Trying to find the name of a device

[Consul]

A few more tidbits turned up in research.

The TalkBox uses a compression driver to send sound down a flexible tube, which makes sense really, as that's sort-of what compression drivers are designed for to begin with. I found a cheap one with a good frequency range at Parts Express:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-097

Some of the comments talk about using them for TalkBoxes with mixed results. They're cheap enough for playing around, though.

I get the impression that the Sonovox was not made with compression drivers, though. I found one reference, somewhere, I can't remember where, that the Sonovox was made with speakers that replaced the paper cone with some kind of thin metal sheet/plate, which would then be held up to the skin of the neck. That's entirely feasible, I suppose. It might not be too hard to mod a cheap speaker in such a fashion and see what happens.

The SoundBug idea is a good one, and I'll probably pick a pair of those up eventually for feeding sine wave sweeps into large structures (like a water tank, for example) for gathering odd and interesting impulse responses. For now, though, I have a very small amount of cash, so I have to stick with what's in the junk box or what I can get given to me.

 

[zebra50]

Darren,

The soundbugs are good fun paired with a PZM type mic - I went through a phase of using these on nearly every session to find unique plate-reverb-like sounds - strapped to widows, metal shelving, rack units, old medical equipment.

About as much battery-operated joy as you could wish for!

Stewart

 

[SSLtech]

If you're going to build a talkbox, don't fart around with under-sized compression drivers. -A 25-30-Watt driver is what you probably want. -It should give you a "whack" in the back of the throat whenever you pluck a string/play a note... and stage rumble should tickle your epiglotis... -Feels wierd, and not what the sonovox does at all, but it's the different nature of the beasts.

Takes a little getting used to, but if you try and use an undersized driver, you'll never be able to use it live, and hearing/feeling what you're doing on a loud stage is completely different. -There's a lot of bone-conduction with a properly-sized talkbox also.

Frampton's obvous tunes get played instinctively when you try one, also the figures from "livin' on a prayer" by Bon-Jovi and "Bosser huit heures" by Trust also tend to naturally spill out... -can't stop it, really!

Keith

 

[Consul]

Actually, I want to build a Sonovox, which apparently involves replacing the paper cones of small speakers with some flat sheet metal. My reasoning is that a Sonovox is more likely to be buildable from surplus junk lying around.

 

[SSLtech]

The Sonovox is -in essence- just a limited-travel linear motor. When I was about seventeen I had an electric razor, -the type with the reciprocating blades behind a curved foil... -it was a Braun, but I forget the model name. -Anyhow, I discovered that it worked perfectly as an 'artificial larynx'; -if you held it up to the side to the side of your 'adams-apple' and switched it on when you wanted to make sounds, then shaped them with the mouth... everything worked exactly as the Sonovox does... -It was like a one-note sonovox of sorts.

Using speakers... well, there's more to it than just 'removing the paper cones'. A speaker is a linear motor right enough- but keeping the motion linear is the combined job of the front suspension (around the outer edge of the cone) and the rear suspension (the axially-corrugated disc around the leading edge of voice coil.

The rear suspension aligns and centers the coil in the gap, but the coil can 'twist' and 'bind' in the gap, scraping and scratching at the end furthest from the suspension, balking and catching, unless it is held parallel to -and equidistant from- the sides of gap. That is accomplished by the front suspension... -ask anyone who's done a few speaker re-cone jobs. -If you pull off the paper, you then have to engineer some way of re-aligning the coil and KEEPING it there. -Better by far would be a dual-spider loudspeaker motor (if you can find one!), but to fully appreciate what I'm describing, best to try building a Sonovox with a 'sacrificial' speaker... -just don't expect it to work properly, or for very long, if and when the coil scrapes in the gap.

The challenge is to keep the coil moving in a single, linear, piston-like motion, with NO twisting.

Keith

 

[Consul]

That sounds basically like an audio-rate solenoid. I'll have to play around and see what I can come up with.

I can see where a Talkbox is easier to build, as it's a compression driver, a box, and some tubing, essentially (also an amp, I suppose, but I wouldn't really need to build one of those). Compression drivers powerful enough and of the right frequency range are pretty darned expensive, though.

 

[Consul]

Compression drivers powerful enough and of the right frequency range are pretty darned expensive, though.

Okay, maybe not:

http://mcmelectronics.com/product/DISTRIBUTED-BY-MCM-3820-/54-255

I ran into this one doing a search for DIY talkboxes.

 

[SSLtech]

That looks fine. Comfortable power rating, and easy mounting. Forget frequency response, over-rate and under-drive and you can get away with a lot more than the quoted numbers, which are after all quoted for efficient horn-loading. We're not doing that here.

