#21

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Here’s a pic of one of my corked speakers. I tend to drive it using a 20-50 watt amp.

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#22

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I have a pair of Vidsonix Ghost transducers that I added a pair of strong magnets to - so they could clamp on to large metal surfaces. Good fun!

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#23

I too want to explore this, and have been designing a modular instrument of my own that will use transducers and strings inside its own case to turn it into something of an acoustic feeling instrument :slight_smile: I want to use contact mics and piezos as well as spring reverb to be able to create feedback loops, as well as having a clean output from the strings themselves that can be mixed with the synth signal.

My question about transducers: what are people using to drive them? Would it be enough to use a VCA or output module straight to them?

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#24

I have this question too!

When I was first experimenting with transducers, I used a Behringer bass amp that I had lying around, cut the wires that ran to the speaker, added alligator clips, and used that. That drove bass shakers & cymbals very well.

With guitars, I’ve mostly used battery-powered mini amps. The Dean Markley GT 1000’s headphone output can pretty easily be turned into an external speaker output by cutting a trace or two and replacing a resistor with a jumper, and that works very well if you’re going guitar pickup -> amp -> transducer (which you aren’t). The Marshall MS-2 contains a really similar-looking circuit (they’re probably both built by the same factory somewhere) but different voicing that I didn’t like as much for feedback.

For the Vulneraries albums I’ve been using a Blackstar Fly 3 with a 1/4" speaker output I added following these instructions: http://diy-fever.com/amps/blackstar-fly-3-review-mods/. It can provide more than enough power for our purposes, the batteries seem to last a nice long time, and it has a pretty flat frequency response compared to other mini amps.

But I’d love to find a solution that was a little more compact, flatter, or both, and if it was also a Eurorack module… hell yeah. Pulp Logic makes/has made a few different “driver” tiles, but I don’t have a case with 1U rows, and I think I’ve heard they’re not especially high-power.

(If an admin wants to move this into a transducer thread at this point, I’d understand.)

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#25

It really depends on the transducer and how hard you want to drive it. If you want to drive an exciter or small speaker at audio rate then a small audio amplifier will work well. I often use the little 12V class-T (Tripath marketing for a class-D) amp boards that you can get on ebay for around $10. They are stereo, small, efficient and sound alright.

If you want something DC coupled the Koma Field Kit looks awesome.

If you are working with real small currents I have a DRV 1U Tile that will deliver a bit more than 50mA into a load. I use it to drive small speakers, exciters, meter movements, tiny motors etc… It works well with loads that have higher impedances than a typical 8 Ohm speaker since it will current limit on a pretty low voltage. HiWave was making a 32 Ohm exciter but I think it is no longer available.

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#26

Thank you! Going to try out the Class-T amp board for this project. I think this could be very useful for people wanting to experiment with creating their own speakers, back on topic, too!

@synthetivv, I might try using something like the Blackstar for when/if I eventually make a set of portable “acoustic” speakers for electronic instruments a la Ondes. It sounds like a workable solution.

LOVE Vulneries by the way, I’ve felt very inspired by it and want to try something similar with my resonant case when it’s finished and a Celtic bouzouki!

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#27

Do you place these snugly against the objects or just up next to them? My intuition tells me that if the cork loses contact with the object within the cycle, it would produce artifacts similar to clipping but I’d love to be completely wrong on that front.

#28

Yep, more often than not I would make sure the cork is in consistent contact with the surface/object - which is easier to maintain if the signal is relatively stable or un-complex (i.e. set or drifting frequency; pure/sine waves).

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#29

I’ve had a long-time infatuation with Stig Carlsson’s speaker designs, in particular the Sonab OA-5. Perhaps not too exotic if you are from Sweden. They were quite popular there.

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Whilst they form a stereo pair, instead of directing sound toward a focused listening point they were designed to instead throw sound all around the space omnidirectionally.

Some of his other designs:

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#30

It’s worth noting that his OD-11 design has been reissued by Teenage Engineering!

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#31

Ooh, I love that! Right up my alley. :ok_hand::upside_down_face:

#32

Look Mum No Computer featured this 60’s Dax-Éko RA40 spring reverb hifi speaker:


Pretty interesting reverb sound, to me it sounds different from the spring reverbs in guitar amps and looks very easy to DIY a clone of.
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#33

i’d like to have this one:

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#34

I encourage checking out the work of Leslie Flanagan, who performs on custom speakers she builds.

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#35

Hey so I’m going to try and build a Martenot “Métallique” Speaker (basically copying the Eowave Metalik form factor)

I’m following William Piotrowski’s blog on the subject:

I plan to use the t.amp PM40C to connect to a BMS 4538-8 driver that’ll be attached to Thomann Wind Gong 55 (22").
Supposedly this will work right?
My audio engineering skills are quite lacking, but I assume the amp generating 40Watts at 8 ohm will be enough to run with the BMS driver (Power rating: 60 Watt RMS at 8 Ohm Impendance).

Would appreciate a bit of help if anyone knows about this kind of stuff.

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