#16

There must be something in the air. I’ve been recording lately with a guitar & transducer setup that was originally inspired by the Palme (but also by David Tudor’s Rainforest, and sustainer technologies like @oot is using), and @tristan_louth_robins recently posted a nice transducer- & guitar-based piece for the latest Junto.

I’ve used transducers / bass shakers to resonate electric guitar before too, which yields a less Ondes-y sound since, as with @oot’s setup, the resonated instrument isn’t inherently acting as a speaker, so you have the option to completely eliminate the “dry” signal and record or listen to the strings alone.

I also have a cheap electric lap steel that I initially bought to use with transducers as a compact set of sympathetic strings, but so far I’ve been too distracted playing it as a lap steel to use it that way yet. I’ll get around to it eventually.

Oh, and cymbals are amazing too. For the MĂ©tallique diffuser sound.

Out of curiosity, how, uh, “fiddly” is the GR? Do you find you have to place it very carefully and leave it there, or can you get nice results from changing the position while playing? The clip sounds great, by the way – I’d love to hear it in context with the harp. Have you released recordings with this setup?

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#17

Baking trays with water sound really interesting!

The way I use it is usually to place the guitar on a stand and then adjust the GR-1’s stand against it, which is fiddly in the way goosenecks very often are – you turn it and find a sweet spot only for it to immediately slouch that cm or so from that position when you let go. I tend not to touch it once I’ve set it up simply because I always have some other instrument in my hands.

Moving an instrument like a guitar around it as it’s intended does however work really well and while the amplitude is quite different across the string, the same is true with the frequency content of the input signal, as you heard in that clip. I like using it with a compressor as often inputs that are less consonant with the string’s root note is are more interesting.
It does crossfade cleanly between strings (completely different from something like an EBow), sounds very interesting to do with percussion.

Not yet.

1 Like
#18

At my previous job I had the chance to listen to a pair of these Avant Garde horns with 4 stacked subwoofers (6 seen in the first photo here). Can’t remember exactly but I think they collaborated on some sort of audio installation recently as well? The horns sound amazing, but were very tweaky to dial in.

#19

plasma

http://www.swtpc.com/mholley/PopularElectronics/May1968/Flame_Amplification.htm

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#20

Wow, this is a fascinating topic of discussion! and thanks to @synthetivv for mentioning me and getting me involved in the chat. I’m looking forward to checking out some of the links that others have shared. :slight_smile:

Yes, I’m a big fan of transducer/exciters for resonating surfaces. For the past year I’ve also be experimenting with the great DIY approach of ‘corked speakers’. I first came across this in Nicolas Collins’ wonderful book, Handmade Electronic Music many years ago.

All you do is find a decent sized speaker - say 8-10 cm in diameter - and affix a cork (ideally a fat champagne-style cork) to the centre of the cone. I made a few of these by fixing the corks with some hot glue to speakers of varying dimensions. Basically it’s a crude driver, whereby whatever signal/frequency you send through the speaker (depending on the amplitude/signal strength) will cause the cork to move/oscillate in tandem. You’ll get a great result by using pure waves at a frequency anywhere between 10-100 Hz, depending on the speaker, amplifier, etc.

I’ve had some interesting results by placing them in contact with resonant surfaces like baking trays, cymbals and wine glasses (be careful with this one though!) Aside from the resonance factor, you can place objects over the moving cork to create all kinds of rattling, shaking and sibilent sounds (alfoil and crumpled paper are particularly fun).

Best, TLR

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#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 “MĂ©tallique” 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.

5 Likes