As regards solenoids, they don't usually have a sufficiently comprehensive suspension, and they frequently make contact at the sides. -In addition, they're "pull-only" devices, which attract at either polarity. Linear motors are "Push-Pull" devices which repel at one polarity, and attract at the other... so there's quite a difference or two which you may not have considered.

Keith

 

[Consul]

Yeah, it's looking like a talkbox would be the easier build, in the end. I guess the put-off for me has always been the fact that it's billed as being purely a guitar effect. I need to keep in mind that there really is no such thing.

Really, I'm interested more than anything in choir-ohh-ahh-like effects, using a base timbre from a synth. I never really liked vocoders for that because they sound too "electronic", if that makes sense. That's why seeing the Sonovox was a real eye-opener. I do now think the Talkbox would also get me there, though.

 

[SSLtech]

I think that a short "rod" added to a driver voice coil, and suspended near the operator end in a self-centering suspension, with a comfortably-blunt 'ball' or somesuch at the end of the rod and the handle connected ONLY to the non-motive part of the motor (preferably with some useful mass, to help efficiently transfer power to the motive part) should work... but making it convineient and "professional-looking" might be a challenge.

Not insurmountable, but I'm glad it's not a task my boss gave me, or anything! 

Keith

 

[Consul]

In all honesty, Keef, I'm having trouble deciphering most of what you just said.  ;D  I think I'll just stick to the Talkbox approach for now. Maybe some further conversations with my physics prof will present some new ideas.

I was surfing around various hardware store websites today, trying to find 1 3/8" x 18 fittings with a (for lack of better word) "nipple" for flexible hose to slip over (that kind-of sawtooth-looking outside that pulls on the inside of the tubing) for an easy-off tube for the driver. I seem to remember seeing something like that before, so I'll keep my eyes open.

 

[Consul]

Well, as regards the Sonovox, my physics prof's first idea was to find a dynamic mic sufficiently well-made that I can run it in reverse. I suppose some designs of dynamics would work better than others.

 

[SSLtech]

-If you pull the cap off an SM57 you'll basically see a moving-coil reciprocating linear motor...

...but the suspension is the diaphragm, and these are invariably light, delicate and vulnerable once exposed.

Perhaps something like a Beyer Dynamic DT100 headphone driver (which VERY closely resembles a dynamic mic, but with a vastly thicker and stronger circle of mylar) would be a rather better candidate. -the 'diaphragm' is a LOT more robust than anything you'll ever find in a microphone.

Keith

 

[Consul]

The idea of a headphone driver did go through my head at some point. I think it's largely expense that drove me to dismiss it for now.

Sonivox Pros: full articulation with no tube stuck in mouth
Sonivox Cons: exotic and hard-to-source/build parts required, no decent documentation available online

Talkbox Pros: Easily available plans, parts are inexpensive and readily available
Talkbox Cons: Tube stuck in mouth makes articulating some sounds difficult

Really, since I'm interested in choir-like sounds rather than in full articulation, I think a Talkbox would be the way to go. Still, I'm going to try to look up the original Sonovox patent to see if I can glean any more information on them.

 

[Consul]

The Ghetto Talkbox:

http://www.youtube.com/watch?v=9EIQxwotn3k

It actually works fairly well, considering the cost and scrounged parts.

 

[SSLtech]

Both suffer from drawbacks.

Neither can distinguish between voiced and unvoiced consonants.

i.e. Neither the Voicebox nor the Sonovox can distinguish between a P (unvoiced) and a B (voiced), nor between an F (unvoiced) and a V (voiced), , nor an S (unvoiced) and a Z (voiced).

Clever vocoders add a noise source which is modulated to match the carrier, and keyed by the upper part of the modulator spectrum... The Sonovox and the talkbox being simpler devices don't have any way to do this, so the performer has to do it.

Other voiced sounds, such as 'Mmm' and 'Nnn' are also tricky with a sonovox/talkbox. -You get the idea what is being voiced, but the brain has to work a lot to do a lot of filling-in or discrimination of ambiguous sounds... Listen to 'Frampton Comes Alive' with this in mind and you'll see what I mean. -Most people don't clearly hear "we're going to have a good time tonight... -good time, good time" in the tune "Do you feel..."

Food for thought, though; Do play and have fun!

Keith

 

[Consul]

This driver came up as a good choice for talkboxes:

http://www.mcmelectronics.com/product/54-050

Not quite as powerful as the other one, but it has a lower frequency range and has been successfully used to make good talkboxes. It has a pretty good price, too.