Simulated space – vintage reverberation
Historically, early engineers were forced to rely on actual physical spaces to provide ambience. However, the use of real spaces is not always practical, nor does it offer any control over the size of the room. For this reason, an artificial solution was – and is – often required.
Early artificial reverbs were electromechanical devices. In 1939, Laurens Hammond patented a spring-based design for inclusion in the Hammond Organ. This sort of reverb funnels the signal to one or more suspended springs in a small enclosure. The excited springs then act to create some semblance of space.
Spring reverb units were commonplace among gigging musicians, and can be found built into certain guitar combo amps and early synthesisers.
In 1957, Elektro-Mess-Technik (EMT) began developing its now-famous 140 Reverberation Unit, a 240Kg behemoth that worked by exciting a suspended metal plate using transducers. Initially a mono machine, it made use of an ingenious dampening system in order to provide users with control over the reverb time.
With units installed at RCA’s studio in Nashville, as well as EMI Abbey Road, EMT’s plate reverb would find its way onto many a classic platter.
Other companies would introduce plate reverbs, but due to their size and weight, they were relegated to pro recording studios.
Digital reverb units first appeared in the 1970s. EMT’s rack-mountable 144 was released in 1972, but its limitations hindered its success. The company then collaborated with stateside company Dynatron in order to produce the standalone 250, a bona-fide multi-effects unit that counted digital reverb amongst its multitude of offerings.
A few years later, Lexicon would release its 224, the beginning of what would become a long and storied association with digital reverb.
These units simulated ambience by sampling the incoming audio signal and replaying many copies back with variations in pitch, phase and timing. The more sophisticated (and DSP intensive) the algorithm, the more realistic the sound.
The first in a legendary line of digi reverberation units, Lexicon’s 224 still sounds good today