Explain pickups to me?

Discussion in 'Pickups & Electronics [BG]' started by ImJustDez, Mar 22, 2014.

  1. ImJustDez


    Dec 1, 2012
    New Jersey
    So I'm trying to learn way more about bass than just playing and I dont have a teacher nor bass playing friends to show me these things. I wanted to know what exactly a pickup does and what different pickups do. I'm asking here instead of googling it because I rather learn from people than receive misinformation by mistake.
  2. M0ses


    Sep 11, 2009
    Los Angeles
    A pickup is a magnet surrounded a by a coil of wire. It is essentially an electrical generator on a small scale. The oscillating movement of ferrous metal (strings) within the magnetic field induces an electric current in the coil. That's your signal.

    Factors that may go into the frequency response of a pickup:
    shape of coil
    thickness of the wire
    how many turns/windings the coil has
    strength of the magnets
    exact shape of the magnetic field

    Probably plenty of other factors that aren't popping into my head instantly.
  3. Moses has it pretty much covered!
    Another factor is also the insulation of the wire.
    Tall thin coils have a focused tone, while fat flat coils are the opposite because they cover more string.
    More turns means less highs, but more output.
    A stronger magnet also means higher output.
  4. eriktheviking


    May 5, 2013
    If you put two single coils next to each other wound in opposite directions, you get a humbucker.
  5. ImJustDez


    Dec 1, 2012
    New Jersey
    Also, what do people mean by Active and not active? Idk if it applies to pickups, I think it does.
  6. This is more in the spirit of being helpful than some kind of jerk. Really. You should read through the Pickups FAQs at the top of this (Pickups & Electronics) forum. Packed with goodness, it is!
  7. eriktheviking


    May 5, 2013
    Active means there is a preamp on board. This means you need to put a battery in your bass, but it gives you the ability to boost frequencies rather than just cut then like on a passive bass.
  8. bluesdogblues


    Nov 13, 2007
  9. ImJustDez


    Dec 1, 2012
    New Jersey
    Ya know, I have a battery on mine and I always wondered what it was exactly for.
    I have a MusicMan S.U.B. Series stingray 4 if you guys are wondering on my bass
  10. ImJustDez


    Dec 1, 2012
    New Jersey
    Okay yes I shall, thank you
  11. hrodbert696

    hrodbert696 Moderator Staff Member

    Like M0ses said, what you have are metal strings vibrating over a magnetic coil (the pickup). That generates a small electric current in the pickup which perfectly matches the frequency the string is vibrating at; the cable then carries that current down to the amp to be amplified and retranslated into sound via the speaker.

    Most bass pickups are either single-coil or humbuckers; in general, single-coils have a little more "bite" to them but a single-coil by itself will also generate a low humming noise; that's why jazz basses have two of them, if they're both on full they cancel each other out and don't have a hum. A humbucking pickup doubles the coils so that there's no hum in the first place; they also have a somewhat rounder, warmer tone with less bite in it. Sometimes you'll see a bass with a coil tap, which means it has a humbucking pickup but you can isolate just one coil for the single-coil sound by pulling a knob or flipping a switch.

    There are some guitars with active (= powered) pickups, but hardly any basses have them. 99% of the time "active" bass means that a preamp has been added to the instrument; basically a tiny amplifier that can increase the signal and, more importantly, control its high, middle and low frequencies before sending the signal on to the actual amp. It needs a 9v battery (sometimes two of them) to power the preamp.

    As others have said, there are a gazillion engineering variables that give each brand of pickups their own individual character; thickness of the wire, how many windings, etc.
  12. ArtechnikA

    ArtechnikA I endorsed a check once... Gold Supporting Member

    Feb 24, 2013
    As long as we're going for completeness, there is also the piezo pickup, which uses the vibrations themselves to create a signal.

    Some basses (and other instruments) have multiple kind of pickups installed.

    So - magnetic, which uses the vibration of a metallic string in a magnetic field to create an electrcial signal;
    piezo, which uses the mechanical vibration directly to create a signal;
    optical, which reads the vibration of the string to produce a signal.

    There are active pickups, but they are few. All that really matters at this level is whether or not the -instrument- is active (has a battery-powered preamp) or not.

    Definitely read the FAQ...
  13. To get a handle on what all this means in the real world you just need to play a buncha diff basses w diff pickups on em, preferably thru the same or very similar amp. Compare them in passive mode if possible to take away the varables that the active circuit introduces. Then compare some active basses.

    You made a good choice with the Musicman. The MM humbucker is a great pickup with a signature sound all its own. Just as valid as any other choice if you like it.
  14. zontar


    Feb 19, 2014
    Coils can also be wired together in series and in parallel.
    For Humbuckers the coils are typically wired in series-that means the signal goes through one coil and then the other.
    Parallel means that the signal comes from both coils at the same time.

    I have series/parallel options on two guitars--when I choose series it sounds like a normal humbucker, when I choose series it sounds like two single coils next to each other. The signal has a lower output, and it's more susceptible to noise-as compared to series.

    But they both have their uses, and I use both settings.