The Difference Between Single Coils and Humbuckers.
General knowledge.
Pickups are essentially magnets. Your strings are made of magnetic metals; usually electric guitar strings have a steel core wrapped in nickel, or are just plain steel. Your pickup creates a magnetic field that when the strings move, disturb. This disturbance is transferred to an electrical signal by your pickup, effected by all your guitar's electronics and eventually reaches your amp and is turned into vibrations which you hear as your guitar.
Pickups get their magnetism from either a magnet attached to their base, or from magnetic pole pieces. Pole pieces are the metal cylinders that come out of the pickup under each string. The pole pieces are wrapped in magnetic wire (usually copper), which increases the strength of the magnetic field. One set of pole pieces wrapped in copper wire is called a coil of a pickup.
There are 3 main types of magnets used in passive pickups; Alnico II (2), Alnico V (5), and Ceramic.
Alnico II is the lowest output and the smoothest/warmest/bassiest of the 3 main magnet types. Alnico V is higher output than Alnico II and has more trebly/midrange bite than Alnico II. Ceramic is the highest output of all and the most trebly/biting. In general, Either Alnico II or Alnico V can sound good distorted or clean, but ceramic pickups generally produce a tone that isn't as pleasing clean, but somewhat preferred for heavy distortion.
Depending on the type of wire used to wind the pickup, it's thickness, how it was prepared and how old it is, the wire can affect the pickup's overall sound greatly. Companies generally do not list information about what wire type they use in order to keep their pickup formula somewhat guarded. In general, the more wire that is used will give you a greater output and a bassier tone.
As you may have noticed, if you pick closer to the bridge of your guitar, the sound you get will be quieter and more trebly than it would be if you picked closer to the neck. When pickups were first made, they didn't account for this and your bridge pickup would sound very quiet and trebly, while your neck pickup would sound very loud and bassy. Eventually, people began to realize that if you over-wound the bridge pickup, so that it became hotter and more bassy, and under-wound the neck pickup, so that it became quieter and more trebly, that you could create a greater balance between the pickups. In general, bridge pickups will still sound more trebly than neck pickups, but not in all cases.
So, now that you have some general knowledge, we can move on to the pickup divisions.
There are 2 main different pickup constructions, single coil and humbucker (2 coils). Single coils and humbuckers come in all different sizes and shapes.
Here are some various single coil pickups.
http://www.seymourduncan.com/website/images/sp90-1.jpg
http://www.seymourduncan.com/website/images/STL-1.jpg
http://www.seymourduncan.com/website/images/sld-1.jpg
http://www.seymourduncan.com/website/images/ssl-2.jpg
Here are some various humbuckers.
http://www.seymourduncan.com/website/images/SHR-1b.jpg
http://www.seymourduncan.com/website/images/ST59-1.jpg
http://www.seymourduncan.com/website/images/APH-1.jpg
Hopefully you know, visually, the difference between humbuckers and single coils now.
The first pickups created were single coils. Along with picking up signals from your strings, which they were supposed to, they also picked up stray radio frequencies (RF) which you would hear through your amp as an annoying buzzing sound. The orientation of this RF signal is related to which way the wire is wound around your pickup. Meaning that if you wind the pickup clockwise, the RF signal will travel in a different way then it would if you wound the pickup counter-clockwise. If you have 2 signals being used at once, where the RF signal is different in each, they will cancel each other out, or at least lessen their collective sound greatly.
This is why humbuckers were created.
Humbuckers are essentially 2 single coil pickups that share a large magnet at their base. Each coil of a humbucker is wrapped differently, so that the RF signals they create cancel each other out.
The only purpose in creating humbuckers was to "buck" the hum that single coils created.
However humbuckers did not, and do not, sound just like single coils without hum. Since a much larger magnet was used, and there were 2 coils of wire, the humbucker created a much louder signal.
There are many other differences between humbuckers and single coils. Some will say that humbuckers are only good for distortion and single coils only good for clean. This is only personal taste, and many people (There are too many people who use Gibson style guitars for clean to begin to list them) use guitars with humbuckers for playing clean. Also, guitarists such as Ritchie Blackmore (Deep Purple), Tony Iommi (Black Sabbath), Kirk Hammet (Metallica), both of Iron Maiden's guitarists and many others have used single coils for metal.
I could begin to describe the tonal differences of humbuckers and single coils to you, but it would be best if you went out and played alot of guitars and found them out for yourself. I could say single coils have more "quack" or "twang", but what you think of as quack may be different than what I think of, so it'd be best you come to your own conclusions.
These links have clips of many different pickups, use them to help you make decisions about pickups
www.toneninja.net
http://www.soundclick.com/pro/?BandID=112334
http://artists.iuma.com/IUMA/Bands/Forum_Music
http://seymourduncan.com/forum/forumdisplay.php?s=&daysprune=&forumid=5
The Difference Between Active and Passive Pickups
Pickups in general
http://mywebpages.comcast.net/skgs/sk/pickup_factors.htm
Go to that website for information about factors affecting how a pickup sounds.
Potentiometers are the technical names for your controls. The lower their value, the more high end they cut off. So a 500k pot will sound more trebly than a 250k pot, and a 100k pot will sound more trebly than a 25k pot.
Passive Pickups
Passive pickups were the first kind of pickups. They generate a signal which is powerful enough to drive an amp and loud enough to be used without any pre-amplification. They have many more winds of wire than active pickups and much stronger magnets. They are more prone (but won?t necessarily have) to having microphonic feedback. Microphonic feedback in your pickup is when there is too much vibration in the coils of your pickup and you get that annoying squealing sound, though some like it. Since passive pickups have more wire, there?s more of a chance of there being an error somewhere and something being microphonic. Also the stronger magnetic field increases chances of being microphonic as well. Passive pickups generally use potentiometer values of above 250, and sometimes don?t have potentiometers.
Active Pickups
Active pickups on their own are much weaker than passive pickups. They have a much weaker magnet and much fewer coil windings, which means their signal is very trebly and very low output on their own. They have built in pre-amps (which is what the battery is for), which brings their output level to one similar to, and in many cases greater than those of passive pickups. They use much lower value potentiometers because the signal is so trebly and a lot of the high end needs to be cut off to be usable. Active Pickups use pot values usually below 250k; anything too great will give a signal that is far too trebly and basically useless.
Each has their pros and cons. The main argument for passive pickups is that they sound more genuine and that you don?t have to change all your electronics to change between passive pickups, since most guitars use passive pickups to begin with. The main argument for active pickups is that they don?t have feedback, sound more hi-fi and the tone isn?t altered much with the volume controls. The main argument against passive pickups is that they?re microphonic and pull too hard on the strings, reducing sustain. The main argument against active pickups is that they sound sterile.
Neither is by default better than the other, and plenty of artists in most any genre will use either type, though passive is more common.
I have a built-in Soundcard so it may not be able to hold the Guitars requirement
