What are the benefits and drawbacks of active pickups?

Question

I have two guitars, one with "passive" pickups and one with "active" pickups.
Although I looked on the web, I'm not really sure to understand what is the difference in terms of sound.
Yes, my guitars sound different and the "active" one sounds crappy if I remove the batteries but I'm interested to know what are the benefits and drawbacks of active pickups?

I see a drawback: it needs batteries!
And I'm not sure but I think that it has an easier tendency to produce a "larsen" sound (just personal experience during rehearsals).

Answer 1

http://www.elevation-music.com/guqu.html:

Passive Pickups: Passive pickups send a low output, raw signal to the amp that can only be affected by the volume and tone controls on the instrument itself. Passive pickups tend to lose the extremes of high and low frequencies, but still give a very even and punchy tone. This is because passive pickups tend to push out more midrange frequencies. While passive pickups might give players less dynamic control, their smooth sound is still very unique and desirable.

Active Pickups: Active pickups have preamps that are built into the pickup housing; so they can drive the signal to the amp themselves. This preamp must be powered by a source other than the amp, so active pickups require a separate battery to operate. This allows the pickup to send a higher output signal, producing a more complete, full-range sound than most passive pickup systems and giving players more control of instrument dynamics, projection and tone.

Answer 2

Another benefit of active pickups is they often have much lower noise than passive pickups. This isn't such an issue with humbuckers, since their two coils are wired in such a way as to cancel much (though not, actually, all) of the 60-cycle hum. But single-coil pickups often have a lot of hum, even when well-shielded, while active pickups typically have very little.

Answer 3

Active pickups drawbacks are that they don't necessarily react the same way to pedals in your effects chain which can put a load back on the guitar, especially the crucial first pedal. Personally I find that active pickups are great on acoustic instruments where you want a lot of dynamic range and clean and crisp tones, and you are working with a quiet and clean sound source. For electric guitars, I prefer passive pickups of various designs. If you like metal or shred, active pickups are the way to go. If you like more classic tones, you will probably want passive pickups.

Answer 4

Passive pickups have one big problem: they have a high source impedance. This means that they require a ridiculously high impedance input. A guitar premaplifier must ideally have an impedance of at least a million Ω (Ohms). Smaller impedances will cause high frequencies to suffer. As an extreme example, if you plug a passive guitar into a line-level audio input that has a 10 kΩ impedance, there is almost no high end.

Because active pickups incorporate an amplifier, their source impdance is very low. This means that the same tone profile will be produced by the instrument into any input: high or low impedance.

The high source impedance of passive pickups is also why guitar volume potentiometers ("pots") have high values like 500 kΩ. The value of a volume pot affects the tone: use a 250 kΩ, and there will be less high end. Active pickup systems can use small potentiometers like 25 kΩ or perhaps even smaller. These are physically smaller and more readily available in wider varieties.

The output of passive pickups depends on the strength of the magnet, number of windings and proximity of the string. A stronger magnet causes string pull, which can affect tone. The string being close to the pickup also affects tone. More windings reduce the high frequency response. Active pickups can provide lots of output without the artifacts of string pull or a rolled-off high end.

An attractive alternative to active pickups, however, is to install an on-board preamplifier in conjunction with passive pickups. A very effective preamp can be built using a single JFET transistor, powered by a 9V battery. A nice DIY electronics projects is to eliminate the battery by a phantom power system. The idea is that a DC voltage can be induced in the instrument cable, from which the guitar's on-board amplifier can draw current. I also seem to recall I saw a project once whereby someone built a guitar preamp entirely in the 1/4" plug of the instrument-end of the guitar cable, and had it phantom-powered. Every guitar you plug that cable into becomes active. Of course, that cable then only works with the special phantom power source. It looks like someone turned this into a product.

Answer 5

Passive pickups are more versatile when setting your volume and tone for different styles of music, just make sure you get the right type for the position on the guitars body. ex: I have a lace deathbucker at the neck, a lollar p-90 in the middle & a 2002 epiphone humbucker (flipped) from my old les paul standard at the bridge.

Active pickups are more reliable for recording, their tone won't change when setting volume and tone, they also start to lose their abilities when battery gets at half used and progressively gets worse as the battery dies.

Honestly nothing beats a passive, I have experience with many styles of pickups and when playing metal, punk, death metal, black metal, blues, rock, progressive rock etc... passives do not disappoint.