Reverb and resonance

Keith Hilton · From: 248 Laurel Road Ozark, Missouri 65721

I've been reading about reverb springs,drive
coils, and sensing coils for the reverb springs. Something keeps popping up in my mind. Wonder what else would work besides springs? I'm not talking about creating reverb with electronic chips or DSP. I just know there has to be other ways of creating reverb, or resonance, using some other electro mechanical means besides springs. In other words, what could be driven with a driver, creating resonance, then sensed? Have any of you ever experimented with anything besides springs?

Everett Cox · From: Marengo, OH, USA (deceased)

Well, Keith, of course there are other ways to have a primary sound source interact with some device to produce a secondary, 'resonate' sound. The trick is to create a delay between the two sounds. The way an induced vibration travels along the length of a spring makes for a mechanical device that's hard to beat.

Many of us have used tape delay devices.

Years ago, I experimented with air-coupled setups. In simple form, expressing the primary sound at one point within an enclosed air space and 'picking up' the resonate wave at some different point. Something as primitive as a 4ft section of 6in plastic pipe with a mic at one end will work when the other end is placed in front of the amp speaker. Feedback is a major problem but can be alleviated by careful orientation of the plastic tube. Feedback would be eliminated by having the mic drive a second amplifier.

The size and shape of the enclosed air space, along with the relative sound points, resulted in a wide variation in tonal/timbre qualities. Another reason I tried such an inelegant device was to 'enhance' the rather under-powered amps which my budget forced me to use.

The air-coupled device could be 'tuned' to emphasize the low register and make a 15 watt amp sound more like a 50watt. Not a lot louder but a deeper sound. Like when we used to put resonaters on the end of our car's tailpipe to get a more powerful sounding 'growl'.

None of my experiments produced a sound that was closely similar to the original but there were some different, and pleasing, results. Anyway, it was fun. --Everett

[This message was edited by Everett Cox on 18 May 2001 at 01:31 AM.]

mtulbert · From: Plano, Texas 75023

Hi Keith,

My age is showing with this post but before the DSP days in the studio we used a device called an EMT.

This was a huge thin steel plate that was literally suspended by wire clips in a wooden box. The plate was then excited with the signal and the result was pretty good sounding reverb. Not practical to take on the road. Maybe with today's modern electronics a portable version could be made.

Just a thought.

Mark T.

Jack Stoner · From: Kansas City, MO

Reverb is a combination of a slight delay (most spring units are in the 30 ms range) and something to repeat the delay with a decaying affect.

The spring seems to be the ideal mechanical method of doing this. In combination with more than one spring (each with a slightly different delay) it povides the delays and then with the mechanical movement of the sound through the spring it provides the additional (lower volume level) decay. There is not a wide frequency spectrum needed for the reverb effect so a "high fidelity" device is not needed. There are other methods, such as plates, ambient room or halls, etc.

Electronically the reverb can be simulated very well and there are units that do a very good job of reverb. For the purists nothing can replace the mechanical reverb, but for most situations there are electronic units that work very satisfactory.

Plate reverbs have been used in studios for many years, they are relatively high priced and not as portable as the lowly spring unit.

Then you could go the route of the elevator shaft, that was used as the first "echo" device by a Nashville recording studio.

Blake Hawkins · From: Florida

In the 1950's "Popular Science" had a construction article on a reverb which consisted of a 50 foot garden hose, microphone,funnel and a small speaker.
The funnel adapted the speaker to the hose.
The hose was coiled up and mounted in an enclosure which looked like an end table,
and the microphone was put on the other end.
It did work.
Also I saw an article somewhere where someone used a bowl of jello as a delay. I never tried that, though.
I, too, have worked with and serviced plate delays in professional recording studios.
One of the models had a pressure device which adjusted the period of the delay by pressing on the plate.
Blake

Bill Terry · From: Bastrop, TX

mtulbert... I remember seeing plans on how to build one of those plate reverbs using guitar transducers and some transformers. I believe the key was getting the plate under tension in the frame using some sort of turnbuckle type adjustments. Pretty cumbersome given how cheap and flexible digital devices are today, but it's still a viable sound I guess, it seems most digital reverbs have "plate" presets.

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Matt Farrow · From: Raleigh, NC, USA

The "bowl of Jell-O" may not be that far-fetched... There are older reverb units (not so many here, but more in the UK I think) that used a water tank and a set of piezo transducers for reverb. Problem is that water molecules aren't that elastic at low fequencies, so you have to modulate an 80kHz carrier with whatever you want to reverberate. A bowl of Jell-O may be more elastic at low frequencies due to its crystalline structure. Problem is that Jell-O is REALLY low impedance and you'd have to get around that with some high-excursion drivers, I bet. Worth a shot, anyway! At least a Jell-O shot

!

Don't forget the infamous and highly toxic Tel-Ray / Morley electrostatic delay line - it used a tuna can full of PCB transformer oil and a rotating aluminum disc.

Fender / Arbiter Soundette - used a rotating magnetic disc, like a primitive floppy drive

Binson / Guild Echorec - didn't this use a magnetic wire instead of tape?

I also saw a great idea on the web somewhere - let me look for it...
http://www.minimal.com/rvrbtr/ - this guy built a Strat with double-long whammy bar springs, then put a pickup on them.

