Reeded Plate Reverb.

After testing to prototype plate reverbs, one small sized standard plate just to test that i could send and receive signal to and from the plate, and the second just to test if adding tabs or "reed" like structures to the back had an effect, im now going to create what i set out to build, a Reeded Plate Reverb.

In the making of this reeded plate reverb, i cut 24 strips of tin (the same material as the plate) to approximately 0.5 cm in width x 7.5 cm in length. I then flattened each strip with a small hammer and bent over a small tab on a single end of the reed. This is the surface which will be soldered to the plate.

A third plate of tin was cut to exactly the same dimensions as the other two test plates (6 inch x 6 inch) and was marked out in a grid.

Each of the 24 reeds were soldered an inch apart in rows and columns of 5 reeds.

After placing the contact microphone on the plate (slightly off centre) and the plate back in the original frame with the original springs. Testing could begin with the same samples.

Result... SUCCESS! The plate actually sounds like reverb, all be it short, but there is a reverb effect that is audible. The reeds seem to have over come the pestering 400hz resonant frequency too.

Interestingly this plate seems to respond to higher frequencies better than lower frequencies. In my testing im using a clap, snare and bass drum sample, and this plate responds best to the clap sample were as the other two plates (due to there resonance problem) responded best to the kick drum or snare drum.

This is all because of adding the reeds, my theory behind this is that the reeds, soldered to the plate, not only add increased surface area but also interrupt the paths of standing waves across the plate, also the reeds create tension at the point that they are soldered to the plate creating different frequency characteristics.

Furthermore as the reeds are hand cut, shaped and soldered, no two are exactly a like, because of these small deviations in each reed (in terms of length, width, and the surface soldered to the plate) each reed does have  an individual pitch, even though they seem relatively similar in dimensions. I believe that this has the effect of thickening up the texture of the effect as so many different frequencies are effected due to the differences in each reed.

The signal from this plate is of much greater clarity than the two prototype plates due to its fuller and richer frequency content, however due to the greater amount of metal fixed to the plate, unfortunately the noise issue has increased, but mixed correctly it is not a major issue, but still has given me another idea.

I believe this noise issue could be overcome by a slight change in use. Instead of using this plate as an auxiliary effect off of a mixing desk, why not place this plate directly on the instrument you wish to effect, like you would a microphone. Especially drums as the loud transient sounds would require less gain. This could be the main advantage of this plate being small. Could it be used in conjunction with different microphone techniques and positions to acquire different characteristics? Why not?

Therefore im going to test this slightly different implementation and record the signal from the plate with it placed in a microphone position on a snare drum. But as it responds well to higher freqencies, what would it sound like on a guitar cab amplifying acoustic guitar, or a bass cab? I will test these implementations too. I will also record a dry sound of the instrument to use as a comparison, and to mix with the effect.  

Also i intend to add another contact microphone to the plate so that it can be used as a stereo effect, as this may also decrease the noise issue as less gain may be required, but also it may give the effect more presence in a mix.