Methods of creating/applying Reverb (including Famous examples)
“Echo” Chamber eg: Abbey Road - Studio 2 Echo Chamber
Developments in electronics in the early 20th
century—specifically the invention of the
amplifier and the microphone—led to the
creation of the first artificial echo chambers by
playing recordings through loudspeakers in
reverberating spaces and recording the
sound. American Producer Bill Putnam is
credited for the first artistic use of artificial
reverb in music, on the 1947 song "Peg o' My
Heart" by the Harmonicats. Putnam placed a
microphone and loudspeaker in the studio
bathroom to create a natural echo chamber,
adding an "eerie dimension".
Acoustically speaking, the classic
echo chamber creates echoes in the same way as they are created in churches or caves—they are all
simply large, enclosed, empty spaces with floors and walls made of hard materials (such as polished
stone or concrete) that reflect sound waves well. The basic purpose of such chambers is to add colour
and depth to the original sound, and to simulate the rich natural reverberation that is a feature of large
concert halls.
The development of artificial echo/reverberation chambers was important for sound recording
because of the limitations of early recording systems. Except in the case of live performances, most
commercial popular recordings were made in specially constructed studios. These rooms were both
heavily insulated to exclude external noises and internally somewhat anechoic—that is, they were
designed not to produce any internal echoes or sound reverberation.
Because virtually every sound in everyday life is a complex mixture of direct sound from the
source and its echoes and reverberations, audiences naturally found the totally 'dry' and reverberation-
free sound of early recordings unappealing. Consequently, record producers and engineers quickly
came up with an effective method of adding 'artificial' echo and reverberation that experts could control
with a remarkable degree of accuracy.
Producing echo and reverberation in this form of echo chamber is simple. A signal from the
studio mixing desk—such as a voice or instrument—is fed to a large high-fidelity loudspeaker located at
one end of the chamber. One or more microphones are placed along the length of the room and these
pick up both the sound from the speaker and its reflections off the walls of the chamber. The farther
away from the loudspeaker, the more echo and reverberation the microphone(s) picks up and the louder
the reverberation becomes in relation to the source. The signal from the microphone line is then fed back
to the mixing desk, where the echo/reverberation-enhanced sound can be blended with the original 'dry'
input.
An example of this physical effect can be heard on the 1978 David Bowie song "Heroes", from
the album of the same name. The song, produced by Tony Visconti, was recorded in the large concert
hall in the Hansa recording studio in Berlin and Visconti has since been much praised for the striking
sound he achieved on Bowie's vocals. Visconti placed three microphones at intervals along the length of
the hall, one very close to Bowie, one halfway down the hall and the third at the far end of the hall.
During the recording, Bowie sang each verse progressively louder than the last and as he increased
volume in each verse, Visconti opened up each of the three microphones in turn, from closest to farthest.
Thus, in the first verse, Bowie's voice sounds close, warm and present; by the end of the song, Visconti
has mixed in a large amount of signal from all three microphones, giving Bowie's voice a strikingly
reverberant sound.
Spring Reverb eg:ELEFUNKEN ECHOMIXER
Spring reverb is an early form of mechanical
synthetic reverb. Similar in principle to plate, spring
reverb uses a coiled up piece of metal stretched
between 2 points instead of a flat sheet. As the
spring only ‘acts’ in one direction Spring Verb can be
said to be 1 - dimensional. (1-D)
A spring system has a transducer at one end of a spring to convert audio as a voltage to movement and
a pickup to take movement and convert it back to voltage at the other. This is very similar to the
technology used in plate reverbs. Reverb time can be adjusted by changing the spring tension.
In 1939, Laurens Hammond applied for the first patent on mechanical spring reverb. His namesake, the
Hammond organ, used a built-in spring reverb unit when it started being manufactured in 1960. Spring
was, for a time, frequently used for recording. They’re perhaps most commonly built into guitar amplifiers
since they’re pretty small and inexpensive to make. We can thank Laurens Hammond and Leo Fender
for each of their innovations.
