I've been thinking about building a plate reverb unit and I have been researching them and they seem like they might not be too dificult to make. I found a good article in Tape Op that goes pretty step by step though the process

http://www.prosoundweb.com/recording...late/plate.php

My only real issue is that I'm not sure where to get the coneless speaker device to use as a driver. Any ideas?

Hi
Either a google search or Pro audio DIY?
How about a speaker with a rod glued to the coil cap (metalic cap type).
A solenoid with a pole piece that is reduced in size to stop it from rubbing may give some effect but probably limited in the HF response.
Have fun
Matt S

don't they typically use something like a piezo speaker? if so you can buy one for relatively cheap

Hi
A pizo speaker would probably not be able to kick the plate hard enough to get any decent signal out. Pizo pickups maybe.
Matt S

The solenoid would need a magnet in place of the plunger, else the motion would be pulling (or pushing) on both halves of the driving signal.
Having considered the DIY plate reverb questions myself, the "rod glued to diaphragm" approach sounds like a good one. I had considered a PA horn driver as the actuator, using a rod epoxied to the diaphragm on one end, and epoxied to the plate on the other. For a pickup, a stereo piezo phono cartridge would probably work nicely, both channels wired antiphase to pick up the vertical mvement at the stylus. These are cheep enough you could probably use several at various places about the plate.
One thing about these DIY projects, just like traveling, there are many ways to get there, and roads girdle the globe. Hope this route helps to get you somewhere.

Hi
Sorry, I should have said that the new 'pole piece' for the solenoid would need to be a magnet, howeverI expect that other drive methods would be better anyway, some form of loudspeaker with bar attached probably being favourite (and cheap!)
Matt S

No apology needed bro. If I let all these "ah gee, I didn't consider that"'s, stop me, I'd oiling squeaking swing sets for a living, or something like that.

On the subject of a driver, you're probably really close on using a loudspeaker. My brain seems to vegetate on using a PA horn driver. A lot of these have a phenolic diaphragm. Modifying this to act as an actuator would probably work like this...

You will need,
a working PA horn driver,
a Nylon threaded standoff, length to reach from the PA driver's diaphragm to the plate,
Nylon screws to match said standoff,
a couple of fiber washers,
"Glyptal", threadlock, superglu, ah heck 'borrow' some fingernail polish from your wife/girlfriend/sister/self,
A couple of cotton balls
patience and steady hands.

1) Disassemble front of driver exposing diaphragm, and remove any phasing plug, screen, hornets nest or other obstruction from the snout of the driver.
2) CAREfully remove the diaphragm, and REALLY carefully drill a small hole in its crown to accommodate...
3) a Nylon screw and fiber washer which will be inserted from the magnet side of the diaphragm. With the screw sticking out the front of the diaphragm, add another washer, then the standoff. Working from the magnet side of the diaphragm, the stack would go as follows.
Nylon screw,
fiber washer,
diaphragm,
fiber washer,
standoff.
4) Using your locking material of choice, paint over the hardware at the rod/diaphragm interface. No need to cake the stuff on, a little goes a long way. If there is material on the pole piece under the crown of the diaphragm, remove that which will interfere with the new hardware. Allow the locking material to dry.
5) Reassemble the diaphragm onto the magnet assembly.
6) Reassemble the front of the driver, taking care not to collide with the new appendage.
7) Roughly mold a cotton ball or 2 to fill the space between the actuator rod and inside of the driver snout. This is to keep the rod in place and not deform the diaphragm.

Attaching the actuator to the plate will require a bracket to take the threads of the driver so the distance from the diaphragm to the plate can be "fined in" by screwing or unscrewing the driver.

The driver's drive requirements are likely to be very modest, since driving the plate it will be doing so mechanically and thus "loafing" for the rest of it's life.

Whaddya think?

Hello to my "neighbor", Kansas Audio Works....

From the DIY forum that I moderate for TapeOp, here is a recent thread regarding DIY plate reverbs:

Tape Op Message Board :: View topic - Another Plate Reverb

The driver the folks have been looking at is a Vidsonix "Ghost", which was originally designed to turn a wall/whatever into a sound radiator:

Vidsonix Tactile Transducer

In that DIY thread, some people found the Ghost for around $25 on ebay.

Bri

Hi
Either the speaker, horn driver or the unit mentioned by Brian would work and as the whole thing is an experimentation project you could use any, possibly 2 different driver types which could produce different effects.
The main part is hanging the plate itself then 'playing' with different transducers.
I could not open the last horn driver I looked at because it had spent about 30 years in a church tower and had corroded solid otherwise I may have suggested it.
Have fun and keep us posted if you get it going.
Matt S

I happened to see the Vidsonix drivers within hours of the post, and it seems like a good way to get there as well. Thinking in terms of actions and opposite reactions, I can only imagine that the inertia of the driver is what anchors it against the plate. I'm curious now if the anchoring of the driver to the frame really makes that much of a difference. There's that "ah gee, I didn't consider that" all over again. Then again, my idea using a modified PA driver requires a sturdy anchor in the first place.
In my mind, I always considered the frame of the plate reverb as part of the actual mechanism itself. That's why it always made sense to me to tie the housings of the moving parts (transducers) to the frame itself, even if it meant damping the frame from the rest of the world.

Hmmmmm...thinking back to an actual EMT plate, the magnet section was attached to the framework, with only the voice coil attached to the plate.

The Vidsonix device goes in another direction for this application.

