Plate reverb is a type of audio processor that offers sonic complexity. It involves a large metal plate that vibrates in a two-dimensional way. To do so, it goes down the length and across the width of a steel sheet. Then, the audio signal feeds the driver, which is directly connected to the plate. When this happens, the plate vibrates. Plate reverbs have a unique design, as well as a peculiar sonic coloration capable of altering the timbre of many instruments. Because of the distinctive resonance of plate reverbs, modern productions take advantage of these devices profusely.
Plate Reverb: the Physics
Elasticity and mass distribution cause the speed of propagation of the plate. Their thickness and suspended tension influence this, too. Plate reverbs can slow the speed propagation of the air’s sound. These reverbs are small in size and are capable of producing echo sounds. Moreover, they can apply damping when placing liquids or porous materials against the plate. Plus, a sound engineer can adjust reverb time for production flexibility.
If you transfer sound through metal, high frequencies usually travel faster than low ones. When using plate reverb, the listener is able to perceive the former before the latter. Hence, in some cases, plate reverb is a better choice than a natural space. In contrast, in other scenarios, natural space is a better option.
A Bit of History
A German company created the first plate reverb device, known as EMT 140, in 1957. The EMT 140 was large, heavy, and quite expensive. Many soundtracks recorded between 1960 and 1970 used this device. Despite the large dimensions of early plate reverbs, their sonic qualities were optimal. The EMT 140 produced a slightly metallic sound that blended with several instruments, especially the vocal ones. Plate reverbs produce a bright, dense and smooth sound.
