Which spring reverb is the "sproingiest"?

[Mark Hammer]

I'm going to go out on a limb here, and suggest that the most "spring" will be obtained when the spring is long and there are fewer of them.  I base this on the assumption that:

• "sproing" requires sufficient compliance in the spring itself to have a dominating wavelength
• differential tension/compliance in multiple spring pans distributes the spring around such that no single resonance dominates

That said, one of the aspects of the traditional Fender Reverb that made it desirable was the Dwell function, that determined how hard the springs were driven.  It's that initial big transient, telling the springs to "WAKE THE F*** UP!!!", from a deep sleep (resting position), that yields maximum sproing.  And if they are long springs, even moreso.

[Digital Larry]

For sure, multiple springs and/or springs joined in the middle help spread out the resonances.  As far as long/short I still haven't decided and as much as I've put forth a bunch of mathematical treatises on the subject I don't normally go into them much other than to think - factor in the numerator, so end result increases if it does - whether linearly or square rootedly or otherwise I don't care.

Your comment about the drive level is well taken.  Some of the papers I've read start with an assumption that the torsional displacement is very small, which aids in a linear analysis of the system, but what if it isn't?  What if you drive a garage door spring with a washing machine motor?  That's my idea of a manly reverb.   

[ElectricDruid]

You might have a look at old home organs too. The sproingiest spring I've ever come across was in a Yamaha BR-30 (I think that was the model) organ from the 1970s. I modded it to include an effects send/return, since the organ had an internal amp and a choice of 1x12" speaker or a single horn rotary speaker. With a soft drive pedal plugged into the effects loop and the reverb turned up, you could make the nicest chugging reggae organ stab sound I've ever heard. A large part of that sound is the spring's reaction as a overdriven stab hits it and makes it resonate. It had a long reverb tank, but I don't think I took it off so I don't know how many springs it had.

Tom