Hello,
I've recently been dipping my toes into the world of DIY contact mics. I've had decent initial success with a cheap piezo element that I soldered to a T/S jack (so I could use it with different cable lengths into my recorder) and waterproofed with plastic dip for water use, however, the unbalanced signal is subject to a lot of unwanted hum. So I did some digging and found a guy that had "glued" two piezo elements together (crystal side in and facing each other) and used it successfully as a cheap hydrophone with a nice balanced signal, eliminating the hum. He connected the ground wire from each piezo element together and then soldered them to the braided sleeve of the XLR cable. Then he connected the red center wire from one piezo element to the hot pin of the XLR cable and the other red center wire from the other piezo element to the cold.
I tried to do the same by sandwiching two piezo elements together with a thin layer of silicon caulking and have run into some trouble. I'm getting a signal into my recorder when I have the black ground wires of the sandwiched piezo elements soldered to the ground sleeve of the XLR cable and the center wire from just one of the piezo soldered to the hot pin of the XLR cable. But as soon as I touch the center wire from the other piezo element to the cold pin wire of the XLR cable it kills the signal completely. This is my first foray into working with XLR cables so please excuse my ignorance. I've been doing some reading on it and I seem to be missing/misunderstanding at least one key concept here. Any suggestions or insight would be greatly appreciated.
Here is the link to the website I used:
Noise free, balanced piezo microphone - Christian Liljedahl
I've recently been dipping my toes into the world of DIY contact mics. I've had decent initial success with a cheap piezo element that I soldered to a T/S jack (so I could use it with different cable lengths into my recorder) and waterproofed with plastic dip for water use, however, the unbalanced signal is subject to a lot of unwanted hum. So I did some digging and found a guy that had "glued" two piezo elements together (crystal side in and facing each other) and used it successfully as a cheap hydrophone with a nice balanced signal, eliminating the hum. He connected the ground wire from each piezo element together and then soldered them to the braided sleeve of the XLR cable. Then he connected the red center wire from one piezo element to the hot pin of the XLR cable and the other red center wire from the other piezo element to the cold.
I tried to do the same by sandwiching two piezo elements together with a thin layer of silicon caulking and have run into some trouble. I'm getting a signal into my recorder when I have the black ground wires of the sandwiched piezo elements soldered to the ground sleeve of the XLR cable and the center wire from just one of the piezo soldered to the hot pin of the XLR cable. But as soon as I touch the center wire from the other piezo element to the cold pin wire of the XLR cable it kills the signal completely. This is my first foray into working with XLR cables so please excuse my ignorance. I've been doing some reading on it and I seem to be missing/misunderstanding at least one key concept here. Any suggestions or insight would be greatly appreciated.
Here is the link to the website I used:
Noise free, balanced piezo microphone - Christian Liljedahl
Help with DIY Piezo Hydrophone
Aucun commentaire:
Enregistrer un commentaire