Can Spring Reverb tanks be fitted inside small enclosures?

[kimelopidaer]

Basically, I wonder if the reverb tank surrounding the springs must be of a certain size for proper reverb to occur. I understand that the size of a room affects reverberation in real life situations; what if the spring were folded into an "S" shape and placed inside a container just the right size to contain it?


alright thanks!
K

[John Lyons]

Will a guitar string work if folded into an "S"?   
Same concept, it won't work. You need a certain amount
of tension to suspend the spring(s) in a straight line.

[Taylor]

John's pretty much right, but there are actually some folded spring reverbs:

http://www.sdiy.org/rfeng/Pics/rev1.jpg

They have to be tensioned by other smaller springs though, which will effect the way an impulse can bounce through the spring and change the sound to some degree.

[Galego]

Will a guitar string work if folded into an "S"?   
Same concept, it won't work. You need a certain amount
of tension to suspend the spring(s) in a straight line.

Well, if you get an object with great mass, like a star, maybe you could bend space, so it could work...

[Mark Hammer]

Essentially, as a mechanical device, the length of the springs determines the quality of the delayed signal, and to some extent the amount of electrical energy required to drive them.  What you want is for the springs to continue jiggling for a bit after an impulse is transmitted.  If the springs are too tight, that vibration will be damped near instantaneously.  If it's too loose/compliant the energy won't be transmitted efficiently.

Next time you take a bath, do this experiment. Wait for the water to settle down and make a wave at one end.  The wave will go to the other end of the tub, bounce off the end and go back where it started from.  If there is any energy left, it will bounce again and reverse directions.  Meanwhile, the wave will not go in just one direction, but bounce off the sides as well.  This is very similar to what a spring does, and how it creates something qualitatively different than a simple analog echo device.

The longer the springs the longer it takes for the signal to bounce back, emulating a slightly larger reverberant space.  It will also take longer for the spring to dampen so you get a richer sounding, longer-lasting reverb.  And if there are lots of springs (e.g., 3 lengths instead of 2) the reverb sounds even better and more complex.

One way that manufacturers have attempted to achieve greater length in a smaller package is to use a Y-shaped configuration, where one spring is joined to two others in the middle.  Depending on the angle it adopts at the joint, some percentage of the total overall length is saved (hard to imagine it's more than 15%, but that's something).  The pan is, of course, a little wider, and the signal is driven at one point, and sensed at 2.

A half dozen years ago, I was experimenting with a little DIY spring assembly, using some springs I bought at the hardware that were of suitable compliance.  One end was epoxied to the dome of a small loudspeaker driven by a 386 headphone amp chip, and the other end was soldered to the middle of a piezo disc suspended in a cartridge.  I used one of Forrest Cook's reverb circuits, and it was reasonable decent-sounding.  Not fabulous, but acceptable.  It came in at around a 10" x 4" footprint, which is a good deal smaller than the typical Accutronics pan.

[Taylor]

Will a guitar string work if folded into an "S"?   

Not quite an S, but this might interest you:

http://www.acoustics.org/press/151st/Leger.html

[EATyourGuitar]

http://www.freestompboxes.org/viewtopic.php?f=1&t=4593#p51695
the van amps stuff already does this. theres a gut shot on FSB

[John Lyons]

Ok, Ok stand partially corrected. 
I wasn't thinking of joined secdtions when you said "S" and folded.
But the single length, longer sustain is the best sounding for
natural reverb 1 2 or 3 springs. Longer...

[Top Top]

[Mark Hammer]

In theory, one could have a W kind of configuration.  The trick, of course, would be some means of suspending the structure in a way that didn't absorb too much energy, while allowing the spring sections to couple, physically, in a way that DID transmit energy with reasonable efficiency.  Normally, when you buy a "2-spring" reverb pan, there are actually 4 springs. Two springs in series have their end-loop soldered together in the middle.  This is done to balance off compliance and stiffness.  In the normal context, that physical coupling of two springs in series is suspended on its own, and not held up, except by the very ends.  In this hypothetical W configuration, the 3 points where the 4 springs are joined would need to be suspended from the sides of the pan.  It CAN be done in a manner that doesn't suck away too much energy, but it would be very tricky and require some serious thought into materials.  Whether it would sound any good after all that, I have no idea.

Incidentally, some 45+ years ago, you used to be able to get spring reverb units for car radios to make them sound "bigger": http://www.swtpc.com/mholley/PopularElectronics/Feb1966/PE_Feb1966.htm

[petemoore]

  I have a <6'' tank here, not really a tank but spring/transducers assemblage.
   Mass [can be messed with] on a spring [can also be massed with].
  Spring stock thickness before it's made into a coil...is a factor in how much mass the spring has, as does spring stock length....coiling it obviously increases length..and mass.
   I've seen slinky's, plates and various other types of spring - hardware used as reverberator-resonators.
   
     

[boogietone]

Just get you some of these: http://tinyurl.com/NanoSprings. Better than SMD and sure to fit in any Hammond box you want. 

[Greenmachine]

Nanosprings ...

you'd need tweezers for the tweezers.

[Mark Hammer]

The goal, of course, is not to get the smallest springs, but to get the longest effective spring length possible in the smallest footprint.