Quick question for anyone - why is it that the diffraction inside a compression driver is generally perceived as inaudible?
Maybe two potential candidates for DIY compression drivers: OT19NC00-04 and OX20SC00-04. Tweeters without faceplate could be equipped with a matching phase plug and/or horn.
Because they're trapped in the box by the throat's high impedance and can't reflect back through the diaphragm since it's sealed off in back.
GM
FWIW, Altec horn loaded microphones for [super] tweeters til increasing SPL/power demands doomed them to history.
GM
GM
best fullrange driver for talkbox
I don't know if it is the right place to post this cuz I'm new here, wellcome all enthusiastic and collaborative members of this comunity...
I wanted to know if it's better to search for an appropiate fullrange driver for my talkbox project (AKA vocoder) (I'm currently using a dismantled siren driver to attach the hose) , or find here the best design to print my own personalized optimus performance - weight - size - price - diaphragm and or driver which seems to be the fun and best option which came into my mind when I saw such a lot of info and such talented knowledge members here. So I thank a lot in advance any advice ideas etc. you can throw this way, you can reach me at my mail pauloandes in gmail, facebook/concienciauniversal, whatsapp +573006230050. Again thanks a million for yor time and collab.
PD: Uploaded an image I found on internet which is the way it is supossed to be connected if the driver is one of those PA horns which has a high range and need the bass or low sounds to be attenuated by a circuit.
I don't know if it is the right place to post this cuz I'm new here, wellcome all enthusiastic and collaborative members of this comunity...
I wanted to know if it's better to search for an appropiate fullrange driver for my talkbox project (AKA vocoder) (I'm currently using a dismantled siren driver to attach the hose) , or find here the best design to print my own personalized optimus performance - weight - size - price - diaphragm and or driver which seems to be the fun and best option which came into my mind when I saw such a lot of info and such talented knowledge members here. So I thank a lot in advance any advice ideas etc. you can throw this way, you can reach me at my mail pauloandes in gmail, facebook/concienciauniversal, whatsapp +573006230050. Again thanks a million for yor time and collab.
PD: Uploaded an image I found on internet which is the way it is supossed to be connected if the driver is one of those PA horns which has a high range and need the bass or low sounds to be attenuated by a circuit.
Attachments
1) The Instruments and Amps Forum (Everything that makes music, Especially including instrument amps) would be a more appropriate place to post your question, but since your here:
2) A phenolic diaphragm thread on PA or siren driver is still the best choice for a "talk box". Depending on the source material, volume desired, and low frequency capability of the driver, a highpass filter and attenuation may be required. That said, a 10 watt amp can rattle your fillings out without causing any harm to a 30 watt siren driver directly connected.
Attempting to create a better driver for the purpose would cost far more than what commercially has already proven to work great since 1969.
Talk boxes put the loudspeaker's output into a person's mouth through a tube, where it is modulated by the entire vocal tract, then picked up by a microphone for recording or live sound. A vocorder is a completely different device, using a synthesizer that produces sounds from an analysis of speech input, processing both the carrier and the modulator signal integrally, producing the output as a separate electric signal.
Art
I used Selenium D250-X and a cheap 10W guitar combo with distortion for my talkbox experiments. It was a cool effect, but a bit unpleasant to use, so it collects dust in the garage. Maybe I had too much low end in the signal, but it was really rattling my teeth.
change driver or amp?
I am so glad... amazed, to see such a fast response. Thanks a lot for your advaice about the correct place for my post,and the correction about talkbox and vocoder, next time I'll google it a lil more, and thanks a lot for also give advice about the driver I am using, so I will throw a last cuestion: I was using an old FirstAct M2A-04 which uses a 110v/14V AC/dc with this specs:
Power (Watts/Ohms): 4 / 4
Speaker Configuration: (1) 6.5"
And the driver is a 20w siren, which I took the alarm sounds board module apart.
I am bypassing the amps Loudspeaker by disconecting its red wire and conecting a "crocodile" (that's the local name for that metal gripping piece attached or soldered to a cable) to the center pole of a 3 pole switch (see image), and one of the outer poles to reach one of the driver's poles. And keeping the black wire of de loudspeaker in its place, i put another croc grip to reach the other pole of de siren's driver.
Do you suggest I use a 15Watt amp or a lower wattage siren driver??
I am so glad... amazed, to see such a fast response. Thanks a lot for your advaice about the correct place for my post,and the correction about talkbox and vocoder, next time I'll google it a lil more, and thanks a lot for also give advice about the driver I am using, so I will throw a last cuestion: I was using an old FirstAct M2A-04 which uses a 110v/14V AC/dc with this specs:
Power (Watts/Ohms): 4 / 4
Speaker Configuration: (1) 6.5"
And the driver is a 20w siren, which I took the alarm sounds board module apart.
I am bypassing the amps Loudspeaker by disconecting its red wire and conecting a "crocodile" (that's the local name for that metal gripping piece attached or soldered to a cable) to the center pole of a 3 pole switch (see image), and one of the outer poles to reach one of the driver's poles. And keeping the black wire of de loudspeaker in its place, i put another croc grip to reach the other pole of de siren's driver.
Do you suggest I use a 15Watt amp or a lower wattage siren driver??
Neither.
You are connecting your siren driver to what amounts to a plane wave tube, one end of which will be inserted somewhere in your mouth or throat.
Even at the low E note of a guitar (81Hz) most screw on siren drivers are capable of over 120dB into a plane wave tube with just 1 watt, mid band (1kHz-4kHz) it may exceed 140 dB in your mouth, which may be well above your pain threshold, and can cause hearing damage in short order if you stick the tube near your ear.
