Piezos with Cajon


I hope someone can help me with my project. I am attaching 4 piezo disk to the inside surface of a cajon (wooden drum box with string inside). Three in the the front and one on the side.

I am using 10K ohm resistors with the each of the piezo disks.

If I hit the drum on the left side (in front of the left piezo) I still measure a signal from the right side one and the one which is attach in the middle of the front surface.

The problem is: sometimes I get a stronger signal from the piezos which are further from the place I hid the drum.

I wonder, whether there as a good way of tweaking the piezos so they are more sensitive to the hits which are close to them. .

sorry for English, any help appreciated.


This problem is more a mechanical one rather than an electrical one.

You might get improvement by mounting the sensor on some foam so that direct hits are more easy picked up than the vibrations transferred through the outside of the drum.

In any case it is the mounting of the sensors that are causing you trouble.

Hello Mike,

yes, you are absolutely right. I have to find an other way…