front vented chamber. Bandpass enclosures are Capable of the highest output of all enclosure types, up to 3 times louder than the same woofer in a sealed box
Bass
The lowest part of the audio frequency spectrum. Bass is what you can feel shake your car and punch your chest. A system with excellent bass is always going to get plenty of attention.
Bridging
Many amplifiers offer you the opportunity to "bridge" their channels which basically means combining 2 stereo channels together to produce the full output of both channels into a single mono channel. Normally this will be done to supply a subwoofer with more power. However be careful when bridging as you will need to make sure you get the impedance (see Ohms) correct other wise you may damage the amplifier!
CD-R/RW Playback
Some CD head units can have problems playing the CD´s you made on your computer. However, if you see the term CD-R/RW Playback it means that you should have no problems at all.
CD Text
Some CD´s come with certain information such as track names stored onto the disc. If you have a CD player with CD Text it means that it will be able to display this information.
Coaxial
A coaxial speaker is one which incorporates two speakers (usually a woofer and a tweeter) into the same unit. You will normally find the tweeter mounted in the centre of the speaker with the larger woofer behind it.
Components
Component speakers are ones where the woofer and tweeter are completely separate and come with an external crossover. Because the two are separate it allows you to fit them into different positions so that you get the best sound.
Crossover
A crossover takes the original signal and separates it into the specific frequencies for each of the speakers Bass to the subwoofer, midrange to the woofer and high frequencies to the tweeters. There are 2 types of crossover, passive and active. Passive crossovers are fitted in line between the amplifier and the speakers, they consist of coils and capacitors and split the sound at fixed frequencies. Active crossovers are either an external device fitted between the head unit and the amplifiers or included onboard the amplifier itself. Active crossovers allow adjustment of the crossover frequency which allow you to change the frequencies sent to each speaker allows you to tailor the sound to your preference.
DIN-E
DIN-E is the universal size for an aftermarket head unit. You may find that your car has a larger or strange shaped CD player fitted direct from the factory and if so you will need an adaptor plate to fit any DIN sized stereo these are very inexpensive.
Face Off
A CD player which has a "Face Off" function means that you can remove the front panel from the stereo when you are not in the car. This makes it less likely that someone will try to steal the CD player as the unit is no use without the face.
Frequency Response
The part of the full audio spectrum produced by the speaker. A subwoofer is designed only to make low frequencies so it will not be able to produce treble for example.
Head Unit
The head unit is the source and heart of the system, usually a CD/Tuner or Cassette/Tuner. The head unit is where you control the volume, fader, balance and more depending on the spec. of the unit.
LCD
LCD stands for Liquid Crystal Display and is the type of screen commonly used on the front of in car head units.
Loudness
Most head units will have a "Loudness" function where at the touch of a button the bass and treble frequencies will be given a boost. This can help compensate for road noise if used correctly.
MP3
The digital file format which is taking over the world! MP3 files allow music to be compressed into very small files which means you can store hundreds of songs on a disc instead of ten or twenty.
Ohms
Ohms is a measure of resistance or impedance. Substances conduct or resist electricity on a scale. Rubber isn't very conducive, copper is. This is why some premium cable are made out of silver and such - these substances conduct electricity better than others. In car audio terms the voice coil (see voice coil) of the speaker is generally made from copper and will have an impedance of 4 ohms. When the electricity passes into the speaker, some of it is 'resisted.' The ohms rating of the speaker is how much is resisted, and an indication of how much energy it takes to drive it - the higher the ohms rating, the more difficult it is to drive. , Some subwoofers have dual voice coils which can be connected in series or parallel to increase or decrease the impedance shown at the amplifier
Peak Power
The peak power is the very maximum that either a speaker can handle or an amplifier can produce. Every manufacturer will calculate Peak power differently so it is difficult to fairly compare products from one manufacturer to another so it is better to look at the RMS (see RMS) power to get a real indication of what they can handle/produce.
Pre-outs
Pre-outs or pre-amplifier outputs are a low voltage connection on the back of the head unit which allow you to connect it directly to an external amplifier rather than using the low powered internal one. The method for connection is an RCA Phono. The more pre-outs a head unit has the better as it is much more flexible allowing you to run separate channels for the front and rear speakers as well as the subwoofer.
Presets
Presets are your automatically stored radio station. For example Radio 1 may be preset to number 1 so all you need to do is press the number 1 button and Radio 1 will automatically be tuned in.
RCA
RCA or Phono cables are used to carry the low level audio signal from the head unit to the amplifier.
RDS
Radio Data System. Radio stations also transmit information along with the music, this can be the name of the station, the type of music the station plays or traffic updates. Head units with RDS allow you to set it up so it will automatically switch to a traffic report on a station even if you are listening to another one at the time.
RMS Power
The Root Mean Square power rating is the best way to measure the power handling capacity of a speaker or the amount of power than an amplifier can produce. In the case of an amplifier to produce a complete unclipped sine wave, the amplitude of first half of the sine wave is measured to give the RMS wattage. In the case of a speaker the RMS power figure relates to the size or amplitude of a sine wave that the voice coil can handle without going into meltdown
Subwoofer
The largest of all the speakers and the one which produces the much loved bass frequencies. Subwoofers will usually be 10, 12 or 15 inches in diameter however they can sometimes be smaller or bigger.
Tweeter
Tweeters are the smallest of all the speakers you will find in your car and they are used to produce the treble, or high end frequencies.
Voice Coil
A voice coil is the coil of wire attached to the apex of the moving cone of a loudspeaker. It provides the motive force to the cone by the reaction of a magnetic field to the current passing through it. By driving a current through the voice coil, a magnetic field is produced. This magnetic field causes the voice coil to react to the magnetic field from a permanent magnet fixed to the speaker's frame, thereby moving the cone of the speaker. By applying an audio waveform to the voice coil, the cone will reproduce the sound pressure waves, corresponding to the original voice, music, etc