Your FirstAct M2A-04 may do around 90dB SPL (sound pressure level) at one meter.
A 10 dB increase in level sounds twice as loud. Each doubling of distance imparts a 6dB loss in level, but not in a tube- what goes in comes out nearly the same level.
You don't mention the siren driver impedance, it could be from 2-16 ohms.
Your 4 watt/4 ohm amp probably delivers 2 watts into 8 ohms, or 1 watt into 16 ohms, still likely more than enough to be as loud as you would ever sing.
I attenuate the output of my Valve Junior practice amp to under a watt when using my current (70 year old) Jensen Hypex talk box driver.
Tape your tube to the driver, clip lead the driver to amp output, play around like Peter Frampton, Joe Walsh, or Roger Troutman, funky keyboard players groove on talk boxes too.
Art
Not to forget Johnny Guitar, who perhaps chose to smile with a brace (sorry:set) of gold front teeth for a reason… A Real Gold Tooth For Ya
How about using a hard surface drive a comp’s phase plug instead of adjusting
- a phase plug to make up for soft diaphragm modes
- tricking around with adding mass to soft dome centres in order to compensate for wave travel time from coil contact to other areas of membrane?
Both of the above are prone to loose „tuning“ once the soft diaphraghm changes strength due to ageing in stressed or even all parts of surface.
Ralph
- a phase plug to make up for soft diaphragm modes
- tricking around with adding mass to soft dome centres in order to compensate for wave travel time from coil contact to other areas of membrane?
Both of the above are prone to loose „tuning“ once the soft diaphraghm changes strength due to ageing in stressed or even all parts of surface.
Ralph
Patrick (John?) do you remember how destructive a process it was to remove the phase plugs and throat from the B&C DE5's? Is it just a matter of removing screws or do pieces need to be cut or adhesive removed? Also, are the phase plugs part of the magnetic circuit of these compression drivers or are they just an acoustic extension here? If just acoustic, I'm hoping that resin 3d printed replacements might be a possibility. I see from some of your posts after this thread you've soured on the idea of designing your own phase plugs but I've got some ideas.....
Dan
I have a set of DE7s and the phase plug is made from FG loaded nylon, at least that's what it appears to be. The other verification was that it wouldn't hold any cyano adhesive.
I actually took apart a celestion 1430 CD and found they use no dampening in the pole piece, so I added some melamine sponge discs, which cleaned up the primary resonance a little. This driver uses FF so I had to make sure it wouldn't wick and soak into the sponge material.
The DE7 sounds nice in a small WG made from 3 layers of BB stacked and routed with a conical 60 degree bit and rounded at the mouth. It plays to past 17k.
I actually took apart a celestion 1430 CD and found they use no dampening in the pole piece, so I added some melamine sponge discs, which cleaned up the primary resonance a little. This driver uses FF so I had to make sure it wouldn't wick and soak into the sponge material.
The DE7 sounds nice in a small WG made from 3 layers of BB stacked and routed with a conical 60 degree bit and rounded at the mouth. It plays to past 17k.
This is a BMS 4526HE, a ring radiator with a 16mm exit. It sells for $90, or nearly four times as much as the Vifa.
Here's the equalized response of the Vifa and the BMS, on the same waveguide. The BMS is getting approximately 20dB LESS power.
Here's the published curves of the two drivers. The BMS is about 15-20dB more efficient than the Vifa.
For $150, the BMS would be a great compression driver, but at $90, it's a steal. Due to the small throat and small size overall, it barely needs any EQ at all to play out to 24khz.
But despite it's great performance, the $25 Vifa still outperforms it, for hi-fi, IMHO. This is for two reasons:
1) The Vifa has significantly wider bandwidth. This is due to higher displacement and a dramatically larger back chamber. The back chamber on the BMS is almost non existent.
2) The Vifa is smoother.
But the BMS is really REALLY nice, nonetheless, especially at this price point.
Normally, I do my measurements at about 100dB. Out of morbid curiosity, I cranked up the SPL on the BMS to intolerable levels and dropped the crossover down to 1200Hz. I did this because I was curious if it might be possible to get the BMS to play down lower by leveraging it's ridiculous efficiency. IE, the BMS is rolling off at 2khz, but it might be able to squeeze some bandwidth out of it by taking advantage of the fact that it has efficiency to burn. I didn't measure the SPL on this sweep, but I'd guess it was around 110-115dB. Even at this ridiculous SPL, distortion is "just" 1.59% and it's mostly 2nd harmonic.
One thing that was puzzling about the BMS, is that even when equalized, it sounds MUCH different than the Vifa. Subjectively, the Vifa sounds a bit sweeter and duller. If I didn't see the measurements with my own two eyes, I would think that the Vifa rolls off sooner, but it doesn't. I wonder if I might be hearing HOMs from the BMS; it has a very hard 90 degree turn in it's phase plug. The JBL ring radiator phase plugs, from Voishvillo, have a much more gentle transition from ring to throat.
Here's the BMS 4526HE polars on the same waveguide as the Vifa.
Here's the frequency response and distortion of the BMS at a level comparable to where I measured the Vifa. The BMS just crushes the VIfa in the distortion department.
For $90, the BMS is killer, but I like the Vifa better because of:
1) better polars
2) smoother response
3) a fraction of the price
But if low distortion is important to you, and you don't need a low xover point, the 4526HE is REALLY nice.
Attached is the STL file for the 3D printed waveguide for the BMS 4526HE that's shown in the post on page two of this thread.
Check out this post for some info on how to buy the compression drivers: https://www.diyaudio.com/community/threads/a-collection-of-3d-printed-things.376613/#post-7977291
