Reverb is a common 'effect' that you hear all the time in everyday life! Reverb is created by sound waves reflecting off surfaces, usually in a confined space. I'm sure most people will have been in a church or hall where the footsteps or claps can be heard well after the sound was created. The sound waves are bouncing off the surfaces and you hear these reflections after the principle sound and that is what gives the reverb effect!

Our brains are used to hearing these reflections in real life and so adding them artificially to recordings makes us perceive the sound to be coming from a certain environment which is a very emotive and powerful music production tool.

Reverb effects try to emulate natural reverberation to make a bigger, atmospheric, ambient sound by adding the illusion of space to an instrument’s tone. Control of reverb is essential when recording, either by exploiting a space for its particular natural acoustics or by deliberately dampening the studio environment - e.g., through foam padding and other absorbent materials - to remove as much reverb as possible. We talk about a lack of reverb as being ‘dry’, in comparison to a ‘wet’ sound with lots of reverb, either through a natural sound or by adding effects. As with all effects, the different types of reverb can be used subtly or in an exaggerated way to achieve certain results.

The history of reverb and delay effects are interdependent - the first tape echo machines were intended to create a natural reverb, not necessarily a delay/echo effect, and delay pedals can be used to create a similar ambience/space to reverb. However, let’s look at units specifically designed for reverb alone.

The main ways of adding (artificial) reverb to your sound are by:

Using an amp with built-in reverb, such as a Fender Twin Reverb
Using a designated digital reverb effects pedal or reverb settings from a multi-fx
Using reverb effects in the studio - either analogue plate units or digital emulations.

Reverb Types

Because reverb is a naturally occurring 'effect' the types of reverb often have names that describe the space that they replicate, although there are common 'artificial spaces' as well which are named after how they are created.

Room
Room reverbs replicate the natural sound reflections one would find in a room. The reflections in a room are usually quite short and will have different characteristics depending on the room shape. Great recording studios (like Ocean Way or Abbey Rd) have rooms (spaces) with beautiful natural reverb which is sought after and one of the reasons people will pay a lot to record there.

Hall
Hall reverbs are similar to Room Reverbs but bigger! Usually with longer reverb times and possibly different 'shaped' frequency spectrum, depending on the space being replicated. Concert halls with 'designed' natural reverb are often emulated but your school hall probably isn't!

Cathedral / Stadium / Chamber
The names of these reverb types are letting you know what the reverb sounds like. A Stadium reverb often has a large pre-delay (a gap before a reverb starts), a Cathedral usually has a lot of reflective stone surfaces and is very dense - just listen to a few of them and you should get the idea.

Spring Reverb
Spring reverb is an artificial reverb created by springs in a box! It is the most common type of reverb found in tube guitar amplifiers!

Plate
Plate reverb is another artificial reverb created by a metal plate suspended in a large (often wooden) box. When a sound is fed to the sheet via a transducer, the metal plate vibrates and creates an effect very similar to the way that we hear reverb naturally. These vibrations are picked up with small pickups and fed back in with the main signal. One of the most popular (and my personal favourite) is the EMT 140.

Reverse
Reverse reverb is a digitally altered reverb where the reverb effect is reversed and gives a very unnatural (but sometimes very cool) sound.

Gated
A Gated reverb is one that stops suddenly rather than fading out naturally and was used a lot (more commonly on drums than guitar) in the 1980's.

History

Initial studio approaches to reverb were limited to working with (or trying to control) the room that a live performance was being captured in. The first ‘creative’ use of reverb (the studio bathroom!) on a pop record is credited as being The Harmonicats ‘Peg O’ My Heart’ (1947). However, what studio engineers were after was a system where reverb could be added - and controlled - to a dry recording.

This came with Plate Reverb - essentially a vibrating metal plate in a box - was introduced in 1957 by German company EMT, and became a popular way to create reverb in the studio. However, plate reverb technology is impractical to take on stage, and so the next breakthrough was in the creation of spring-based systems built-in to guitar amplifiers.

Spring Reverb was invented for use in Hammond Organs in the 1930s and went on sale in the 1940s. The first compact reverb effect was created by a division of the Hammond Organ Company which became known as Accusonics. Their Type 4 Spring Reverb unit (1960) was so successful that it was licensed to other users - one of the first customers was Fender, who incorporated the Type 4 in, for example, their Twin Reverb (1962) and Vibroverb models (1963).

Separate, outboard reverb ‘tanks’ such as Fender’s 6G15 standalone reverb (early 1960s) allowed guitarists using other amplifiers to exploit reverb tones.

Digital Reverb effects emulate hall (large room/space), room, plate and spring reverbs either in stomp boxes or rack units. The first digital reverbs were studio bound, e.g., EMT 250 (1976) and Lexicon’s iconic 224 (1978).

The next step towards portability for guitarists were Analog Electronic Reverb Pedals. For instance, Morley emulated a spring reverb with analog electronics with their Rock’N Verb (1980). Later refinements include the DOD FX45 (1985) and the Arion SRV-1, released around the same time.

However, the big breakthrough as far as modern reverbs for guitarists came with Digital Reverb Pedals, introduced in 1987 with the Boss RV-2. There are now countless models on the market, all offering their own spin on the same principles: that of replicating natural reverbs (often grouped as e.g., Church, Hall, Room type sounds) and the character of mechanical reverbs (plate and spring).