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Another Way To Mount A Piezo


Dugz Ink
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I recently bought a K&K "Big Shot" piezo pickup, to mount in my acoustic/electric bass. I was looking to add to the sound that I get from the undersaddle pickup.

If you don't already know, let me explain that piezos react to vibration, so you have to mount in such a way that it either A) picks up a lot of sonic energy from the sound source (in this case, the strings), B) picks up a lot of resonance from the instrument's body, or C) all the above.

The problem with "A" is that it can also create a lot of feedback if the piezo is too close to an opening... much like putting a mic near the opening of an instrument... so you have less trouble if you keep the piezo buried some place safe.

The problem with "B" is that the piezo will pick up ANY vibration, including the sound of your arm rubbing against the guitar body... much like trying to record vocals while holding a Neumann U87 studio mic with your hand.

Another interesting property is that piezos respond best when there is a little bit of pressure on them; they pick up more of the low frequencies and do a better job of picking up all frequencies as you increase the pressure. Well, up to a point. If you apply too much pressure, then the piezo cannot vibrate, which keeps it from doing anything.

So, with all of those properties in mind, I designed and built a chassis that would hold the piezo tight, shield it from direct sound, and pick up more sonic energy.

Here is a simple graphic of what I built:

piezo-chassis.gif

The "soundboard" is a piece of solid hardwood that is about 1/8" thick. The "pedestals" are two hardwood dowels. I haven't included dimensions, because that would really depend on what you mount this in; the amount of space you have for mounting, and the amount of space you have for slipping this in so you can mount it.

The two bolts (that hold the piece of wood that holds the piezo) can be tightened until you get just the right amount of pressure to provide the best sound. I also added a thin rubber pad between the piezo and the wood*, which seems to enhance the piezo's ability to vibrate properly.

Over the course of several days, I tried sticking the piezo to the guitar's body, clamping it to the guitar's body, and then mounting it in this chassis. The chassis worked the best by a long shot, and provided incredibly deep lows... the kind that shake subs.

However, it's not the sound that I want for this guitar, so I'm looking into mounting a mic in the body. However, I am holding onto this chassis for other guitar projects, and I'm thinking about making a similar rig for mounting a piezo inside a djembe.

I just thought I would share it, in case anybody wants to experiment.

D~s

*I failed to mention that only used one rubber pad on one side of the piezo.

Edited by Dugz Ink
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How is this chassis mounted to the guitar?

I used two small blocks of wood and screws (attached to the feet of the pedestals) to clamp the chassis into the soundhole. You could also drill holes in the body, then run screws into the pedestals, but I don't have the heart to drill holes in a beautiful acoustic guitar.

I also used rubber padding between the pedestals and the body, which reduced the amount of noise that was transfered from the body, but it also cut down the sound quality (probably because the rubber sucked some of the energy out of the soundboard), so I'm not sure if you would want to "shock mount" this thing.

D~s

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OK...so what is the thinking behind the large rectangle piece being so large? Why not just mount a piece of wood just a little larger than the width of the pedestals? Bass response? (I keep having to remember that this is for an acoustic bass....)

Are you plucking the strings with your fingers in the usual way? Or using a pick?

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Dugz-- I get it now! I was thinking of electric guitars to begin with; hence my confusion. :D Cheers for this idea, then-- I've been wanting a new soundhole pickup, and this might do the trick!

Greg

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Very clever! I'm gonna definitely file that idea away for the appropriate project -thanks! The djembe idea sounds like a great solution for a problem child - I've never had good luck getting one mic'ed without an epic struggle, and that sounds simple, portable and practical.

Out of curiosity, since you mentioned that this didn't give you the sound you were looking for, what didn't you like about the results on the bass, if you don't mind sharing?

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Might have to order one of the Bugbrand Piezo elements. It's just the same thing you could do yourself with a jack and a Radio Shack buzzer, but the work's done for you and they don't mark it up an insane amount.

Bugbrand Site

No deep-linking, so you have to go to the "audio products" page and scroll down a bit.

On the other hand, there's still the Radio Shack option... 5 quid plus shipping actually gets close to $20 CDN... which may make the convenience of having it ready-made not worth the trade-off after all.

