is my pup a microphone!!???

[cloren]

Ive never experienced this before in any bass Ive played: my neck pup amplifies the sound of me tapping on it. thats not the case with the bridge pup- thats not the case with any pup ive ever played through!

whats the deal- I know my finger isn't magnetic, so why is it amping my finger?

[joeyl]

it probably has loose wiring in there, and the tapping is causing them to move.

http://www.guitarnuts.com/technical/...ical/index.php

[joelb79]

Tapping could also be loose mounting or bad potting.

[cloren]

interesting, i'd place my bet on faulty soldering- i paid my little brother's friend $20 to do it. I think he probably knew about as much as I did (i.e. not much)

I guess the next step would be to take it to an electrician.

[wdinc01]

And to get your $20 back

[Fnord Explorer]

You can actually talk into magnetic pickups and it will pick it up. I forget who did it, but someone actually recorded vocals on a song that way.

[joelb79]

So wait he soldered the pickup to the pots, or wires to the pickup? My vote still goes towards the mounting is loose. The foam on the bottom if its not pressing firmly against the cover causes the coil to move when you tap on it. Quite common actually.

[cloren]

holy crap. i think you hit the nail on the head dude. the mounting is not firm at all- actually i cut out some foam rubber and glued it to the preexisting foam moanting pad to add some height to the pickup- also i only have 2 screws keeping the pickup in place (the other two had striped heads- im awaiting replacements)

all in all, it's a pretty shoddy looking setup (sounds great though)- but if what you say is true about faulty mounting leading to this type of problem then I think the problem is easily remedied

[joelb79]

It should be easily remedied. I would put all 4 screws in it, and make sure you have a nice firm amount of foam behind the pickup.

Just for reference, I've had foam that bottomed out before. When I turned my amp up loud enough, it fed back I could actually see the pickup move. Mounting makes a HUGE difference in your tone.

[TrevorOfDoom]

Originally Posted by Fnord Explorer

You can actually talk into magnetic pickups and it will pick it up. I forget who did it, but someone actually recorded vocals on a song that way.

a friend of mine screams into his during one song. makes one hell of a ruckas, and it sounds awesome!

[Deluge Of Sound]

Originally Posted by Fnord Explorer

You can actually talk into magnetic pickups and it will pick it up. I forget who did it, but someone actually recorded vocals on a song that way.

Nirvana's Territorial Pissings.

http://youtube.com/watch?v=0CKiHdH5-ec

That's Krist singing into Kurt's pickup at the beginning.

[elros]

A proper magnetic pickup should not make a sound when you poke it with your finger. None at all. If it does, it is microphonic, and that's not good. As has been mentioned, this can be due to poor (or absent) wax potting. Cheap old pickups sometimes aren't potted at all. And I've played a rather new Epi Thunderbird on which both pickups were very microphonic. That sucks.

However, if the pickup moves when you poke it, then it moves in relation to the strings, and this would produce a sound like a thump in a proper pickup. Makes sense?

[Audere]

From a technical stand point - moving the string relative to a fixed pickup is the same as moving the pickup relative to a fixed string.

All standard pickups (even with fixed coil wires) move around at some level.
The question is the amount (sensitivity) and any mechanical dampening vs frequency etc in the mounting.

Movement of the coil relative to the magnet either by the wire moving or the magnet moving is a 2nd effect which is often vibration (sound) sensitive.

[cloren]

that makes sense to me- pickups I put in were Nordstrand NJ4s which don't have anything to seal it- the casing is very loose due to the lack of all 4 screws keeping it steady- I love the sound of that neck pickup soloed but to play it safe I'm gonna replace the foam mount as well.