building some in-line talk boxes.

[birt]

I have to build some in line talk boxes. i made this test setup with a dual chip ruby driving a salvaged horn driver. the sound was good and really loud and got me a headache when it was going into my mouth (without a tubing that is, i haven't tried with tubing yet because i have no tubing).
will this amp be ok?
i also want to make the mic go into the talkbox. i don't care about keeping the signal balanced because the the mic is allways really close to the pedalboard. so what kind of mic preamp would i need? i'm thinking about something with one fet or so..

i'd also like to know a good source of compression drivers in europe (preferably as close to belgium as possible) because i need to make at least 4 of these things.

thanks,
bert

[mdh]

I made a talkbox when I first started getting into DIY FX. I found that a bridged Ruby was plenty loud for studio purposes (though I didn't experience any pain with the tube in my mouth), but didn't cut it in a band environment. Even when I built an amp with a 10W chip-amp, I still had a hard time being heard over the band. I think other people have had similar experiences, so before you go into production on your 4 boxes, you might want to make sure that the little amp is sufficient in all necessary situations.

[birt]

that's why i'm posting this. i guess the mic is important too. i think it should be as focused as possible (super or hyper cardioid?)
i want this thing to operate from 9V so the bridged ruby was the first thing to try.

is it possible to make the ruby louder? (4 chips?) i really like the sound of it for a talk box and it's a small build. but it also needs to be practical.

[mdh]

is it possible to make the ruby louder? (4 chips?) i really like the sound of it for a talk box and it's a small build. but it also needs to be practical.

You'd probably be better off using a chip amp that can deliver more power, such as one of the TDA20x0 series or something like the LM3886 (no, the second "8" wasn't a stutter). Take a look at the amps on GGG or check out the ssguitar.com forums. The trouble is that if you want more power, you'll almost certainly need an external power supply (or a bigger box), as a 9V battery isn't going to be able to deliver enough current, and certainly wouldn't cut it with any of the chip amps that I mentioned above.

My understanding is that the big rock stars who use talkboxes on stage run them at truly tooth-rattling volumes, and some who use them in the studio use vocoders on stage b/c they just can't handle the volume that's necessary to make a talkbox cut through.

I'm curious how the inline talkboxes on the market (e.g., the Danelectro Free Speech) perform in a stage situation, and how much power the internal amplifier delivers. My inclination, if I were to take a second pass at talkboxes, would be to make the simplest possible passive box, and try powering it with a 30W or so practice amp. I think it's hard to make generalizations about what will work, though, because it's going to depend on how loud your stage environment is and how hot you can get that mic before it wants to feed back.

[Torchy]

The original talkboxes (eg the Golden Throat etc) had to be driven by yourguitar amp, they didnt have one built-in. To get mine audible live, I had to use a cheap Marshall 30W SS practice amp just for the talkbox. Mic selection was crucial, an SM58 wouldnt cut it and I ended up using a ribbon mic nicked off the harpist (mouth-organ-ist!).

Binned it yonks ago as I needed too much aspirins for the headaches. Then I worked out why Frampton et al only did talkbox solos when the band were quiet ... ...

[birt]

i think i'll go for an lm3886 amp then. can the lm3886 be overdriven? (in a good sounding way?)

[mdh]

I think you'd want to get your drive from the preamp (that is, guitar preamp, not mic preamp). Maybe one of the ROG amp sims? Again, I think the ssguitar.com forums are a good place to look for these kinds of projects, but there are various threads around here about putting together an amp sim, maybe a more complete tonestack, and finally a power amp, usually with a view toward making a practice amp. Search and ye shall find.

[Torchy]

The overdriven sound of a talkbox comes from the high sound pressure levels from the compression driver being forced into a small tube. If you put a distortion box before a talkbox it sounds crap.

The ROG sims are no good for this. You want a reasonable 3886 amp, a 35 - 50W compression driver and some tubing from a home-brew shop.

And lots of aspirin, and a good dentist.

[Meanderthal]

 If you can find one of those old grey/green pa speakers like you'd see in an old warehouse or something with the horns that look like steel megaphones y'ed to the driver, bingo, that's the one! Those drivers will pump a hell of a lot of midrange thru a tube... your skull will shake so hard you'll be able to see the ripples inside your eyeballs. Have fun!

[axeman010]

Hi

I had some good success with this many years ago when the band I was in was doing Livin' on a Prayer.

I used a 25W Hi-Fi amp kit from Maplins driving a 4" mid range Hi Fi Speaker. This was all mounted in an approx.
6" X 6" aluminium box (about 3" deep). I sunk the speaker in to the box from the top and then mounted a 4" kitchen funnel
on top of the speaker which connected to a 1/2" diameter pipe. Then taped the pipe up the Mic stand so that it protruded about 1" in front of the Mic. This allows the pipe to go in to your mouth and your lips to be close to the dome of the Mic. Pretty sure we used SM58s at that time.The Unit was driven by a distortion unit and the output from the Mic then went in to the PA.

The thing was loud and tended to rattle yer fillings but was a great sound. A lot of getting the best sound was in the way it was set up with the Mic and learning how to play it. You need a fairly wide diameter of tube to let the sound flow and try to keep it as short & straight as possible from the box to the Mic. I think I got lucky with the choice of speaker.


Hope this helps.

[birt]

great info!

now i know what to do.
lm3886 amp with a buffer in front of it, now to find a good source for the drivers. i've got 3 really old ones but i'm keeping them, so i need to find a supplier in europe. the tests i did were with those old things, great stuff.

[Mark Hammer]

Call me naive, but I'm still unconvinced that powerful amps, compression drivers, and teeth rattling are necessary for voice-box effects.

I think part of what compels all those things is the generally boneheaded and untailored mic/speaker interface.  The mouth is serving as resonant cavity.  Does the mic NEED to be a highball or SM58 pointed at your face to accomplish that?  Not really.  It could just as easily be a small electret capsule fit into a moulded mouthpiece and pointed at the end of a piece of tubing.  Not directly, since the more direct the path from speaker to mic the less influence your mouth shape has over the sound, but a few degrees more directly; say an arc of 60 degrees as opposed to perfectly parallel.  If there was a sort of cup-like formed bracket, it could easily isolate the mic element and tube to be impervious (or much less permeable) to external sounds, and conserve more of the tube content..

Part of the perceived need for teeth-rattling levels is the signal loss occurring over a greater distance of tubing.  So make the physical pathway of the amplified sound shorter.  Why does the unit need to be on the floor?  Also, bandwidth loss is a concern.  Okay, split the damn signal up with active filters so that you keep some bass and lower mids, and mix your voice-modulated upper mids and treble back in with the bass and lower mids.  You'll get the girth, and the articulation of harmonic content without having to push 25W of 200hz content into your mouth.

Does this make sense, or are there crucial things I'm neglecting?

[birt]

well i did think about mounting the driver on a microphone stand and the guy i'm building these for will possibly use very small DPA mics in a condom. but the 3886 is happy with an 18v power supply so it's not a bad thing to have a little more power than when i'd use a ruby amp. and i do know how to set up a mic, i'm a theatre technician/backline tech

i'll look further into bringing the driver closer to the mic tough.