Bri

PS to Kansas Audio Works....looks like a road trip back to Salina again in a few weeks. Maybe I should make a pit stop half-way there, just to "meet and greet"! <g>

My service tech who is supplying an EMT-140 stereo plate reckons the plate sound is mainly due to the steel plate itself! he waffles on about the type of metal that is used and how the steel was mined from a certain place in Wales he reckons this is the only place in the world for good sounding metal! and at the time EMT seemed to be aware of this. I would say it's better to try & get an old EMT 140 and refurbish it. The drivers and pickups were quite special also, and especially the earlier ones that had a warmer filter curve!
He also mentions the valve versions were noisy had 30 db signal noise ratio and there is no way of getting rid of the hum, the later transistor versions had 60db signal to noise figures and are a lot more reliable.

In my oppinion any plate would soung better than digital versions if built well and with good components... Home and studio recording magazine in the uk ran about 4 pages on the subject (how to make a diy plate reverb)in the early 1980s i will one day photocopy the pages and put them up on the net!

Note: the EMT-140 plate sounds way beyond good and more towards knock out!

Made one myself. Used a 2x6 wooden frame. Works pretty good.




DIY Plate Reverb Unit nearly finished. - Home Recording

More info in the link. Sound samples near end of the thread.

I found/scanned this article from a 1983 issue of Modern Recording magazine.

http://www.brianroth.com/library/buontempo.pdf

Best,

Bri

cool beans!

Hi dfpratt,
I have not yet read the article you linked but I have read another one in the past. I don't know if I am remembering what I read or if I just thought this up, but what you'd want is a driver without the cone, so, remove the cone. Really it's that simple, you cut around the voice coil and dustcap, (okay maybe 1/4 inch up from the spider, or else you'll cut it) and then you cut away the cone from the edge of the speaker basket.

You'll be left with a half-canibalized speaker that has less "suspension" because half the retaining material (the cone) is gone, so it's gonna be a bit more loose - until - you attach it to the plate.

You can even cut the basket so that the voice coil "cylinder" can be mounted flush to the metal plate.

ANyway, whatever you do, have fun. And we want soundclips!

2N

Whoever mentioned the thing about special steel being used in the original EMTs is right. Not to dissuade anybody from building their own plate but I've built two in my time and could never get the cold rolled metal to sound right. Then I got my real EMT. Even before I ever plugged it in I took a quarter to it and brush it passed the steel and voila, magic. None of the sheets of metal I used in my homebrews ever shimmered like that. I never tried stainless steel in my home built plates, but Jim Cunninham the plate guru once told me that he used stainless in all of his ecoplates because it was way more consistent sounding.

This talk of shimmer makes me wonder if a large cymbal be used (e.g. 20" ride)?

This is still far too small IMHO

20'' dose not have to be to small, other variable would determine that, but i do think a 20'' cymbal would be to small and to heavy.
it would most likely work but not be that great. just to but mass for the size.

Hi Mr Bova, what did you use as the "emitter" transducer? A system similar to the EMT (like I described)?

I built a plate and had a metal frame welded up and used stainless steel for the plate itself. It was approximately 4'x6'.
It was a fun project but it really never had any magic to the sound. I only used it for a "retro" sound on steel guitar, it was pretty good for that. Getting any top end shimmer seemed an impossibility. The tensioning was always a problem for me and I stripped out many attempts to pull the tension up to where I wanted it.
The plate now sits unused in a back room and every once in a while I think of taking another whack at it......doubt I ever will.

hi folks,

I'm in the process of making a plate reverb, but I've got a question for the people who've had experience with making one! What would be the best option: using a linear speaker or using something like the Vidsonix "Ghost" speaker?

Opinions and advice regarding diy plate reverb in general will also be appreciated

Thanx

See info at my post #16. All you need is a regular full range speaker capable of handling 20 watts or so.

I used the Vidsonic driver (basically a speaker without a cone). Just screwed it directly to the plate.

I've experimented with various cymbals using a phono cartridge as the pickup - needle resting against the cymbal. I'm just tapping the cymbal for now to see how it sounds.

Basically the decay is way too long, even with an 8" splash. Also the sound is very "gong"y or like a deep bell, at least that is the sound picked up by the needle.

It would be super amazingly cool if someone who has a real EMT plate could record the raw sound of the plate itself (using a mic, not the built in pickups).

I'll try to do this next time I'm giving my EMT a tuning.

I just came across Jim Cunningham's site (creator of the Ecoplate):
JCC & Associates - Home of the Ecoplate and plate reverb parts

Some great resources here. Firstly he sells pickups, drivers and other parts. Secondly he has very detailed construction plans for a plate reverb:
http://platereverb.com/manuals/Plate%20Construction.pdf

Interestingly he says stainless steel plate will work fine.

THE ONLY PROBLEM IS IF YOUR STUDIO IS IN YOUR LIVING ROOM, EVERY TIME YOU WALK BY BY OR SPEAK IT VIBRATES LIKE CRAZY. I BUILT ONE AND IT ANNOYED ME SO MUCH I PUT IT IN STORAGE (UNTIL I HAVE A STUDIO THAT'S NOT IN MY LIVING ROOM LOL)

This is the one I built.
I make plans available for anybody interested (acad).

Vidsonix Ghost is a very easy and effective way to go.

Email me if interested in the drawings.



A sound sample (the reverb comes in and out...)

http://www.sknote.it/download/reverb...est_020709.wav