UK residents would benefit, though!

Greg

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I'm interested in the posibilities of using piezo's on electric guitars. Recently I got a good sound with little of the handling noise and quite a bit of bass by wedging a "buzzer" element into the neck pocket of a strat. What I didn't mention wherever I last posted about this is that, I had shimmed up the neck and used icypole (ice-cream sticks) to do this. The piezo was able to vibrate between these sticks so that, even though the neck was screwed down tight, it was still able to vibrate.

I'm definely going to look into this kind of "alternative" mounting further. It occurs to me though that the same type of principle as was described here was at work in that it allowed a controlled amount of vibration of the element.

anyway, my 2c

psw

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I really suck at visualizing lately. First I didn't know what Dugz was doing, and now I'm not sure what YOU were doing. :D

So you took 2 icecream sticks, put the piezo in-between them, and then stuck them all into the neck pocket, between the neck itself and the body pocket? :D

I feel so inept at imagining all this. <chuckle>

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So If I wanted to mount this onto my djembe I would stick it where I want it than put something behind it that has two bolts on it that go through the djembe and I can change the tension by turning the nuts outside of the djembe? Is this correct? I play djembe all the time but It is a bugger to mic and still be in a good playing posistion.

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Wondering out loud ...

If you attached a piezo to the trem block on a Strat would the spring vibration cause it to feed back? You probably wouldn't want to use the trem with the piezo on, I'm thinking, because of the spring noise. I don't know, just wondering.

Any thoughts?

I dont think it would sound very good. Very metalic and not very acoustic if thats what your going for.

BTW I just orderd the Big shot for my djembe. I will tell you how it goes when I install it! :D

Edited by Godin SD
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  • 2 weeks later...

Bump :D

I've ordered a contact transducer (waiting, waiting) to try out on the trem block of my MIM Strat.

I'm thinking that I can run the cable out the back through the trem cavity cover and use the Fishman outboard preamp I've had for a while. Then run either an ABY to my pedalboard or straight to the PA.

If this works it will solve a bunch of problems, since I don't like taking my acoustic out to bars and there's just some times you need an acoustic sound.

So, any thoughts before I go screwing things up? :D

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My exposure to piezos goes back to '61 when I needed an electric banjo. I shall now humbly apologize for my past sins. Vega sold a pickup that you saddled around the wooden through-piece behind the skin-head. It was about 2" in diameter and ugly as sin but sounded WAY cool! No, seriously. Since that time I have installed piezos in pianos, cellos, basses(accous. and elec.) and toilets. The placement seems to be THE thing. Last year I was given by one of my music-store customers an old Pintech AP10 piezo unit that I use to find the sweetest place to install a PUP. I just hook it to my Vintager 112 (you can't hide money) and play away with different placements. I have been AMAZED at the places where instruments, in particular basses, have the best resonant output! I think piezo is the wave of the future, sonically. Place 2 or 4 of them in different places for different sounds/tones. You go, folk!

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Hmmm...amazing what you miss when you've been away....

Greg P

"So you took 2 icecream sticks, put the piezo in-between them, and then stuck them all into the neck pocket, between the neck itself and the body pocket?"

Exactly, that's exactly, exact...now relax :D ...visualize...that's it...exactly... !

Of course I used icecream sticks cause they were handy (I save them to mix epoxy) and were just the right size to lift the whole neck without tilting to fit my sustainery thing on anyway (so the sticks were already in there, and the guitar set up accordingly).

A similar result could be had with something real thin with a hole over most of the piezo (it wount need to move much to pickup vibrations) or perhaps a small indentation or extremely shallow hole drilled in the bottom of the neck pocket and a bit of a groove for the wires (plus a hole into the neck pickup cavity to take the wires inside).

TREM BLOCK PIEZO INSTALATION...THIS IS THE POST!!!!!!!!!!!!!!!!!!!

Tremolo bridge piezio Tutorial by Bear

This post get's hidden away at the back of the solidbody and bass chat section ... so, a little tricky to find if you didn't know to search only that section. Also, unless it's my ancient rusty computer, I think the images have gone B) .

