Adding multiple piezo pickups to my electric guitar?

[RedJamaX]

I will be adding an under saddle piezo pickup to one of my electric guitars soon and was wondering if there is a benefit to adding a cigar box piezo with it as well?  or what about adding two under bridge pickups right next to each other?  does that increase out put or sensitivity?

 

[WRGKMC]

Overkill. You'll likely find one is better than the other and the second detracts from the first when they are both used. I used a disk type in an acoustic, the later added an under bridge type. The dick not only sounded muter its had phase problems with the under bridge piezo. Sound doesn't travel instantly throughout the body and the pickup closest to the string will produce a signal before the more distant pickup.

Its not much but it does cause the same kinds of problems with phase two mics do recording the same  source of sound. In my case, I had placed the disk to the right of the bridge and slightly towards the treble side. If I had installed the disk after the bridge and moved it around to find a sweet spot that complemented the first it could have worked out. Since I glued the disk into place I' stuck with frequency and phase cancellation. If I turn both up it sounds awful because the tones cancel each other and makes the tone sound muted and plastic.

It was unexpected and it took me awhile to figure out it wasn't only a tone issue. If you picture a lake and you throw two stones in different parts of the lake, when the waves meet up they may become additive and increase in size or they may be subtractive and the upstroke on one wave cancels the other out. Strings vary in frequency vibrating the wood, so you wind up getting some notes that are additive and loud, and others are subtractive and dead. Using two contact pickups spaced apart is a bad application. You may be able to use two disks set on either side of an acoustic bridge for some stereo like effect but Its likely to fail because the sound board conducts sound from all the strings.

On a solid body, I just don't see any benefit. If they are close together, you wont have the phase issue but they wont have any variance in tone so why bother. You get the best sound quality off the saddles themselves so they will produce the best tone. If you're placing the transducer under a Tele or Strat type bridge, the tone isn't going to be as good, as it could directly off the string saddles. You'll likely have to blend it with the guitar pickups to be useful for most stuff. Having a second transducer will require a second preamp and mixing the two signals wont add much you couldn't get with a EQ preamp combo.

You could adjust two preamp/EQ's differently but its pretty futile unless the sources produce different tones. Guitar pickups produce different tones along the string and they blend together for different bass and treble tones. The single Piezo can be blended with those and give you even more variety, Having a second piezo close to the first capturing the same tones is redundant. Its not going to function like  humbucker vs. a single coil and have different tone and the preamp circuitry is expecting to see a specific impedance. If you double the load, both become less sensitive and additively produce the same signal strength. 

[Graeca]

Another option is to install a piezo into the neck, itself...Frank Zappa did this with one of his Strats.