Reverb falls into categories and while there is a little variation between manufacturers. For example, some draw a distinction between a Hall and a Church, broadly speaking we are typically dealing with a choice between the following:
Room
Hall
Chamber
Ambience
Plate
Spring
Non-Lin
While there aren’t rules as such it’s common practice to use more than one reverb in a typical music mix. A short bright reverb for percussive sounds and a longer, darker reverb for vocals is typical. What about those other elements of your arrangement? Do you have a first choice when it comes to reverb type?
How Do Reverb Types Differ?
Room
You’re unlikely to find a definitive description for the characteristics of a room reverb and if you do you should probably approach it with caution because “room” is a broad category. How a room sounds depends on what kind of room it is and a small bathroom isn’t going to share many characteristics with a large office but they are both “rooms”.
The core of a good room reverb is the balance between an appropriate series of early reflections to give spatial cues about the size and shape of the room balanced against a suitable tail to give information about the nature of the surfaces in the room.
Rooms are the broadest category and with enough skill and range in the controls, a room algorithm can create any acoustic reverb.
Hall
Halls have a low initial density, with a slower build-up of reflections than in a typical room. They have distinctive cluster of early reflections which are more widely spaced than in most reverbs due to the size of a typical hall. The reverb tail tends to be longer and the volume of air through which the sound travels between reflections contributes to an HF roll-off in the tail giving a darker sound.
Chamber
Chambers have a rapid build-up of reflection density, bright without the HF roll off of a hall. Short, bright and dense these reverbs are perfect for busy arrangements where a hall would muddle more than help.
Plate
Up until this point, all the reverbs in this list are simulations of naturally occurring reverb - Simply put that would be sound travelling through air and bouncing off solid objects. The next two examples are fundamentally different in that they are based on the effect of sound travelling through metal. This is a distinction made very apparent in Liquidsonics’ Illusion plug-in, in which the choice of algorithm is between an environment (a physical space - air surrounded by walls) and a plate - a sheet of metal suspended under tension.
Air is unusual in that all frequencies travel through it at the same speed. Sound waves travel through metal at different speeds and this dispersion effect gives plates a very distinctive sound, with a lag in the low frequencies which increases as the frequency falls. The decay differs too as the best plate algorithms simulate the effect of the felt dampers used to physically absorb the vibrations in the plate.
Spring
The poor relation of the plate, tensioned springs replace the plate for a much more cost-effective and compact solution in the days before digital reverb. All but the very best sound pretty nasty but they are invaluable for vintage electric guitar tones.
Ambience
A variation on the room reverb, Ambience programs favour the early reflections to such an extent that the tail is often absent. This use of just early reflections gives spatial cues and the impression of increased distance without the clutter of a tail and as such sounds very dry.
Non-Lin
In nature, the rate of decay of reverb is consistent over time (i.e. linear). In Non-Linear reverbs, the tail is abruptly cut off giving the popular gated reverb effect.
Take Our Poll
What is your go-to reverb type? Room? Hall? Plate? Maybe Chamber? Vote in our poll and share your thoughts about which reverb you use to create that effect in the comments.
Historical Development Of Artificial Reverb
When considering the different reverb types it’s difficult to separate them from the era with which they are most commonly associated. Reverb, as with so many things is a story of technology and fashion.
For an excellent and very digestible potted history of reverb check out this article from Universal Audio in which Daniel Keller traces the use of reverb in recording from the early post war period to modern digital reverb.
For more detail and some examples check out UA’s blog post but the timeline runs something like this:
Pre 1947 - Mic Placement
More or less of the natural reverb of the space in which the recording is being made can be exploited by placing microphones closer or further from the source being recorded. As more microphones are introduced in to the recording process greater control is possible. When recording with a single mic the balance between players could be balanced by moving closer or further from the mic but this inevitably introduces more reverberant sound from more distant instruments.
1947 - Echo Chambers
Once multiple microphones are paired with mixing consoles the possibility exists to send groups of signals from the console to a speaker in a very reflective room. Microphones capture the reverb of that space and bring it back to the console in the first example of an effects loop.
1957 - Plate Reverb
EMT release the first plate reverb. This large, heavy enclosure containing a tensioned steel plate is small and cheap compared to a real chamber. Luckily they sounded good too and they remain popular today, though usually in digital form.
1976 - Digital Reverb
EMT release the EMT 250, shortly followed by Lexicon in 1978 with the 224 and by 1981 with the AMS RMX16 reverb was now digital and some of those massive reverb tails from the 1980s are probably still decaying away…
For another take on this timeline with some good info and nice pictures try this article from iZotope.