midnightblue97

Searched, but didn't really find what I was looking for. I'm not really into car audio, therefore I don't know **** about it, but I'm planning on picking up a cp-mp3 deck soon because I'm sick of listening to tapes. I'm looking at a flyer right now and a couple of the decks I'm looking at advertise 1-2-or 3 preouts. What the **** are they and what do they do??I assume that they are really only for a car thats got a big system in them to power amps or subs or something??

mazdaspeedwest

to add:
they are signals that come from BEFORE the internal amp, in the form of RCA cables. When they say 1, 2 or 3 sets, it's referring to FRONT/REAR/SUB. If it's only one set, it will be REAR. If 2 sets, then FRONT/REAR. Usually the 3rd set is non-fading for the subwoofer. This means that when you use the fader on the deck to fade between front and rear, the sub preouts are not effected by it and won't change. Some decks, when you fade, the sub channel will fade aswell, not a good thing, IMHO. and yes, these are ONLY used if you are using external amps (the decks speaker wires will not be connected), otherwise the decks internal amp will be used and the speaker wires from the deck will be connected.

the low voltage BlueLEDz refered to can be as high as 8volts, but generally, they are ~5volts.

When you see an amp that has "high level input" this means, high voltage, or speaker wires. The speaker wires can be as high as 10-12volts and most amps could not handle that high a voltage in the RCA input.

midnightblue97

O.k. I think I might have it.
In addition to the wires that go from the deck - amp- then to wherever, the preouts supply power to the amp.
Kinda like the speakers on my computer where in addition to plugging them in to the back of my computer, I also have to plug them into the wall for power??
If thats right then I learned something, if not then I didn't understand really, but it doesn't matter that much, because any stereo equipment that I may get any time will probably be installed by the place I get it at or by a couple of my friends that know a whole lot more about it than me. thanks for the replies and ****.

DaleK

Actually this is backwards - the preouts are the audio signal from the deck to the amplifier, and the power connections to the amplifier are made separately to the car's wiring/battery. The preouts are the same as the wires on your computer speakers that go from the speakers to the audio output on your PC.

mazdaspeedwest

right, ok let's simplify even furthur

your PC = the deck
signals only, no power

your PC speakers have 2 things, A- an amp and B- speakers. So the connections are made inside the encloseure and all you see is a signal cable or plug and a power cord. but in car audio, you'll generally have a separate amp and speakers set up. (there are exceptions, like Bose et al. factory systems or powered subwoofers)

so the signal goes from PC to speaker AMP, then gets set to the speakers. Like in car audio, the RCA cables (preouts) transfer that signal from the deck to the amps. As stated, the amps are then connected to the cars power and speakers via other cables. (like the power cord on your PC speakers)

once the amp gets the low voltage signal from the RCAs and has all power connected, it then feeds the speakers with high voltage signals and you get the sweet sweet tunes

Party on Blue!

pr5owner

uhh preouts are basicaly the signal directly picked up by your laser (which reads the cd) before it goes through the built in amplifier of your deck, the amp in your deck is really noisy and adds alot of distortion to the power it gives out so thats why you use preouts for a cleaner signal. preouts are usually interfaced to an RCA type connector

mazdaspeedwest

well with that said, any signal is whats picked up by the laser....

but it's not directly from the laser. the signal goes through an digital to analog converter first, as 99% of amps are analog and not digital and wouldn't know what to do with a digital signal.