<p>This is an apples and oranges situation. Piezo based pickups and the speakers from a portable radio operate on entirely different electronic phenomena so cannot be compared based on their sizes. Piezoelectric materials generate voltages directly based on force applied to them. The coils in speakers react to/generate voltages based on moving magnetic fields. Old telephone voice pickups use a third method that has a base voltage which a carbon granule pickup then modulates based on sound pressure (though they may generate a weak signal on their own) so even more difficult to incorporate. And finally typical guitar pickups also use coils to generate electrical signals, but not from air vibrations pushing a diaphragm pushing the coils but by metal strings vibrating over them.</p>
<p>To answer the question; no, you cannot use an old radio speaker as a piezo pickup because it is not a piezoelectric device. Yes, both can be used to pick up vibrations but piezos do it by directly converting the vibrations of whatever it's attached to into voltages. With the speaker you would need a moving diaphragm or similar to mechanically convert the sounds to something that will move the coil (which the speaker cone can do). You would basically be turning the speaker into a microphone. The latter might be interesting in the way one incorporates the speaker into the sound box of the guitar. It may also be possible to turn the speaker coils into a crude electric guitar style pickup and lose the speaker diaphragm entirely.</p>
<p>Even within the piezo pickup community there are debates on whether they sound any good or not. So the only way the bigger question here can be answered, whether your cigar box guitar will sound better with a piezo or a speaker/microphone pickup, is through experimentation. You would have to try the different things to see which sounds more like what you want. A good start would be learning how the different electronic devices work on a fundamental level so you can use them effectively when designing your instrument.</p>

CC BY-SA 4.0
2024-07-31T13:00:26.447Z
2024-08-14T11:15:54.630Z
2024-08-14T11:15:54.630Z
rebusB
<p>I'm making a cigar box guitar, and I need piezoelectric pickups. You can buy these for around 90 cents on the Internet, but you can also use the speaker from any small electronic device, like a telephone, a clock radio, or even a digital watch with an alarm.</p>
<p>I unfortunately didn't pick up some old telephones when I had the chance, but I do have some old transistor radios. The speakers aren't that big, about 4&quot; in diameter, but they're much bigger than what you'd usually use for piezo pickups.</p>
<p>I am thinking this might work really well or really badly. On the one hand, bigger pickups could make for a meatier, punchier sound, which would be great because cigar box guitars are an amateur project not known for precision. But on the other hand, being bigger could mean they're less sensitive.</p>
<p>Does anyone have any advice on whether this would work or not?</p>

CC BY-SA 4.0
2024-07-31T11:37:29.810Z
Quite obviously, this question belongs to https://electronics.stackexchange.com/. But  "Close" or "Flag" do not give me the option to provide the link :( Someone with enough rights should move the question there, I guess.
virolino
CC BY-SA 4.0
2024-07-31T12:41:07.647Z
@virolino That might be the more logical option, but I see no reason for it being off-topic here: it's a creative project, during which the OP encounters an obstacle, and asks for insight. I would ask the OP to see if Electronics.SE is a site where they would get more constructive/helpful/appropriate feedback, however. If so, let us know, and we can migrate it.
Joachim
CC BY-SA 4.0
2024-08-01T06:02:02.833Z
@Joachim: the whatever OP is building fits to this site, probably. But when we go to the details of radio speaker vs. piezo pickup, then better answers can be gotten there - that is the purpose of that site. That is the only reason I suggested that. They can help better even with the proper interface circuits and stuff. And I made the proposal for moving, exactly because it is a beautiful question.
virolino
CC BY-SA 4.0
2024-08-01T11:04:44.290Z
@virolino Then I misinterpreted your comment, for which I apologize :) I'll wait for a response from the OP before acting on that suggestion, though.
Joachim
CC BY-SA 4.0
2024-08-03T14:00:16.610Z
@virolino This question does have feet in both electronics and craft, but there are plenty of projects that do. I think the OP didn't do much ground work before asking so the question is a little broad and could go either way. I tried to answer the craft side by discussing the basics of the devices and how that would effect their use.
rebusB
CC BY-SA 4.0
2024-08-21T16:13:13.050Z
So OP, what did you wind up doing?
rebusB
CC BY-SA 4.0
2024-09-09T10:12:01.057Z
@rebusB Well, the answer below is fantastic. Exactly the help I needed. It took me a few readthroughs to get it, but the upshot is that the diaphragm from the speakers would amplify the sound of the strings in a manner similar to a microphone, not really the sound you want for a guitar pickup. So I just went with a humbucker.
Michael Atkins-Prescott
<material-selection>
Using old transistor radio speakers as piezo pickups for a cigar box guitar
Michael Atkins-Prescott
# Using old transistor radio speakers as piezo pickups for a cigar box guitar

(Asked by: username_0 on 2024-07-31)

I'm making a cigar box guitar, and I need piezoelectric pickups. You can buy these for around 90 cents on the Internet, but you can also use the speaker from any small electronic device, like a telephone, a clock radio, or even a digital watch with an alarm.

