Ever wondered what all the preset names on reverb plugins actually refer to?
Room / Hall / Chamber: The first reverb effects used for recorded music were created with echo chambers – a loudspeaker would play the sound back in the chamber, and a microphone would pick it up again, including the echo of the room itself. The same principle still applies for simulated ‘room’ and ‘hall’ reverbs -you’re capturing the ambience of a particularly sized and shaped space.
Plate: Next came plate reverb with the EMT 140 in 1957. Used a lot in the ‘60s and ‘70s, plate reverbs use a transducer to create vibrations across a large ‘plate’ of sheet metal. A pickup captures the vibrations as they bounce across the plate, and the result is output again as an audio signal. Plate reverb tends to be bright and clean-sounding, and it holds a special place in many producers hearts.
Spring: Uses a similar principle to that of plate reverb, but with a metal spring instead of a plate. A transducer at one end and a pickup at the other are used to create and then capture vibrations within the spring. Being compact and relatively cheap to manufacture, many guitar amp designs ended up incorporating a spring reverb unit. Spring reverb adds a distinctive metallic colouration to the sound, and in the days of classic rock ‘n’ roll it was known that you could shake the reverb cabinet while recording so that the springs clashed together for a properly unhinged sound. We wouldn’t recommend attempting this with a plugin version though 🙂
The UAD EMT 250 plugin faithfully models the levers of the original hardware, allowing you to control your reverb in the same way as you might fire the Death Star.
Digital: EMT built on the popularity of the EMT 140 plate reverb with another world first in 1976: the EMT 250 digital reverb unit. However, it was the arrival of the Lexicon 224 a couple of years later, followed up by the 480L in 1986, that took digital reverb into virtually every professional studio, and it’s the Lexicon name – and sound – which is now cemented in our minds as the archetypal digital reverb of the 1980s. Since then, we’ve also seen many highly-regarded and much-loved digital reverb units and guitar reverb effects boxes from the likes of Eventide, TC Electronic and Yamaha, such as the Eventide Space pedal, TC Electronic Reverb 4000 and most recently, the Bricasti M7 rack unit. Meanwhile, the awesome Strymon Big Sky has virtually taken over the world of guitar reverb.
The Difference Between Algorithmic And Convolution Reverb
Almost all reverb plugins (as well as hardware digital reverb units) use one of these two digital processing methods.
Algorithmic reverbs use calculations based on hypothetical rooms and other spaces to generate their reverb sounds. Generally this gives a sharper, more artificial sound, typified by most hardware digital reverbs of the last 30 years. This is not necessarily a bad thing though – as mentioned above, musically we’re not always after the most ‘natural’ sound, but the one that has the right ‘character’ for the track. Algorithmic reverbs also tend to be far lighter on the computer’s CPU than convolution reverb processing.
Convolution reverbs use pre-recorded samples of real rooms and spaces to build Impulse Response (IR) files of those spaces. The impulse response is then ‘convolved’ with the incoming audio signal you want to process, hence the name.
Convolution reverbs then, are generally far better at simulating real spaces than algorithmic reverbs – the downsides are that they also require significantly more CPU processing power to work, so you are more limited in terms of the number of instances of the plugin you can run simultaneously, and they often require a bit more work than algorithmic reverb to sit comfortably in a mix.
Recent Developments: Emulations & Future Reverb
In recent years, we’ve seen a surge in the popularity and innovation going into a new generation of algorithmic reverbs, often based to a greater or lesser extent on the Lexicon 224 and 480 digital hardware units as a gold standard. We’re also seeing progressively more accurate and accessible plate reverb emulations, often using the EMT 140 plate as the benchmark for having the most legendary mechanical plate reverb sound.
Happily though, it’s not all copies of hardware: we’re also starting to see a greater range of more unusual and forward-thinking reverb plugins, led in many ways by 2CAudio’s Aether and the Valhalla DSP range, but now also joined by a new wave of next-generation reverb plugins such as Waves H-Reverb, UVI SparkVerb and fabfilter’s Pro-R. With these, premium sound quality is a given and the focus for new and improved designs is now as much on usability, a fast and smooth workflow, and cleverly-implemented visual representations of the effect as you adjust the controls, so that you can sculpt your ambience with new levels of speed, precision and detail.