Locus Sonus


This revision is from 2018/07/31 16:07.

Professional or marine biology hydrophones are expensive and not quite easy to find. But it is possible to build one using piezo disk for a reasonable price and with decent quality.

The basics of the presented hydrophone is to use two piezo disk together to reduce noise and increase output level. The circuit provide a balanced output and allow the use of great length of cable. It is entended to be used with a XLR phantom powerd input.

Piezo disk are high impedance devices, and although the hydrophone can be used as they are, a dedicated preamplifier can significantly inprove sound quality and improve low frequency responce.

The hydrophones presentent here are inspired by the work of sound artist David Dunn who extensively worked with piezos.

The preamplifier electronic circuit is originaly from Alex Rice, now offline, and provided by sound artist and Locus Sonus Soundmap collaborator Zach Poff.

An aquatic live stream from Zack Poff is present on the Soundmap, or here right from the server.

Our first take at hydrophone was a two disk balanced circuit encased between two thick piece of laser cuted plexiglass.

But it was not that good, due to the thickness of the plexyglass.

The second take was better. It use a David Dunn's tow chained piezo circuit, glued at the bottom of a thuna can. The used can was already coated witch provide electric isolation from the piezo disk to the can. The can is used as a shield an solder to the ground wire of the XLR plug.

You will need a thuna can (or of other food, the fish do not matter, but the size do), and two piezo disk.

Using epoxy, glue the piezo at the bottom of the can. The piezo brass part of the piezo must be cuted to fit in. Be carefull that the brass part of each piezo do not touch one another.

Last changed 2018/08/03 17:09