CD Players

Build quality:

Some head unit is weak and fragile. Some are built to last. Usually the best way to solve the weight of the device. Also, to see if something is not "fit", or if there are parts that are cheap or poor. The truth is: The larger units tend to be better name. Furthermore, it is more expensive units tend to be better. It is not always a great thing for everyone, but I think the build quality is very important.

Basically the main unit features:

CanOutput:

Most head units built-in amplifier. These drive the speakers. Some head units have internal amplifiers, and therefore requires the use of an external amplifier. Head unit without amps are usually high-end models. In any case, the capacity is measured in watts. We'll talk later watts, but for now, little more than a watt see more volume. Head unit for the majority (unfortunately) are deceptive on power. Usually the specifications on a power unit, said: "50Wx4 MAX output". This meansthat when the laws of physics are at his side, is a clear day across the world, the planets aligned, the bass hits low and hard, and about a tenth of a second, yes, the head unit in 50Wx4. But most of the time, the head unit is probably one quarter of that. Not that the drive manufacturer of the head, it's just that they blew up the truth, and most people do not know better. Yes, of course, many people put a lot of interestin a head-unit production. I am not, because head unit amps suck, and no serious person car audio amp using the main unit is in any case. Head unit Most of the approximately the same effect anyway. 9 times out of 10, an aftermarket head unit will give more power than the factory head unit, and as such will sound better.

RCA PREOUT:

It is used to connect external amplifiers to your unit head. This is the same red and white cables that you use for the home system. Basic positionPREOUT devices usually have a set (front left, front right). Some head units have two set (front left, front right, rear left, rear right), but most decent head units are 3 set (front left, front right, rear left, rear right, subwoofer left, subwoofer, a right). A word report on the subwoofer outputs: Sometimes they are called "non-fading" outputs because they are influenced by the head unit fade control (front to back balance). If you are not planning an external amplifier, it isDo not worry about RCA pre-out. If you want to add an external amplifier (or amp), I always recommend a unit with three pre-outs.

RCA pre-out voltage:

Usually this is specific to a pre-out spec. E 'measured in volts (which will touch on later). Basically, the tension is higher, the higher the music on your amp. Do not look at not as "free energy" because it is not. Moreover, the higher the voltage, the less noise that your system will be introduced. Again,This species does not matter if you intend to use an external amplifier. If you do not plan to use an external amplifier, try to find the highest voltage possible. 2 volts is basic, the 4 is a standard for a good, sometimes you'll see units with 5 volts. I know Eclipse units have 8V (!) Pre-outs. In short, more voltage = less noise and pure tone.

Digital correction time:

It 'used to simulate a perfect stereo environment. If you're at home, listening to the music you want to get inusing two speakers to get the best sound. The same goes for cars, except that it is a hell of a lot more difficult. Usually the speaker on the passenger side will be further from the ear, like the driver's side. Sound as it moves relatively slowly (comparfed to light), you have one ear receiving a portion of the sound to the other ear. The digital time correction delays the music a bit, 'so that the ears will perceive the same music simultaneously. This is a very important function asThey are planning an SQ system.

Crossover:

This functionality is built into many parts in a system of car audio. If your head unit does not have it, do not worry. Just to be sure that your amp has. Basically, it ensures the right speaker plays the sound correctly. Do not want to enter CROSSOVER later.

Equalizer aka EQ:

This feature allows you to adjust the sound. The most basic is a two-band EQ, and bass and treble controls. Some units have their heads3-Band, Low, medium, TREBLE. More sophisticated head units have 5-EQS band. If you are serious about creating the sound to perfection using EQ is not the head unit, will be an external device to receive and some of these units have 30 bands! I will not go into detail, much more on environmental quality later.

Theft Deterents / Security Features:

There are a few options when it comes to head of security:

Removable front panel:

The most common is a side pot. Basically,Remove from the heat of the unit (where the screen and controls), and the device will not work. This will deter thieves, but have no room in the car to leave. Thieves know most people, and will continue to violate your car, find your space and steal your head unit.

Password:

The other units have one password. When the device is broken into force, will be connected, the device requires a kind of forgotten. The unit does not work until thepassword.

Core CD:

Only a few units use a CD-key. It's actually the first time that the device used, the device will ask for a CD key. You insert a CD and unity means that the CD designation as a CD-key. If electricity is interrupted, the device will be prompted to insert the CD-key before it will work again.

