I'm a fan of the Jez Riley French contact mics.
Here's a blog post I did recording some guy wires with them - epic!
Here's Tim Prebble's excellent tutorial on contact mics.
remember to match impedance or you'll lose all of your low end. enjoy.
I use Cold Gold, a few other hand-made ones, and the rubber contact-mic adapter for the Aquarian Audio H2a hydrophone. The C-Ducers sound pretty compelling - high noise floors are common with cheap piezos - but the H2a is a stellar contact mic...provided you can attach its heavy bulk to something effectively. Tim Prebble and others also like the Barcus Berry ...
Here is a nifty preamp circuit that provides a FET buffer and balances the signal, which deals with all the issues you are discussing. The circuit is based on the work of Alex Rice.) You attach the piezo to the circuit with a length of shielded mic cable, then run a mic cable from the circuit to a male XLR. This plugs into your recorder which supplies ...
contact mics are pretty cheap.
I own some cold gold ones as well, but I never use them anymore. Now I roll with my Jez Riley French C series ones.
here's some classic laser stuff I did with them:
I run them through (inexpensive) hosa MIT-129 impedance transformers to get them matched up ...
The piezos used in contact microphones pick physical vibrations from solid surfaces as you can see here, for example: http://vimeo.com/31926631
In that case of ice recording it makes sense to use those, but I don't think (and I hope someone correct me if I am wrong) a contact microphone under water -- in any other state than solid -- won't pick up much ...
Unless you are recording in a very controlled environment, I would recommend a contact mic (which is, ultimately, a better-sounding stethoscope). A standard capsule-based mic will likely generate too much noise (or pick up noise from the surrounding area) because you'll need to turn it up significantly to pick up a pulse.
Check these out: http://www.c-ducer....
As far as I'm aware, some hydrophones are actually made with contact mics (or piezo transducers) sealed inside a protective housing - so I think your logic is sound.
Actually, Jez Riley French makes some and it seems from his wording that that's how he makes his: http://hydrophones.blogspot.co.uk/2009/04/hydrophones-by-jrf.html
Most contact mic recordings I've made (or heard) have very little information, if any, going on at 18kHz. Attached to many materials like metal, wood, or glass, you'd be lucky to get a ton of information above 5kHz in a recording.
If you are looking at doing some extreme pitch shifting, you are better off using a high-frequency response condenser mic, or a ...
In response to Colin, I too am curious about the stereo Trance Audio rig, so I wrote them.
They responded with the following specs:
The stereo Inducer is a custom-built specially designed low-noise high-definition stereo system that's aimed towards sound designers. The Inducer runs 2 Acoustic Lens transducers, the heart of the system. The Lenses, which ...
Though I don't own any, Barcus Berry contact mics sound awesome. I use the Aquarian Audio H2a contact mic adapter. I also bought a contact mic a couple of years back from these guys. Don't think they sell their mics anymore, but there is a useful guide on how to build your own.
I'm also looking forward to hearing more about the new Trance Audio stereo set ...
They can definitely be tricky to get usable material out of but with some experimentation can yield some amazing source.
I have a bunch of various contact mics from these guys:
They make an interesting and affordable selection of various transducers. They also sell some of the bare parts for making your own ...
The key to a good contact mic lies more in the preamp than in the transducer itself. Contact mics will inherently pick up sound from a very unique perspective, but you need preamp circuitry that will not only keep noise low but will also provide the necessary impedance to match the high load of the mic itself. Because impedance is a frequency-dependent ...
Have you looked into condenser microphones? Instead of the dynamic mics, condensers are used for more intimate sound recordings. Additional, the Sanken brand makes some microphones for such needs. "Sanken [makes a mic] called the MO-64, which is capable of recording the heartbeat of a snail."
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You will need a wireless lav mic.
Two manufacturers of such systems at entry level prices (as wireless can be very expensive) are Sennheiser and Shure (there are other manufacturers, of course).
Now, one issue is to find the way to hide the mic under your Mark Twain clothes. You might need some training, find appropriate accessories (like gaffer tape or ...
That's a great question. I think your explanation of the problem would be good to share with customers, educating them rather than providing them with a meaningless spec. Then maybe link to a couple of sample recordings of common sources recorded with your mic attached to some likely surfaces.
It really is an interesting problem. Wonder what Shure, Crown, ...
I can vouch for JrF: http://hydrophones.blogspot.se/2011/05/c-series-pro-contact-microphones-new.html
I never leave home without them. Using an H4n.
They are used by BBC, which according to me is a good reference.
Jez riley French is an established name in hydrophones and also contact mics, especially for people who find Trance's offering "on the expensive side".
Also see this: Can you suggest a good contact mic for sound design? (average cost of proposal would be much appreciated)
You also could use a SM58 or any another microphone, put a condom over it, make a lot of gaffertape around it until it's dense and hold it in the water. (I would suggest to take your cheapest microphone :-).
A hydrophone is a specialized microphone for the use in the water. For example, if you drive thousands of miles to the north pole and want to record ...