Along with EQ, reverb is probably the most commonly-used effect in audio. It would be nearly impossible to find a recording that doesn’t employ some type of reverb.
And probably because it’s so ubiquitous, reverb is also one of the most misunderstood and misused effects there is. It’s interesting to consider that, as with so many things in modern life, we’ve spent countless hours inventing technologies that enable us to recreate something that occurs naturally in the real world.
It Starts With The Room
In the earliest recordings, reverb was limited to what occurred naturally in the actual recording environment. The acoustical fingerprint of the space itself was an intrinsic part of the recording, usually captured by one – or at best, a handful – of microphones.
Rooms with the best sonic characteristics (typically symphony halls, theaters, etc.) were prized as the most desirable recording spaces, and this worked well for the music of the day, which was mainly in the orchestral and operatic genres.
As the Big Band era dawned in the late 1940s and early 1950s, radio began to play an increasingly major role in the way audiences would consume recorded music. The advent of audio tape recording, along with refinements in microphone technology, enabled engineers to begin to experiment with mic placement, bringing with it an expanded ability to experiment with room acoustics.
One of the first documented uses of natural (ambient) reverb to intentionally enhance a recording was by engineer Robert Fine, who introduced ambient mics on some of the early “Living Presence” recordings on Mercury Records.
The Room Next Door
The late Bill Putnam, Sr., founder of Universal Audio, was an early pioneer in employing artificial reverb in recording. As early as 1947, Putnam converted a bathroom in his studio to create one of the first purpose-built echo chambers, placing a speaker in one corner and a microphone in another, and mixing the sound with a live recording.
The unique sound of the echo chamber on Putnam’s first release on his Universal Records label, “Peg o’ My Heart” by The Harmonicats, was an instant hit, and the sound of echo chambers went on to dominate the recordings of the 1950s. Putnam would design echo chambers for his studios in Chicago and Los Angeles as well, beginning a trend of studios creating purpose-built natural reverb chambers.
Today, the few of those spaces that still exist (including the still-active chambers under the parking lot of the Capitol Records building in L.A.) are prized today for their natural sound.
The Virtual Room
As revolutionary a concept as Putnam’s echo chamber was, it still required the natural ambience of a real space to work its magic. It wasn’t until 1957 that the German company Elektro-Mess-Technik (EMT) unveiled the first plate reverb. The EMT 140 (and subsequent units, including their best known EMT 250) worked by attaching a small transducer to the center of a large, thin plate of sheet metal; vibrations from the speaker activated the surface of the plate, and were picked up by one or more small pickups attached to the plate’s other end.
The result was a dense, warm sound that emulated a room’s natural echo, yet could be dampened to vary the sound somewhat. And while the EMT plate reverbs were large and unwieldy, they still represented a smaller, cheaper, and more versatile alternative to building a dedicated echo chamber.
Another variation introduced during the 1950s, spring reverb substituted a set of springs for the metal plate. Though not nearly as dense and lush a sound, the springs required much less space, making them popular in applications where plate reverbs were impractical, including early guitar amps (Fender’s being the most well-known) and Hammond organs.
It was the advent of digital technology in the 1980s that changed the face of audio overall, including reverb. Digital reverbs made it possible to emulate the natural ambience of any space, as well as the sound of plate, spring and other electronic reverb sources. Soon, an abundance of digital reverb and multi-effects boxes began to appear in studio racks.
Some of the most popular units included Lexicon 224 and 480, and Yamaha Rev7 and SPX90. These units even made it possible to modify individual parameters to create effects that don’t occur in nature, including artificially altering early reflections (the first reflected sound), pre-delay (the time before the first reflected sound is heard), and even reverse and gated reverb (probably one of the most abused drum effects of the 1980s).