Basic knowledge about “Reverb"

The oldest natural effect we have is reverberation.

We use it to mimic the natural sound reflections in physical spaces, halls or chambers, but the creative potential of reverb can be greatly expanded when used in conjunction with other effects to create immersive soundscapes.

By adjusting parameters such as reverb time, pre-delay and diffusion, we can manipulate the size and character of the virtual space in which the sound appears to float. For example, a gritty spring reverb can add a vintage touch to a guitar riff, or a shimmering granular reverb can envelop a synth pad in sparkling, crystalline reflections.

Natural reverb consists of three elements:

1. Direct sound: It reaches the ears without reflections from surfaces.
2. Early reflections: They occur shortly after the direct sound and influence width, localization and spatial character.
3. Reverb: The unified late reflections create the long-lasting decay. The intensity decreases gradually, depending on the room size, materials and treatment. Digital reverb effects offer possibilities that are not possible in the real world.

Story:

The reverb effect is one of the oldest guitar effects and was already used in the 1960s as a spring reverb in amplifiers such as those from Fender. In the past, the control options for spring reverb were limited to an intensity control, with no options for setting the room size or reverb duration. Today, guitarists use studio-quality digital reverb pedals as stomp boxes to integrate the popular reverb effect into their guitar playing.

Typical controls on a reverb pedal:

• Ratio: Determines the volume ratio between the direct signal (dry signal) and the reflected signal added by the effect (wet signal).
• Decay Time: Describes how long it takes for the reflected sound to decay to an inaudible level. This time period provides information about the size of the simulated room.
• Pre-Delay Time: Is the time period between the start of the direct signal and the entry of the wet signal. It reflects the distance between the instrument, the reflecting surface and the listener.
• Tone: Higher frequencies, which have less energy, are absorbed by the environment more quickly than lower frequencies, making the effect sound darker and warmer than the original instrument. To achieve a balanced and realistic sound, high-quality reverb devices often have a tone control.

How does a reverb effect work?

For guitarists in the 1950s, reverb was a phenomenon created solely by the acoustic space in which the guitar was played.
In the studio, reverb was only created through complex processes. Either you had to use a large room to get the necessary reflections, or you sent the signal into an echo chamber - a room with stone walls in which a loudspeaker was placed in a corner.
By using one or more microphones at a significant distance from the loudspeaker, the signal was recorded, including the resulting reverberation reflections.
Even a plate reverb was not mobile at that time: an electronic converter transferred the signal to a metal plate, which was then made to vibrate. The electromagnetic signal was then converted by a pickup into an audio signal, which was then mixed with the original signal.
The reverb spiral, first used in Hammond organs and later integrated into the portable Fender Reverb Unit of 1961, provided a convenient solution. The way a reverb spiral works is similar to that of a plate reverb:
The guitar signal is sent through a converter into the reverb coil, which is set into vibration by the attack signal. At the end of the reverb coil, the processed signal is tapped and mixed into the original sound.

There are different types of reverb effects, which can be divided into analog and digital reverbs as well as into different modes or types of sounds. These distinctions can be traced back to the manufacturing and technology of the effects devices.

Each of the basic reverb modes can be created either analogically or digitally, creating a variety of tones that need to be distinguished.

Starting with the classic room reverb or room hall : The analogue or natural version of this effect is created by simple spatial sound reflections. Special echo chambers are designed for this type of sound generation.

Digital reverb pedals reproduce this sound using digital circuits that recreate room reflections using echo algorithms. They are similar to digital delay effects.

A spring reverb is created analogously by a reverb spiral, as can be heard in the classic sound of the Fender Reverb Unit, for example. Digital pedals also try to artificially emulate this reverb.

A plate reverb is created by the vibrations of metal plates and, like other types of reverb, is simulated by digital circuits.

A shimmer reverb is a reverb effect that typically adds a high octave to create a "shimmering," angelic sound. Over the last decade, this effect has gained enormous popularity, especially in the ambient, indie, and post-rock genres.

The AMP1 's digital reverb is modeled on a classic spring reverb. It's particularly suitable for traditional clean sounds. A little reverb is also recommended when practicing, especially with headphones.