History of Reverb and Echo in Audio Production Recording Natural occurring reverb goes further back than man on earth. Since before man, creatures and nature made sounds that created natural reverb and echo. But now in today’s age with men and the modern technology that they have created there are all sorts of ways to create reverb and echo. From big metal sheets to plug-ins in a DAW on a computer, engineers have found ways to incorporate and benefit from reverb and echo on a recorded audio track. But before skipping into today’s ways of recording reverb and echo let’s shed some light on what reverb and echo truly is and where it came from. Reverberation or as most people refer to it as reverb, refers to the way sound waves reflects of the surfaces around the sound source before it reaches the listeners ear.
Reverb is basically a series of multiple fast echoes merged together so fast that the human ear cannot separate the sound into a delayed distinct duplicate sound. When hearing exact duplicates of the sound is when it becomes echo. In the early days of radio, they would send the radio signal through a line miles and miles away and bring it back. An easy way to hear reverb is to enter an empty room and clap. Immediately after the clap the person would hear the decaying sound of the clap; that is reverb. Recording reverb in the early days was as simple as just backing up a microphone from your sound source to reach the right amount of reverb you were looking for. There was also tape echo where sound was recorded on one head and reproduces it with a different head. The space between the two determined the delay. There were also a few units that had several heads to give delays simultaneously. Engineers would also add feedback to a delay to generate repeated echoes. Les Paul took the tape machine and reinvented it in 1948 by adding another recording head. Another way to successfully produce echo was to use oil cans filled with oil called oil can echo. Wallace Clement Sabine founded the field of architectural acoustics. Bill Putnam Sr. was the first to use artificial reverb by using his very own reverb chamber, his bathroom. A reverb chamber is a hollow arena used to create echoing sounds. Building a room with non-parallel surfaces and then applying shellac to all the surfaces so make them acoustically reflective creates an echo/reverb chamber. A speaker and microphones in the room would pick up the reflection of the speakers output this method was very popular in the 60’s. Soon enough a new technology of reverb came about, Spring reverb. Sam Phillips of Sun Records had used tape echo when recording Elvis in the early days. Spring reverb is a type of electromechanical reverb device. It creates a reverb effect by inducing sound vibrations at one end of a long wire (which is coiled into a spring to decrease the amount of area it takes up, that’s why it is called spring reverb). Another transducer at the extreme end picks up the vibrations. As the waves reflect back and forth from one end of the spring to the other, and back, a reverb effect is produced. Spring reverbs have a harsh, trebly sound (and vulnerable to exterior shock), but they are inexpensive to build and provided a new way for reverb. Eventually the technology became more advanced and a new form of reverb was created; plate reverb changed the reverb game in 1957 when German company EMT (Elektromesstecknik) released the first plate reverb, EMT 140 Reverberation Unit. This plate reverb system used an electromechanical transducer to create vibration in a large plate of sheet metal. A pickup would capture the vibrations and the bounced across the plate, which resulted in output as an audio signal. The first units had one pickup for mono output; later models introduced two pickups for stereo use. A damping pad, made from framed acoustic slates, can attune the reverb time. The closer the damping pad is to the plate, the shorter the reverb time. However, the pad never touches the plate. Some expensive units also featured a remote control for ease of access. Some electronic forms of delay were to use bucket brigade chips that would hold for certain amount of time and release to the next chip. Now in these modern days a very popular way to produce reverb is through plug-ins or “programs” on a DAW or an outboard digital unit, this is called digital reverb. Digital reverb uses various signal processing algorithms to create the reverb effect. It creates multiple feedback delay circuits to produce a large decaying series of echoes. Digital reverb units or programs have many controllable parameters that can change different aspects of the reverb. Another form of digital reverb is convolution reverb. Convolution reverb is a process for digitally simulating the reverberation of a physical or virtual space. Many people prefer natural occurring reverb in a room than any processed artificial reverb. That’s why several studios have reverberation rooms where the music is recorded in, not processed. Many engineers would use different microphones mixed with each other. Many artists like to incorporate echoes or “delay” to their music. Noticeable duplicates of the sound source can create a very wanted ear catching effect, but can also be dangerous if not used properly. On form of delay is Echoplex, which uses multiple echoes, which recur in approximate synchronization with a musical rhythm.
Adding short-range delay to a recorded sound produces Doubling echo. To create this sort of delay the delay must be from thirty to fifty milliseconds, as commonly used. Longer delay times would result in Slapback echo. Slapback echo uses a longer delay time (seventy-five to 250 milliseconds), with little or no feedback. The effect was commonly used on vocals in the 1950s rock-n-roll records. It is also sometimes used on instruments, mainly drums and percussion. Analog and digital delay machines also easily produced the effect. Flanging, chorus are delay-based sound effects. With flanging and chorus, the delay time is very short and typically modulated. Reverb has been integrated to be used with many musical instruments. There are reverb knobs on guitar amplifiers to give you a bigger sounding guitar or as if you are in a large hall. They also have digital delay and reverb pedals for guitar to create great sounding loops and ambience sound. Reverb creates a realness of the sound and almost makes it “3D” as if the sound was played right in front of you. There are all kinds of forms of reverberation and echoes used in music ever since recording music was introduced and still used today. Reverberation could be one of the best effects for music and in any other aspect of recorded sound.