[sdiy] transducers

[harrybissell]

Remeber you want to TWIST the spring, not shake it end to end.  The official
method
is a tiny cylindrical shaped magnet, between the poles of a U shaped
electromagnet.
The tiny magnet is glued in place in such a way that when the electromagent is
energized,
the tiny magnet twists into a new position.

I thought it worked by shaking the spring (at one time) and was spanked onlist,
so learn from
my pain :^P

H^) harry

jhno wrote:

> >http://www.prosoundweb.com/recording/tapeop/plate/plate6.php
>
> i don't know about you all, but i would not fork out 90 clams for a
> "specially designed coneless speaker type" until i had tried a few
> specially modified coneless speakers.
>
> you can obtain a perfectly serviceable transducer by removing the cone from
> the speaker of your choice. in fact the only reason to remove the cone is
> to make the thing quieter; if it is for a plate in a closet this might not
> even matter. you can drive the transducer with whatever DIY amplification
> works. a speaker or piezoelectric element can be used for a pickup.
>
> mechanical coupling then becomes the crucial issue. i have coupled tension
> wires to dust caps before without inflicting any other damage to the
> speaker. a piece of stiff wire, popsicle stick, etc. glued to the cap or
> voice coil can form a bridge between the speaker and the wire/spring/plate
> under tension. you can experiment with this coupling (including the angle
> at which force is transmitted) to get a sound that suits you.
>
> admittedly this is a circuitous path if the goal is to sound just like an
> EMT plate. if you pay $35 for a "Passive Drive Signal Response Shaper,"
> (read, EQ) you are definitely paying for their time spent finding the right
> values, not the cost of the components.
>
> however, i would rather have an adjustable spring reverb any day. sometimes
> you need that twang. digital plate reverb algorithms sound quite good,
> whereas digital spring reverb algorithms are, to my knowledge, non-existent.
>
> for any mechanical reverberation device, an adjustable bandpass filter on
> the input can unlock a surprising range of sounds. on a spring reverb, you
> can use it to hit a specific frequency for maximum poing, or attenuate that
> frequency to smooth it out. this is much more useful than EQ'ing the output.
>
> jhno