Contact Mics

Has anybody experience with these mics here: https://hydrophones.blogspot.it/

Yes, pretty good for the money. The contact mics produce good levels of high frequency content, something a lot of others at that price bracket lack.

Here is a sound from the hydrophones (with significant Hi boost, if I remember)

have to agree with that - if you are going field recording go alone.:microphone:

I seconds everyone that has mentioned that as decent preamp is key if you want accurate representation of sound…I’ve also made the mint box preamp Rodrigo mentioned, it works well in my experience for capturing low pitched objects, but didn’t sound great for things like a snare drum.
The Alex rice preamp design is fantastic, and a small 2 person company in Chicago is now manufacturing kits - http://zeppelindesignlabs.com/product/cortado-balanced-piezo-contact-mic/

The kits are super easy…I made one of these on perforated and the compact size of the ZD model and already matched JFETs are well worth 25 dollars in my mind. It DOES require phantom power. ZD also sells a DIY phantom power supply that runs off a 9v and works really well. You can go ultra dork like me and put them all into one tidy box. This system works well for me since I can make numerous different sizes and shapes, and lengths of contact miss and run them through one preamp. The altoids box contains the PP and the circuit wrapped in copper tape is the preamp. Good luck!

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I have some contact mics I’ve made myself and coated in plastic-dip. When I record them into my field recorder, I find using an impedance transformer improves the bottom end considerable (my Tascam doesn’t have a hi-z input). I use a HOSA MIT-129 http://hosatech.com/product/mit-129/

16 posts were split to a new topic: Transducers / Exciter Speaker

I’ve been looking into ears recently and after seeing this video https://youtu.be/Bv6nDi7i-S8?t=667 it convinced me that I need a contact mic. I have a drumkit and when he runs the cymbals through his modular it just sounds too cool.

I use a Radial Engineering PZ-DI for the same reason, I couldn’t believe it first time I plugged my DIY piezo in it, it’s night and day with and without it. http://www.radialeng.com/pzdi.php

They even include a variable high-pass filter for removing the excess of bottom end you’re finding back when matching impedance (it’s really useful), plus the load is variable with a 3 position switch (electromagnetic/standart/piezo), there’s a pad, an LPF and you can lift the ground.

The only downsides is that it needs +48V and it’s pricey at 220€, I know they also make a simpler, cheaper, version (SB-4), but I’m gonna try your solution for when I need to record various piezo at the same time (can’t afford multiple PZ-DIs right now…)

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So you’d be plugging the impedance transformer into the xlr to mini jack adapter and then into your recorder? I think that should work, but it will be rather bulky and you may get a little signal loss from the adapters. It’s not something I’ve tried myself

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Not sure if anyone mentioned this but there are 2 great tricks for getting better sound out of piezos.
First method: solder them to a mono jack in the usual way, then use a DI box. This alters the impedance and provides a good mic-level signal for any mixing desk.

Second method: some piezos have a two-part zinc contact in the middle. If you solder these to a balanced mic cable like this:
small contact = +
big contact = -
copper disc = screen
Stick an xlr on the other end and use any mixing desk or mic pre. Because the signal is sort-of balanced you can get away with very long cables without interference.

Or buy one of Jez’s mics, they sound great. Piezo foil is nice too but you have to get that from the states these days afaik. xgus

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I’ve been interested and n Hanna Hartman recently https://vimeo.com/82784209 partly as I’ve recently realised that my Octatrack actually works really well by plugging my Contact Mics straight into the inputs.

I thought it could be a useful thread to document ideas or techniques useful with contact mics.

Something I always keep is old guitar strings which I tie together and use as an agitator.

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whilst contact mics / piezo elements work fine plugged directly into things, two notes:

  • piezo elements can make REALLY large voltages. so you’re assuming the thing you’re plugging them into is correctly buffered or limited. most of the time: things are. but remember this!
  • in general, I’ve always found piezos sound much better with a simple preamp after them. You get this very mid-dy sound from an unamplified piezo, and even the simplest amp makes a huge. difference. Here’s an explanation of why this is and here’s how simple you can make a totally fine amp
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I have a few of those preamps that are made to fit into guitar bodies…the very cheap ones from china ( god knows what the guitars you’d cut into for these would be like!) i house them in little wooden boxes.

added bonus of battery holder and vol&eq sliders for less than £10-ISH. The results are decently mid fi. I often use the guitar bridge style piezos as well as they come with a tiny jack at the end.

this kind of thing. I go for the ebay-cheap-china- wait a month for it.

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I was wondering if these https://www.contactmicrophones.com/products-bxcm.html would sound better than my JFR ones being buffered. Although I have a Sound Devices Mix Pre D I use with some dpa mics, maybe a jack to xlr converter would improves things.

I do find that they aren’t very full bodied sounding. I know people who swear by the Barcus Berry preamp combo but would like to get the most out of what I have.

Are these your own devices, they look really interesting?

Just watched the hartman video- i dont know her but it struck me as art performance peice…quite captivating visually with all the tubes. Liked the washers on metal rod. I can imagine trying differnt diameters to get the best effect there. Perhaps the subtly of what she was going for wasnt matched by the live sound on the video. strangely short too.

yes …have a small collection of self build peizo intruments


love spings.



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The mic/pre combo @infovore posted is available as the cortado, which seems to sound really great.

The Cold Gold pieces are real inspirational in terms of form – their idea to solder an alligator clip onto the mic yields some incredible results, and their hydrophone is awesome. (a friend has been recording the Hudson River thawing and freezing, and the results are wild).

When I was building contact mics in college, we would get “liquid tape” or “plastidip” and coat the mics so they would be waterproof, and a little more sturdy. The piezo discs are notoriously brittle, so reinforcing them can be helpful, especially if they’re really thin. Some of them are mounted on a thicker brass backing, which is sturdier but still not hard to bend to the breaking point.

My favorite contact transducer EVEERRRR is the Barcus Berry. These things are so incredible. Transparent and very sensitive. Not waterproof, which is a shame, but you can work around that if you want to.

My friend Kaori Suzuki did a recording in the San Francisco Bay of a flagpole in the wind, and it was sticking out of a dock that rose and fell with the water. The chain clicking against the pole made these incredible laser sounds, and the dock scraped and squeaked against the base of the pole. Super beautiful piece.

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I have Sondbox from Leaf Audio, plus some contact mic contraptions I’ve built myself, love that stuff! The soundbox actually works well as a preamp and since it is battery powered it seems to add less noise than other preamps I have (though I need to see if changing the PSU on the Field Kit does improve things).

I have the Crank Sturgeon Two Timer stereo contact mic:

http://www.cranksturgeon.com/PIEZOCRANK.html

I got a stereo 1/8" to dual mono 1/4" adapter and I plug it straight into my Zoom H4n. It sounds amazing! No loss of low end and none of that cheap mid sound. Very low noise too.

I like to put it on cardboard/wooden boxes and fill the boxes with various objects/materials. I’ll pour some salt or rice in there for extra texture. I also just grab stuff from the kitchen I can bang on. Getting a pair of wire brushes was also a great idea. I definitely want to build some cool custom boxes like @Zedkah. (very cool stuff by the way!)

After I record I usually load the files into Ableton via the SD card then then EQ/compress them. Even do some audio quantizing sometimes. Then I send everything out of my Expert Sleepers ES8 through the modular and back into Ableton.

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