I unfortunately didn't pick up some old telephones when I had the chance, but I do have some old transistor radios. The speakers aren't that big, about 4" in diameter, but they're much bigger than what you'd usually use for piezo pickups.

I am thinking this might work really well or really badly. On the one hand, bigger pickups could make for a meatier, punchier sound, which would be great because cigar box guitars are an amateur project not known for precision. But on the other hand, being bigger could mean they're less sensitive.

Does anyone have any advice on whether this would work or not?

**Tags:** material-selection

> **Comments:**
> **username_1**: Quite obviously, this question belongs to https://electronics.stackexchange.com/. But  "Close" or "Flag" do not give me the option to provide the link :( Someone with enough rights should move the question there, I guess.  
> **username_2**: @username_1 That might be the more logical option, but I see no reason for it being off-topic here: it's a creative project, during which the OP encounters an obstacle, and asks for insight. I would ask the OP to see if Electronics.SE is a site where they would get more constructive/helpful/appropriate feedback, however. If so, let us know, and we can migrate it.  
> **username_1**: @username_2: the whatever OP is building fits to this site, probably. But when we go to the details of radio speaker vs. piezo pickup, then better answers can be gotten there - that is the purpose of that site. That is the only reason I suggested that. They can help better even with the proper interface circuits and stuff. And I made the proposal for moving, exactly because it is a beautiful question.  
> **username_2**: @username_1 Then I misinterpreted your comment, for which I apologize :) I'll wait for a response from the OP before acting on that suggestion, though.  
> **username_3**: @username_1 This question does have feet in both electronics and craft, but there are plenty of projects that do. I think the OP didn't do much ground work before asking so the question is a little broad and could go either way. I tried to answer the craft side by discussing the basics of the devices and how that would effect their use.  
> **username_3**: So OP, what did you wind up doing?  
> **username_0**: @username_3 Well, the answer below is fantastic. Exactly the help I needed. It took me a few readthroughs to get it, but the upshot is that the diaphragm from the speakers would amplify the sound of the strings in a manner similar to a microphone, not really the sound you want for a guitar pickup. So I just went with a humbucker.  

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## 1 answers

### Answer by username_3 on 2024-07-31. Score: 3

This is an apples and oranges situation. Piezo based pickups and the speakers from a portable radio operate on entirely different electronic phenomena so cannot be compared based on their sizes. Piezoelectric materials generate voltages directly based on force applied to them. The coils in speakers react to/generate voltages based on moving magnetic fields. Old telephone voice pickups use a third method that has a base voltage which a carbon granule pickup then modulates based on sound pressure (though they may generate a weak signal on their own) so even more difficult to incorporate. And finally typical guitar pickups also use coils to generate electrical signals, but not from air vibrations pushing a diaphragm pushing the coils but by metal strings vibrating over them.

To answer the question; no, you cannot use an old radio speaker as a piezo pickup because it is not a piezoelectric device. Yes, both can be used to pick up vibrations but piezos do it by directly converting the vibrations of whatever it's attached to into voltages. With the speaker you would need a moving diaphragm or similar to mechanically convert the sounds to something that will move the coil (which the speaker cone can do). You would basically be turning the speaker into a microphone. The latter might be interesting in the way one incorporates the speaker into the sound box of the guitar. It may also be possible to turn the speaker coils into a crude electric guitar style pickup and lose the speaker diaphragm entirely.

Even within the piezo pickup community there are debates on whether they sound any good or not. So the only way the bigger question here can be answered, whether your cigar box guitar will sound better with a piezo or a speaker/microphone pickup, is through experimentation. You would have to try the different things to see which sounds more like what you want. A good start would be learning how the different electronic devices work on a fundamental level so you can use them effectively when designing your instrument.


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