Hydrophones

I’ve seen many references to people using hydrophones here on the forum.
I also use hydrophones for underwater field recording.
Until now i’ve always done this with DIY hydrophones.
I’ve made several mostly with piezo discs and also one with a electret mic in oil.
The results have been mixed. Sometimes it works great and sometimes it’s hard to get any sound at all.

Now i’m interested in buying a hydrophone for use with my Sony D100 field recorder.
I’ve seen this: http://www.aquarianaudio.com/h2a-hydrophone.html

I’m curious what other peoples experiences are and other options.

1 Like

OK sounds great, what’s the cable length you use?
9 meters seems a bit long and 3 a bit short maybe in some situations.

1 Like

I’ve got the H2A hydrophone! Works great, very easy and low-maintenance. Good sound as well. I’ve used it in a river, and also dropped it off a ocean-side jetty.

I opted for the 9m version, just so I give myself some leeway in terms of depth and distance.

What kind of cable is it? Is it a thick XLR like cable or more thin like a headphone cable?

I’ve read or was told that the earliest hydrophones were simply normal microphones wrapped in condoms. Can anyone else confirm this?

2 Likes

i don;t know if this is true but i tried something similar. I needed some underwater fx and i wrapped a SM58 in plastic bags and put it halfway into a bucket. It works. But for real hydrophones it’s important not to have an air layer between the pickup and the water. Water actually travels better in water then in air.
That’s also the reason humans hear very badly underwater. Because there is air in our ear.

1 Like

can’t comment on their effectiveness firsthand, but here in Richmond there was a group that featured performers submerging their heads in water-filled fishtanks and screaming through microphones prepared exactly that way. sounded pretty cool!

2 Likes

I had once asked Daniel Menche about field recordings and hydrophones and he sent me to Lawrence English, who I’m pretty sure recommended Aquarian Audio’s products for underwater field recordings.

I’m especially interested in the possibility of using hydrophones to record through layers of ice and freezing water during Chicago winters, and it’s likely that I’ll end up with one of these at some point.

3 Likes

At present I have JrF hydrophones, but I have more experience with Cold Gold (https://www.contactmicrophones.com) stuff, and can highly recommend it for the price.

Here’s a (post-process) recording I made of small melting ice plates with a Cold Gold stereo pair for reference: https://soundcloud.com/netrethowan/tiny-ice-plates-16-april-2016

These are the only hydrophones with which I have any experience.

1 Like

We have an Aquarian audio hydrophone, I don’t recall the model. very well built, sounds great, much better than the one Anne DIY’d in oil and a film roll canister.

1 Like

I think the Aquarian is excellent, particularly for the money. I also have a B&K one which is heavy duty and probably better if I ever get to record deeper sea creatures but the Aquarian is well built and sounds good.

I’ve ordered an Aquarian Audio Hydrophone from pinknoise in the UK. I’m really curious how it compares to my DIY hydrophones.

Anyone had any experience with these http://ambient.de/en/product/asf-2-hydrophone/ and how they compare to the h2a?

I don’t have experience with the ambient one. But if they deliver what the specifications are i think it’s better then the H2a.
I’ve been using the h2a a few times couple of months. The pro side: It’s got a really huge signal level and low noise. Much better then my previous diy hydrophones. The downside is there a really steep cutoff of high frequencies above 5kHz or so. Some of my Diy hydrophones did better. So recordings tend to sound very dull.

The Ambient one says it delivers 70Hz to 20kHz.

[EDIT]
I’ve done some new recordings and looked at the spectrograms and analyzed some more.
The roll of from the aquarians not so low. Actually i found sounds recorded up to and above 40khz. There seems to be a really strong emphasis on sounds around 1 KHz or so. So it tends to sound very mid sounding.
All sounds above about 6 KHz are much softer in th recording. But when i filter out all the lower frequencies there actually is still a lot recorded on the high frequencies. I think it’s nice to use quite extreme EQ on the recording results.

2 Likes

Yes, from my experience I end up buying the slightly more affordable version then end up getting what I should have in the first place. Dolphin Ear are the other contenders http://www.dolphinear.com/pro.html

Inspired by this post on fish vocalizations (A Catalog of River-Dwellers) and my recent acquisition of a Mixpre 10 II, I picked up an Aquarian H2a XLR. It arrived today so I put it in my bag and set off for the nearest lake in hopes of capturing some fish talk.

Now this lake is known to be the domain of a thuggish gang of bluegill who will attack interlopers on sight. I have personally been bitten by them many times while swimming! As expected, they bird-dogged me the whole way down the dock. However, upon setting up my rig and donning the phones, I heard nary a fishy blerp. They simply floated there, looking at me as if to say “what’s my motivation?”.

Fortunately I’d had the foresight to bring with me a motivator in the form of some crunchy dried cheese bits. The introduction of cheese to the situation didn’t prompt any vocalizations that I can distinguish, but it did make for some entertaining fishy mastication sounds.


I am getting a bit more self noise than I would like coming from this hydrophone. I’d say the dynamic range is there as loud sounds (not in this clip) are reproduced well, but sufficient gain for quiet sounds brings up the hiss. Is there a better device to capture the softer sounds of the underwater world, or do I just have to live with the noise?

7 Likes

So cool! I was really hoping I’d find bluegills in the Marie Fish book, but I guess that family isn’t found in Rhode Island where she was doing her studies. I hear that fish crunching away though, amazing! I love it.

I have had the same issues with my little bit of hydrophone experimentation. I was asking a friend who knows way more about this stuff than I do and he suggested a small phantom-powered preamp as close to the microphone as possible would be the way to go. The shorter the distance between the preamp and the mic, the more amplification you can get out of the piezo disk without as much noise. (As I understood it anyway.)

I’d like to experiment with this, he said he could recommend a simple preamp circuit to build so I can pass that along at least – he’s on this forum too but I don’t know his username haha, so maybe he’ll chime in.

1 Like

The XLR version of this mic (which I’m using) is 48V phantom powered. I assume the amplifier is in the XLR rather than the head though. I have to think that there are limitations in sensitivity in a contact type mic vs something with a light diaphragm.
I did pick up the contact mic accessory for this hydrophone and recorded some with it today. I should have some samples and comments on that soon. I think I got some good percussive sounds out of a swim step and a few boats.

1 Like

Nice. The wall I ran into was trying to record a mic frozen into a block of ice. Except for the beginning and end it was mostly noise floor. On the other hand Collin Olan made a fantastic recording in 2002: https://www.discogs.com/Collin-Olan-Rec01/release/228323 but I don’t know why he was able to get such better amplification! (it’s an amazing recording)

5 Likes

Yeah! I love that ice and snow stuff. The first time I heard something like that was some years ago. I was driving alone at night from Portland to Seattle listening to college radio. They were playing a whole album (someone from Scandinavia I think) which had a lot of highly amplified snowflakes landing and ice creaks. As I drove further, the radio signal gradually degraded in the most beautiful way. I had a bit of a moment then, still remember it.
Here are some relevant recordings, some of which are using hydrophones or contact mics. http://www.gruenrekorder.de/?page_id=107 Several of these recordists are getting the small sounds of snow and ice very loud without much noise (with unsophisticated equipment). I’ve much to learn it seems.

4 Likes