Hydrophone Experiments II
I started experimenting with inexpensive DIY hydrophones awhile ago. This update discusses encapsulation, commercial hydrophone elements, and modifying a Primo EM172 capsule for underwater use.
Resources
Hydrophone Experiments
An underwater microphone using a common mic capsule and silicone sealant. It has relatively flat frequency response without the resonant “honk” of the piezo disc used in most DIY hydrophones.
Exploring Ultrasound
Experiments with recording ultrasound bat calls using the built-in mics of the Roland R-05 portable recorder.
Alex Rice Piezo Preamplifier
Alex Rice designed a phantom-powered preamplifier for piezo contact mics and hydrophones. It sounds great but his site is offline. I posted his files and made some changes of my own.
Inductive Pickup Experiments
Use the coil of wire from an old relay to listen to the electromagnetic world of modern machines.
VLF Natural Radio Experiments
“Natural Radio” is the low frequency residue of lightning strikes and space weather. After building a simple preamplifier circuit, you can tune it via the mic input of any recorder.
Low-Noise Binaural Mics (Primo EM172)
How to make wonderful low-noise binaural mics from Primo EM172 capsules for under $20/pair.
Zach’s Recorder Recommendations
An opinionated, annotated list of portable audio recorders, updated occasionally