denise audio breaks down the technical details behind plugins and helps you understand how they really work. This blog post focuses on the mystery behind plate reverbs. What are they? Well – read on to find out exactly how they work, including some history, audio examples and a technical description from denise’s plugin developer.
Reverb Hardware Unit Eventide H3000
Reverb is the name we give to the phenomenon of sound continuing in an environment after a sound has been produced. In real life, we can easily appreciate it in big halls or churches – but in the studio, for example, there are many different technologies to help recreate this extraordinary effect, ranging from old school echo chambers to modern digital processors.
A plate reverb is called the way it’s called because it is simply a device that consists of a big sheet of steel. The audio signal gets boosted by an amplifier that sends it to the transducer in the middle of the plate, which consists of a coil and a magnet that make the metal vibrate to the input sound. You can see it as a big speaker with a metal cone. A dampener is used to achieve shorter reverb tails and the vibration gets recorded by using pickups that go back to an amplifier that balances and boosts the signal on the way back to your studio gear. As opposed to echo chambers / room ambience, it creates a lush fictional color that our ears immediately perceive as unreal, and countless engineers consider the sound unique, making it iconic. A big role in it’s distinctive warm and resonant sound is played by the precedence effect, which makes the higher frequencies arrive to the ears faster than the lower ones, making it bright at the beginning of the tail while it darkens along the rest of the decay. It can go from very immersive with long, sweeping tails to snappy with short resonant tails.
Before plates, reverb in recordings would only be possible by performing in big halls or by using expensive studios which would have a separate echo chamber which is a reflective room where loudspeakers would be placed and the natural ambience would be sent back to the mixer (Check out this clip to hear the first record to use a reverb). A mechanical alternative would be spring reverbs, built in Hammonds and guitar amplifiers, consisting of sound literally passing through a spring. These sounded cheap, lo-fi and artificial.
When the Berlin-based company Elektromesstechnik (EMT) produced the first plate reverb in 1957, the EMT 140, it was game changing! (EMT are still active and are currently producing turntables). It was much more practical than using a whole room, and it was adjustable, making it perfect for studio recordings. But first of all the sound that it produced was unique: warm and thick, not as natural as an echo chamber, but it definitely had its own “supernatural“ charm that made it famous on thousands of records.
The new reverberation unit became a standard and was released 3 years before the great shift of the recording industry from mono to stereo.The limitations with reverb in mono were related to the phenomenon of frequency masking: that psychoacoustic phenomenon that happens when different sounds stack up in the same frequency range, making the instruments hard to distinguish and creating muddiness. Think of Phil Spector’s wall of sound (you can hear a great example on “Ike & Tina Turner – River Deep Mountain High”), powerful but very out of focus and muffled.
As this new piece of gear was introduced during the shift from mono to stereo recordings, which became a distinctive trait of the best productions from the 60s on. Alan Parson’s only reverb on the whole of Pink Floyd’s “The Dark Side Of The Moon” was Abbey Road’s EMT 140 plate reverb. It had already featured in all productions coming from the same iconic studio; The Beatles included. And in the USA it was used at the RCA Studio B in Nashville (cradle of the famous “Nashville sound”) and at the Hitsville USA in Detroit (Did somebody say Motown?).
As technology developed over the years, with digital reverbs of many kinds replacing most of the mechanical stuff (EMT themselves put out various digital plate models, legendary units that utterly revolution the production), plates still find their way on contemporary productions: vintage plates, contemporary diy versions, or digital emulations, nothing can quite replace the dreaminess of a lush plate reverb or its snappy resonance.
Money – Pink Floyd
Listen to how the very wet drum track complements the very dry bassline, or how the guitar solo’s reverb sounds thick and warm, very present but never overwhelming.The reverb is mastered to create different sonic spaces, helping the song sections tell a story, for example listen to how the instrumental becomes suddenly dry at 3.50 and then at 4.20 the plate is used again to create depth and drama.
Thank You – Led Zeppelin
The instruments here sound like they have been feeded into differently tape-delayed reverb plates, achieving different depths for each instrument. That’s how you would do pre-delay!And while the gtrs have a shorter dampening setting, the decay on the drum track’s plate is way longer.
Micheal Jackson – Thriller
Bruce Swedien used a prototype of “Ecoplate” reverb by Jim Cunningham, built exclusively for him. The idea was to improve by building the plate out of stainless steel.You can hear it all over Thriller and Off The Wall, as a main reverb.
Sohn – The Wheel
The whole lead vocal line here sounds stunningly deep and warm. This whole masterpiece would definitely sound completely different with another reverb sound.
There are basically two techniques to create a plugin that emulates a traditional plate reverb: convolution with a plate IR (impulse response), and modelling the plate sound algorithmically with a structure of feed-backing delays. When using convolution, you can create a very natural emulation by using an IR signal created with a real plate reverb. However, reverbs using IRs are generally very limited in functionality – one IR just recreates the plate at a single setting at a time. When using the algorithmic approach, you can add a lot of flexibility to a plugin. Other challenges arise though with the algorithmic approach, as it is hard to avoid the ugly metallic and resonant sound that feed-backing delay units produce and to design a structure that mimics the exact behaviour of a traditional plate. Getting it right algorithmically is hard, which is the reason that most companies developing reverb plugins do not disclose their exact methods.
Plate reverbs are great sound design devices. You can go from sparkling metallic sounds to deep and dark resonators. Tape saturation is usually a great compliment for making it thicker, and more in general, pedals or extra effects create amazing results too. Experimenting with various materials (if you are going for a real one) and dampening settings (if you use plugins) you can produce very different kinds of decays that can dramatically twist your workflow and become crucial to the shape of your own sound.
Written by Enrico Tiberi (nrec)
Additional writing by Jochem De Jong (JD)
Sub edited by Joe London
Try the Perfect Plate or the Perfect Plate XL for free for an unlimited time. Download it now: https://www.denise.io/store/denise/PerfectPlate