Which piezo works best in DIY edrums with Megadrum?

[glenn.szymanski]

I'm going to retrofit 3 of my mesh head drums.

Which piezo have people that the most success with Megadrum?

As far as not being too hot and works best for positional sensing? Sends the correct wave type.

[airflamesred]

Answers will vary for sure. Many other things to consider, placement, glue, position etc.

[glenn.szymanski]

Thanks for replying.

This is a Roland PD-120 pad. I just ordered 3 replacement foam cones. The original ones felt very "squishy" when I took off the original mesh head.

I took some photos of the center and rim piezos, but the max file size to upload on here is 256 kb

the center piezo seems to be 1 and 1/16 of an inch

the rim piezo seems to be 1 and 3/8 inches

I'll try private messaging you

[ignotus]

Sounds like it has a 27 mm piezo for the head and a 35 mm for the rim. The safest bet are Murata brand piezos. Whatever you do, just avoid cheap Chinese ones.

[glenn.szymanski]

Sounds like it has a 27 mm piezo for the head and a 35 mm for the rim. The safest bet are Murata brand piezos. Whatever you do, just avoid cheap Chinese ones.

Thank you for the information. How do I tell if they are the cheap Chinese ones?

Will those piezos work on Megadrum without any kind of voltage divider? Will they produce the positive wave needed for positional sensing?

I went to the Murata website. Looks like they offer 2 different models. The 7BB and the 7NB. Difference being brass or nickel. But then there a bunch of different part numbers with different resonant frequencies and resistances.

https://www.murata.com/en-us/products/sound/diaphragm

[ignotus]

You want the brass ones. As for resonant frequency, I don't really know what Roland and others use, but the piezos I buy are 4500 kHz and work fine. My uneducated guess is that the resonant frequency doesn't matter that much and is more relevant when using the piezo as a buzzer, not a sensor.

By cheap Chinese, I mean the piezos they sell on Aliexpress and ebay and don't state the brand nor any technical details about them beyond their diameter.

If you have the positional sensing board, you don't have to worry about the first half wave polarity - that's what it's for. And if you don't have it, positional sensing will be a struggle anyway. And a voltage divider shouldn't be required either.