Plate Reverb eg: EMT 140
As the name suggests, plate reverb features a metal plate suspended in
a box that is vibrated by a transducer (in the same way a transducer
vibrates the cones in your studio monitors to produce sound). Those
vibrations are captured by pickups on the plate reverb unit.
Plate Reverb units have a damper pressing up against the plate that
can be adjusted to change the reverb time.
Similar to its spring counterpart, the
sound of a plate reverb isn’t what
you’d expect to hear from a large
room. The result can feel natural, or if
you turn it up, you can create an
artificial-sounding, unique tone.
As a Plate Verb ‘acts’ both horizontally and vertically on the plate and has 2 pickups, it can be stereo and
can be thought as a 2 dimensional (2-D)
Digital Algorithmic Reverb eg AMS RMX 16
'Algorithmic reverb' is usually being used to describe a class of reverbs that use delay lines, loops and
filters to simulate the general effects of a reverberant environment in an acoustically acceptable manner.
Traditionally these would be hardware units, in a rackmount (with or without a separate control interface)
but more recently will commonly take the form of a plug-in in a DAW.
Algorithmic reverbs are typically best used for unnatural Reverb types including Non-Linear Reverse
Reverb, however many producers like the ‘vibe’ or quality of these units/plugins to emulate natural
reverbs.
Examples of a simple and more complex algorithmic reverb schematics…
Digital Convolution Reverb eg Waves IR-L reverb
A convolution reverb takes a sample from a real-world space
(called an impulse response or IR) and uses this to digitally
simulate the reverberation of that space. Only a convolution
reverb can capture the ambience of a real space, or real
hardware, and recreate it on a computer, with a convolution
reverb, you can easily access the reverb of many spaces, and
still tweak them.
Convolution Reverb allows for extended tweaking options such
as EQ, damping, modulation, and more. You can modify an
original IR to something completely new, and then resave the
design as a new preset.
NB Plugin Only
Impulse Responses are generated by capturing a burst of white noise in a specific space or through a
specific piece of outboard. Thousands of IR’s are available for free download from the internet.
Gated Reverb
Live room method Effects processor method
The oldest, most "natural" technique can be When using a hardware reverb unit, echo
executed with minimal electronic processing. chamber or digital emulation of either, it is
The steps for processing are as follows: possible to replicate the classic scheme:
1. At least two microphones are set up: 1. Whichever piece of the drum kit is getting
close mic(s) (to pick up the hit itself) the effect will need at least one
and ambience mic(s) (to pick up microphone set up close to it. Ambient
ambient sound). Usually, there is also microphones are unnecessary but can be
a stereo pair involved that captures used if desired. The sound can be
the overhead stereo image or achieved in acoustically "live" or "dead"
cymbals. rooms, since all reverberation will be done
2. The whole drumset and all mics are inside the effects unit processor.
placed in a very live room (i.e., one 2. The close mic sound is fed to the
with huge amounts of reverberation reverberation unit, then optionally to a
and particularly early reflections from compressor, and then to the noise gate's
its walls, ceiling and floor). signal input.[14]
3. High-gain compression is applied to 3. The same sound from the close mic is fed
ambience mic(s) to capture the quieter to the noise gate's key input.
details of the reverb sound. (optional) 4. The "wet" and "dry" sounds (which is to
[14]
say the processed and unprocessed
4. Ambience mic(s) are fed through a sounds, respectively) can be mixed to
noise gate with separate external key taste.
input. This setup does not require a "live room" to
5. Close mic(s) are used as an external achieve the enhanced reverberation of the drum
key for the noise gate. sound and therefore the effect can be
6. Hold time of noise gate is set to half a reproduced at live gigs without great difficulty.
second or so (this would be a real
duration of hit sound), followed by a
fast release time. This causes the
gate to allow only the first half-second
of reverb to pass through after each
drum hit, before closing again.
7. close mic and ambience sounds are
mixed to taste.
This results in a very live-sounding drum that
is rapidly cut off with none of the
overpowering secondary reflections
associated with reverb.