Black faces by:

When the device is switched off, the main unit has a face completely black with no buttons or controls visible.Come on. Criminals are not so stupid that you can see that the main unit is still his face was not attached.

Hidden Faceplate:

E 'common for DVD players with screens and a device that I used to own, the Alpine CDA-7998 In essence, his face creases in the main unit, and looks exactly like a unit with front panel removed. Neat, but the unit is still vulnerable.

In short, all these tactics imperfect. Choose the one that has most meaning for you, but mostunits have only a function of losing the pot.

CD Changer controls / Optional interface:

This is a feature that allows you to connect other devices to the unit head. These units are often CD changers, digital music players, satellite radio devices, installation and video. With this function, the head unit, you will be able to add additional functionality to your stereo in the most convenient. But most of these interfaces are onlycompatible with the same mark. In other words, you need a head unit elevator with Ai-NET assembly connected to an Ai-NET CD changer.

Remotes:

Some head units have remote control capability. This is a useful feature because you can control the main unit, without taking his eyes off the road.

OK, so these are some of the characteristics of the main unit. Let's look now at the specifications for particular types of unit head.

TunerOrganizers:

Most of the unit's head AM / FM radio is integrated Check out this information on obtaining the best AM / FM performance possible.

Preset: This feature allows you to bring your favorite radio stations, save and recall them at once with the touch of a button.

HD Radio: A new model of radio, now the sound quality of CDs. Orphaned children, a radio broadcast their normal development, but with an additional signal provided by units with "HD radio can be received" option. Thethe availability of units with this feature is still small, and most radio stations have not yet embraced the technology. I do not expect this technology to break through, but because the sound quality is better, and not everyone wants to pay for satellite radio.

RDS: AKA "Radio Data System". A new feature of FM radio. This technology allows radio stations to send text messages to a receiver. This text can be used to show the title or station name, and the otherinformation.

FM sensitivity: the capacity of your unit to vote in a weak signal

FM Selectivity: The ability of your unit to reject interference from other stations.

FM Stereo Separation: The ability of a tuner to recreate the proper left / right channel sepearation.

CD Players:

CD-R / CD-RW: This feature ensures that the unit will play a CD-R or CD-RW, there was a CD recordingdevice.

CD-Text: This feature allows CD-Text data encoded in a series of CDs. This information includes the artist name, song titles and album titles.

MP3/WMA/iTunes Playback: This specification ensures that some digital formats can be played on certain devices.

ID3 Tag Display: Displays text (such as song title and album name) is stored in MP3 files.

DAC: digital-analog converter. This device takes the digital signal from the CD,and change it into an analog signal to your amp. The better the DAC, the higher the "true" sound will be.

CD frequency response: the frequency that your CD player can play. It must at least cover the 20Hz-20, 000Hz range.

Electronic Shock Protection: This feature prevents your CDs to run. If your head unit can not know, do not buy it. However, players have the most, and the technology has been pretty good lately, so it is unlikely thathave no problems with the district was.

Signal to Noise Ratio (S / N): a measure of how well a CD player silences noise. The higher the score, the less noise.

Zero Bit Detect mute: When the CD player, a sequence of 0 to detect CD (as between songs), it will automatically turn off the output. This feature is not really important, but is often advertised.

Oversampling: CD-Audio format has a resolution of 16 bits with a sampling frequency of44.1 kHz. What the hell does that mean? I really do not know, but think of a digital image. Zoom very close to this image and you can see the pixels. Think of each pixel as a sample. When you increase pixels, you increase the sharpness and image quality. When a CD player has oversampling, it takes 44.1 kHz, and changed to a higher number. More samples = More realistic sound. Confused? So I am not, but a unit with oversampling will sound better than one without. OfOf course, the good news is that virtually every unit in these days have this feature.

Tape decks:

Auto Reverse: A feature that automatically back up a band at the end of a role to play.

Dolby Noise Reduction: There are many Dolby technologies incorporated into tape decks. Most of these features are banded lower fiasco, and improves the signal to noise ratio.

Frequency response: Again, the recording frequency response. Tion by normal human hearingFrom 20 to 20,000 Hz

Wow and Flutter: This spec tells you how stable the tape deck playback speed.

Now that you know that some of the main unit, you're ready to buy the right unit for you.