do it yourself following each step below.

step 1: plastic lid preparation

• Choose a plastic lid with a diameter about 1cm bigger than piezoeletric’s diameter. In our video we used a 1″ piezo (25mm)

• With a ruler mark the center of the plastic piece

• Make a hole with the drilling machine and the hole saw. (The hole saw diameter should be a bit smaller than piezoelectric diameter)

• On the side of the plastic lid make a hole with the drill. It’s where the mic cable will pass through.

step 2: copper foil

We will use the copper to protect the hydrophone from electro-magnetic interference.

• Measure the plastic lid height

• Cut the copper foil as a strip with the same height.

• Take the copper strip and internally cover the lid.

• Fix the copper ring with electrical tape

• With scissors cut a hole on the side of the ring Note: it exist a self-adhesive copper foil which could be better for this use (and easier to work with)

step 3: piezo and cable soldering

• Position the piezo centered outside of the lid. The terminals must be seen inside the hole.

• Fix it with electric tape. It will be removed on step 5.

• Before soldering put 2″of thermofit on both sides of the cable.

• Pass the mic cable through the lid and copper holes and solder it on piezo’s terminals : ground on the external part, positive on the internal part of the piezo.

• Solder the 1/4″mono jack plug on the other side of the cable.

• After soldering, reposition the thermofit and get it hot with the lighter.
  Note: it would be possible to use a stereo cable to have probably better shielding. You should then connect ground to the copper foil, positive on the center and negative on the external part of the piezo.

step 4: silicon and iron washers

• Fill half of the lid with silicon.

• Put 2 iron washers inside it. (In order to give some weight to the hydrophone)

• Fill the rest of the lid with silicon.

• Cut a copper foil circle, with the same diameter as the lid.

• Put the copper circle on the top of the silicon, so it will get glued._ Wait until the silicon dries (about 30 minutes)
  Note: you could put some weight on top of the copper foil, so it will get straighter.

step 5: rubber coating

• Carefully remove the electric tape from the piezo.

• Dip the lid in the rubber coating can and take it out very slowly.

• Let it dry for around 30 minutes and repeat this step 2 or 3 times.

• For a uniform rubber layer, you can turn the lid upside down while drying

step 6: Listening

• Try your hydrophone and share your recording

• Enjoy !!

TUTORIAL DONE by Sara Lana & Félix Blume

Other nice hydrophone tutorials where we learned to construct ours:

• Phase 57 give a very similar way of building a contact microphone, shield as ours, and I guess that could easily be used as a hydrophone
  

• Zach Poff give a step by step building of a contact mic in a very easy way. With an interesting list of other places to buy some contact mic online (at the bottom of the page)
  

• John Grzinich share here a nice way to build a DIY hydrophone

• Guillaume Leguen

• Locus Sonus – Grégoire Lauvin

• David Dunn

• LOM contact microphone and interesting things about piezo

• Tim Prebble about contact microphone
  
  

If you want to buy some, here are a few links :

• Aquarian is one of the famous constructor of very good and cheap hydrophones, already very famous
  

• Dolphin Ear is doing very good hydrophones too (a bit more expensive)
  

• Cold Gold has a lot of different models of contact mic and hydrophone, at very good prices (including some piezo and copper foil for DIY mic)
  

• Jez Riley French is doing and selling a few models of contact and hydrophone since a long time now (at a good price too)
  

• Crank Sturgeon sells different models of contact mic (some are waterproof) done by himself

• Monkey Sound is doing and selling a few nice models too

• Geophone by LOM Audio. It is not an hydrophone, but it’s a very nice tool for contact recording

• Ambient sells ones of the best hydrophones, but with a much higher price
  
  
  
  

Missing a link to a nice DIY tutorial or another nice way of buying an hydrophone? Contact us!

https://saralana.xyz/about & https://felixblume.com/contact