Hmm - there's also the "echo chamber," which is a room with fairly refelctive surfaces in it, and you put a mic and a speaker in it at opposite ends...

I recorded a band once in this old house, and we had the vocal booth set up in the bathroom. By opening or closing the shower door you could adjust the amount of reverb on the voice, plus we had a PZM mic on the floor of the shower for just the reverb.

Don't forget the easiest way for steelers to get "reverb" or "resonance," which is the neck you're not playing! If you have a guitar that lets you have both necks on at the same time, you can get sympathetic overtones from your C6 neck while you play E9! (and vice-versa...)

There's a million cool ways to do it. Bart Hopkin has a book called "Musical Instrument Design," that's loaded with great ideas like that.

Matt Farrow

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Matt Farrow
Marlen 9-string 6+2
Kustom K150

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C Dixon · From: Duluth, GA USA

My eloquent friend Jack Stoner said,

"For the purists nothing can replace the mechanical reverb"

I believe that statement epitomized the ole saying,

"Build a better mouse trap and........."

Carl

Keith Hilton · From: 248 Laurel Road Ozark, Missouri 65721

Jello,50 feet of hose, now you really have me thinking. I found the Reverbitar site really interesting, and it even had electronic diagrams. Looked to me like the springs were strung over a pickup. That is really interesting! I will just have to do some experimenting along those lines. Mercury is somewhat like Jello.

Jack Stoner · From: Kansas City, MO

To add to the home brew,

My first reverb was made from plans in Popular Electronics or a similar magazine.

It consisted of a screendoor spring, a small speaker with parts of the cone cut out so it wouldn't make any noise and a phonograph pickup cartridge. The screendoor spring was connected between the voice coil on the speaker (input transducer) and the phono cartridge (output transducer).

All I can say about it is that it did work - not very well, but it did work.

C Dixon · From: Duluth, GA USA

Keith,

Please forgive me for digressing a bit, but here is a little history that may be of some interest; regard "reverb".

Working in the electronic's industry back in the 40's through the 90's, I saw many things come into being. And it has indeed been an incredible revelation and time in the history of man.

What with the advent of the triode vacuum tube by Dr Lee DeForest to the entry of the transistor by Bellabs, to the intergrated chip by RCA, it has been an awesome experience to have been a very small part of this technological explosion in my life time.

The reverberation unit as developed by the Hammond Organ Co. is one such item that even today has NO equal in my opinion. There may never be a unit that can top it as far as "purists" are concerned.

When I saw the first use of it outside the Organ was when Fender used it after a very successful entry into an already saturated musical industry market. I could NOT get over how much it added to the sound most of us were trying to achieve.

NO other unit until recent times so dynamically changed the sound of an amplifier. And came close to emulating the ambiance (reverberation) of sound waves in an auditorium.

And while there was a myriad of devices invented, the Hammond Organ spring unit had no equal.

The only other device I know of that was as dramatic an entry into the musical reproduction field, was the Bose speakers as designed by Dr Omar Bose and his students at a Massachusetts University.

His quest paralleled that of the Hammond Co in trying to capture what we hear naturally in a large concert hall when musical instruments are played.

Neither device does it 100% perfectly. And there may NEVER be a device that does, but they deserve a lot of credit for coming close I believe.

Unfortunately, the Bose concept never took off like many of us thought it would.

God bless their tremendous efforts and all of you,

carl

Sage · From: Boulder, Colorado

deleted

[This message was edited by Sage on 19 May 2001 at 08:25 PM.]

Gene Jones · From: Oklahoma City, OK USA, (deceased)

MTULBERT.....Let me show my age too..... About 40 years ago I played steel on a recording session once where we moved everything out of the "sound proof" studio into a long, tile floored hallway, so that we could get the desired amount of echo (reverb). As I recall, that studio was on the second floor of the Civic Center Music Hall in Oklahoma City. www.genejones.com

Donny Hinson · From: Glen Burnie, Md. U.S.A.

Keith...ever look inside a Fender Rhodes?

Dan Tyack · From: Olympia, WA USA

Dwayne Eddy used an unused gas tank for reverb (I am talking about an underground storage tank maybe 100' by 20' in which the engineers placed a speaker and a mike).

I personally much prefer the digital reverbs. It's all a matter of choice, clearly. I have heard some vintage reverbs which had interesting sounds, but most modern spring reverbs suck (IMHO).

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www.tyacktunes.com

Johan Jansen · From: Europe

Nothing can beat the special sound you get from a reverbing twin on a hollow stage where a heavy-weighted chick-singer is jumping up and down

But I agree with Dan! JJ

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c c johnson · From: killeen,tx usa * R.I.P.

Speaking of showing age,remember the "echoplex"? It used a circulating tape and had controls that would just about eliminate the echo and the reverb left was fantastic. I still have mine and I pull it out ever so often and whata difference. A soft warm echo and /or reverb. If I wasn't so lazy I would still take it out on jobs.

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Jack Stoner · From: Kansas City, MO

Funny you should mention the Echoplex.

Harmony Central has a current article on a solid state Echoplex that Gibson just announced. http://www.harmony-central.com/Newp/2001/Echoplex-Digital-Pro.html

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