DIY Talkbox - trying to decide between 3 drivers

[fallenturtle]

I'm looking to make a talkbox for both guitar and synths on the cheap. I'm planning to use a ****ty practice guitar amp that is either 10-watts or 50-watts (says 50-watts on the back, but online seem to say otherwise, its a Kustom KLA10. If that's not powerful enough I might use my Laney GC30.

I'm trying to decide between three drivers. One is half the price of the other but as a smaller frequency response and I'm wondering if the increase in FR is worth paying more for considering my application.

Miyako DU-60 60-watt - 200Hz~6kHz - $20
https://www.amazon.com/gp/product/B07FJZJ8WK/

Miyako DU-100 100-watt - 150Hz~6kHz - $25
https://www.amazon.com/gp/product/B07FK14Z6W/

MCM 54-050 40-watt RMS/60W Peak - 100Hz~8KHz - $40 (including S&H)
https://www.newark.com/mcm/54-050/compression-horn-driver-40w-rms/dp/39C0599

Thanks.

[Mark Hammer]

A lot of bandwidth is eaten up by the tube itself, and even more is lost to your mouth cavity.  6khz bandwidth is more than enough for the purpose.

I recently resurrected a Danelectro Free Speech pedal I bought some 6 years ago but had never used.  Unlike more conventional talk-boxes, it functions as a pedal, rather than requiring a voice mic feed to a PA system.  It houses a low-wattage amplifier and 3" speaker, with a jack in the back for a pair of electret mics (that come with the unit), and an enclosure shaped to provide a nice snug fit of a hose over the speaker.  The speaker is audible through the hole for the hose.  If you simply plug a guitar into the unit, you can even use it as a low-volume practice amp!  The output of the pedal is whatever the mic capsules detect.  Hit the bypass switch and it's clean guitar going to the amp.

Do talk boxes need to be loud and have wide frequency response?  Not really.  Certainly it is important for the mic to be unobtrusive enough that you can more or less block it from picking up extraneous sound beyond the hose, and the sound level coming from the hose to be louder than the sound of one's moustache brushing against the mic.  But beyond that....

[willienillie]

You want a phenolic diaphragm.  Your Newark link isn't working, but the others mention a Neodymium diaphragm, not sure if they mean the magnet or what.  Anyway, you don't want a metal diaphragm, especially with a cheap SS amp (hey I used a $5 First Act for mine!).  10 watts is plenty.  Your Kustom's "50W" probably refers to power drawn from the wall outlet.

[stallik]

What Mark says - but.
For me, it was the lower frequencies that I was struggling with till I settled on a Monacor driver
https://www.monacor.com/products/pa-technology/speakers-/horn-speakers/low-impedance--/ku-516/
Similar to the second choice on your list. The amp I'm using (for home use only) is a 3 watt, Velleman board. This gives me a volume out of the tube about the same level as my voice. I'm sure that for stage use, you'd need it louder than that so the mic level can be lowered to limit bleed from the rest of the band. 100 watts may be enough to loosen your teeth.

In my case, I can either send the mic signal to the PA or back into my pedalboard and guitar amp. Works really well with cleanish or modulated sounds. Turn on any kind of overdrive pedal and all hell breaks loose though there is enough distortion without to give me a reasonable 'show me the way' vibe

The hardest part is fitting the tube to the speaker. Plumbing store was my friend

[fallenturtle]

You want a phenolic diaphragm.  Your Newark link isn't working, but the others mention a Neodymium diaphragm, not sure if they mean the magnet or what.  Anyway, you don't want a metal diaphragm, especially with a cheap SS amp (hey I used a $5 First Act for mine!).  10 watts is plenty.  Your Kustom's "50W" probably refers to power drawn from the wall outlet.

Thank you for the headsup on the link, I've fixed it. Unfortunately Newark's site doesn't mention what the diaphragm is made of and I've had trouble finding a spec sheet on this driver. I was originally looking at a related driver that's apparently been used by others for talkboxes, and while it does have a spec sheet it doesn't actually say anything about the diaphragm: https://www.newark.com/mcm/54-060/compression-horn-driver-60w-rms/dp/39C1410 This one on order though which is why I was looking at the 54-050.

How big of a difference are we talking between the materials... is it a sound quality thing for chance of blowing the driver?

[Mark Hammer]

The hardest part is fitting the tube to the speaker. Plumbing store was my friend

Some folks use a funnel.  When PAiA adapted the Pygmy battery powered portable amp for talk-box purposes, they simply had a plastic bezel fabricated to retrofit over the speaker and fit a tube-end onto.

[willienillie]

is it a sound quality thing for chance of blowing the driver?

Sound quality.  The metal diaphragms can tend to be harshly bright.  I mentioned that I used a cheap First Act amp, I have to run pedals in front of it because it has no tone whatsoever, and it's still pretty "solid statey" sounding even through 7' of vinyl tubing.  I'm using a low-power 1960s Oxford driver that I had to hacksaw the horn off of (it was free), but it has a phenolic diaphragm, I can't imagine how bad it would sound with titanium or something.

While there is no standard driver for talk boxes per se, a commonly used one would be the JBL D250-X, not the cheapest option, but rated for 150W it should last a lifetime.  And the common threading means you can find "standard" adapters to connect the mouth tube.

https://www.parts-express.com/selenium-d250-x-gw-1-phenolic-horn-driver-1-3-8-18-tpi--264-204?gclid=EAIaIQobChMIvaKQ-tTm6AIVxkXVCh1G3QBcEAYYASABEgKW4PD_BwE

Someday I will get around to properly building a talk box, as opposed to the low-budget hacked-together experiment I have going now, and I intend to use that same JBL driver.