Basically he took two piezo's wired together and epoxied them to the spring side of the trem block and wired them out with thin shielded cable. But what a fantastic looking bit of work bear did. The whole block was encased in epoxy and the thing looked indestructable, and he took pics as he went along...still, strong double sided tape would work also!

There was some follow up and the guitar was sold but I don't remember where I saw that. He did in the end need a buffer. Even though I can get a reasonable sound output out of the straight piezo down 10' of lead into my amp does not mean that the sound is good and true or that it wont load the other pickups down with it's high impedance.

Last time I played with piezio's I used a little compressor thing I built, but just about any stomp box has a buffer stage in it so run it into something like that as close to the piezo pickup as you practically can. I'll have to do a little more work on this sometime...priorities!

My concern is with the amount of noise you get from bridge mounted systems with bridge damping etc. I made some under saddle type things (too hard by the way) to get a hex output, same problem with handling noise. The other thing is, I don't know about you guy's, but my trem springs don't give off reverb...just squeaks and boings occasionally that I really don't want amplified at high volume!

BTW, Pevey's new telecaster style guitar has saddle pickups and a neck pocket pickup to get it's acoustic sounds...and Zappa did mention he'd stuck one up the neck, many moons ago.

:D Doc...toilets....what kind of sick individual...errr, where do you place them by the way B) ! The "wave of the future"...must have been the flush. Stay away from banjo's my friend, there's a good chap.

Actually though, look at the variax...piezo's with digital modeling of everything...perhaps your right... Had Leo Fender discovered piezo's he probably would'nt have gone to all the trouble and expense of winding all those pickups and the amps of today would be purpose built for piezo input.....and we'd all be playing banjo's on the side to get a more "electric" sound :D

Hmmm...time to go away again

pete

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I got mine about 2 weeks ago and have monuted it just about everything I have that makes sound :D I found that it sounded best on my electric on the headstock. That gave me the warmest most "acoustic" sound from it. On my djembe I mounted it on the head about 3" from the rim and it sounds AWESOME. It sounds just like my djembe just louder. I also mounted it on my acoustic with great results. So It looks like I need to buy more of these things :D

I do recomend getting somekind of preamp for it as it's not very loud. It's plenty loud for me practicing with some friends but not loud enough for a full blown band thats cranked.

Edited by Godin SD
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  • 3 weeks later...
It comes with a very sticky double stick tape that I mounted it with.  Just make sure you don't go too far in or else you will get feedback at high volumes.

Have you ever thought of mounting it in a routed or carved channel in the headstock or body or even the neck?I am talking like a permanent mount where it is covered and cannot be tampered with. Such as possibly covering/filling the piezo/routed area with "putty/filler before finishing the guitar.

I have never used a piezo pickup but I have read alot about them. I have read about people making one out of a radio shack part.

Do you always need a EQ with one?

I like the idea of only having one or more piezos in a guitar, I think I would like the "clean" look! :D

Backwoods :D

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It comes with a very sticky double stick tape that I mounted it with.  Just make sure you don't go too far in or else you will get feedback at high volumes.

Have you ever thought of mounting it in a routed or carved channel in the headstock or body or even the neck?I am talking like a permanent mount where it is covered and cannot be tampered with. Such as possibly covering/filling the piezo/routed area with "putty/filler before finishing the guitar.

As long as I dont forget to, im putting one between the 2 halves of my new body im gluing up this weekend, Ill make the cavity for it so it will be just thin enough to apply pressure to the piezo when glued up, and have a little allen screw in the control cavity that I can adjust the pressure with, and if it turns out to be rubbish, oh well, take out the allen screw, fill the hole, and nobody will no its there.

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Backwoods...I put a piezo in the neck pocket of a strat and you can mount them on the bridge and other locations too. It's a simple, cheap device but not an "electric" guitar pickup substitute...nor is it really acoustic.

You will need some kind of preamp too, but it can be quite simple.

As Mr Alex is doing...and I'll be too...is worth it for a couple of bucks. Putting it on the headstock involves problems with running the wires through the neck. It's likely you'll need some extra controls for mixing and turning on the piezo too.

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