what is piezo

[Lewis]

iv looked for previous threads and have'nt learnt anything, so i want a straight anwser, so i can fully understand its use. thanks.

 

[FunkyMan]

I think that Piezo emulate electro-acoustic bass sound! Not sure.. wait for official answer!

 

[ThirdthumB]

It's a property of a material, usually a crystal, that converts physical stress into an electric potential. This material is located where the string is in contact with the saddle. So if you play a note, then stresses will be created in the string, and this will be picked up by the piezo.

 

[herb vibes]

like a pick up in the bridge. sounds excellent but expensive!

 

[Florin]

It's like the pickup from the turntable. It picks the string vibration, not an electro magnetic wave. The sound is very acoustic- like.

 

[golem]

It's a property of a material, usually a crystal, that converts physical stress into an electric potential. This material is located where the string is in contact with the saddle. So if you play a note, then stresses will be created in the string, and this will be picked up by the piezo.

`

Which means that the piezo PU's we use for bass are, by their components and by their function, essentially contact mic's. BTW, you can buy a piezo disc, with leads, from Radio Shack and mess around with it.

`

 

[ThirdthumB]

It's like the pickup from the turntable. It picks the string vibration, not an electro magnetic wave.

Sorry, it's not the same. A piezo doesn't move at all, but it "feels" pressure fluctuations of the strings resting on the piezo. A pickup of a turntable gets its signal from a magnet (attached to the needle) that moves in an alternating way in a coil: physical movement is required, unlike witch a piezo.

P.S. with turntable, you have a moving magnet (MM) and moving coil (MC) systems.

 

[FunkyMan]

By the way, Basses that are equipped with piezo always have it activated? or you can turn off?

 

[SurrenderMonkey]

It's still electronically amplified, as the current produced by the sensors is minute. So yeah, you can turn it off with a switch usually Piezos basically generate electricity when vibrating, same effect as in digital watches.

 

[Kris]

By the way, Basses that are equipped with piezo always have it activated? or you can turn off?

There are volume and tone pots for the piezo...

 

[golem]

By the way, Basses that are equipped with piezo always have it activated? or you can turn off?

`

I have several piezo+magnetic basses, various brands, and I've tried out others that did not go home with me. I have never seen one where you can't turn off the piezo.

Now that I think of it, even on a piezo-only bass, you can still turn it off.

Yup, don't worry about it.

`

 

[Florin]

It's like the pickup from the turntable. It picks the string vibration, not an electro magnetic wave.

Sorry, it's not the same. A piezo doesn't move at all, but it "feels" pressure fluctuations of the strings resting on the piezo. A pickup of a turntable gets its signal from a magnet (attached to the needle) that moves in an alternating way in a coil: physical movement is required, unlike witch a piezo.

P.S. with turntable, you have a moving magnet (MM) and moving coil (MC) systems.

Actually most of the turntable needles are piezo ;-) That's where I first heard of this stuff looong time ago.

 

[Kris]

Both my MM and MC have diamond tips...

 

[Florin]

We are not talking about the tips here. the piezo crystal is located lower.

 

[ThirdthumB]

It's like the pickup from the turntable. It picks the string vibration, not an electro magnetic wave.

Sorry, it's not the same. A piezo doesn't move at all, but it "feels" pressure fluctuations of the strings resting on the piezo. A pickup of a turntable gets its signal from a magnet (attached to the needle) that moves in an alternating way in a coil: physical movement is required, unlike witch a piezo.

P.S. with turntable, you have a moving magnet (MM) and moving coil (MC) systems.

Actually most of the turntable needles are piezo ;-) That's where I first heard of this stuff looong time ago.

A bit off topic................anyway, I checked Wikipedia, and you're partially right. The pre 50's phonograph used piezo indeed, and is used in the same way as with piezo on basses. These days, piezo is not used anymore, and the needle is usually made from diamond. And the principal is comparable to that of speakers. I learned something.

 

[Kris]

We are not talking about the tips here. the piezo crystal is located lower.

Well I really don't know anything about my dad's stereo, I just listen to it

 

[Florin]

Please, don't insult me! I still see the CD as a wonder of the modern world )

 

[Kris]

Please, don't insult me! I still see the CD as a wonder of the modern world )

CD's are nice, but CD players are only now living up to the original promise! I still prefer LP's, just such a warm and big sound

 

[Escobon]

It's a property of a material, usually a crystal, that converts physical stress into an electric potential. This material is located where the string is in contact with the saddle. So if you play a note, then stresses will be created in the string, and this will be picked up by the piezo.

True. I can add that most piezoelectric transducers are ceramic, which has a crystalline lattice structure. Physical stress on this element causes changes in conductivity. This can be sensed when a potential is applied to the piezo element. Changes in conductivity, and therefore current, can then be sensed and amplified by passive (reactive), or active circuitry.

Phonograph cartridges (early on) were indeed piezoelectric, but later became moving coil cartridges (yes, with diamond styli) which are inductive. This is a completely different story.

FWIW,

O

 

[Shoewreck]

By the way, Basses that are equipped with piezo always have it activated? or you can turn off?

Piezo pickups need to be activated in order to take advantage of their full sound with deep smooth lows and clear bright highs. Amplifier and cable impedance degrade piezo pickup signal.