Reverb is used to create atmosphere and depth (back and forward, more pushes the sound back, less puts the sound in front of the sound space). Reverb is a complicated and creative tool. Reverb is usually best placed on a bus channel, and then you can send parts of each channel to the same reverb using the FX sends. This will save on processing power and mean all your sounds appear like they are coming from the same space. Power Tip: To get your reverb setting in time with your track, dived the 60,000 by the tempo, Then either use that number or divide by 2. So a tempo of 140 = 60,000 / 140 = 428 or 4.28 (milliseconds).
You can either use that setting of 4.28 but usually that will create to much reverb for dance music, so a shorter snappier setting of 2.14 (ms) (half of 4.28) will work better. That number is applied to the ‘reverb time’ setting, and will mean that the reverb tails fall just in time for the next sounds. This is very handy in nearly all production. I would tend to EQ the bus were the reverb is (after the reverb plug in) using a low shelf starting at 360hz down to 20hz at about 4db reduction. This will remove any muddiness to the reverb and clean up the overall tone of the mix a little. Using automation on reverb is also a favorite, can be used very creatively, especially in the 16 bar fills and before the drop to create massive sounds, try using this technique on a reversed symbol before the drop, followed by a clean normal cymbal on the 1st beat of the 1st bar of the track. You can also use reverb in reverse on a vocal to create a space aged effect. First reverse the vocal, then add reverb, then reverse the vocal again, so it plays normally.
Reverberation is important because it gives a sense of space. For live recordings, there are often two or more mics set up to pick up the room sound, which can be mixed in with the instrument sounds. In recording studios, some have “live” rooms that allow lots of reflections, while others have “dead” rooms which have been acoustically treated to reduce reflections to a minimum – or “live/dead” rooms which may have sound absorbing materials at one end, and hard surfaces at the other. Drummers often prefer to record in large, live rooms so there are lots of natural reflections; vocalists frequently record in dead rooms, like vocal booths, then add artificial reverb during mixdown to create a sense of acoustic space.
Whether generated naturally or artificially, reverb has become an essential part of today’s recordings. This article covers artificial reverb – what it offers, and how it works. A companion article covers tips and tricks on how to make the best use of reverb.
Different Reverb Types
There are two main types of artificial reverb: Synthesized and convolution-based. Synthesized reverb “models” the sound of a room through the use of various algorithms. For example, a “Hall” algorithm will take into account that waves travel further in a concert hall than in a small room, so the reverb will take longer to decay. A “Room” algorithm might model a small room, like a club or practice space. Other algorithms model artificial reverbs, such as “Spring” reverbs found in guitar amps, or “Plate” reverbs that were used extensively in the 60s. Each algorithm has a different sound quality, but they all work in the same basic way: A signal comes into the reverb, is analyzed, and the reverb algorithm generates echoes and reflections that mimic what happens in the chosen acoustic space.
Convolution reverb is a relatively new type of technology that “samples” the sound of a room. Typically, adevice like a sports starting pistol will create an impulse that creates reflections in a room. These reflections are recorded, analyzed, and converted into a very accurate model of that specific room. A good analogy is that a convolution reverb’s impulse is like a “mold” that you pour sound into, and the sound acquires the characteristics of being in that room.
You can think of the difference between synthesized and convolution reverb as the difference between a synthesizer and a sampler. The synthesizer will give more control over the sound but have a more “impressionistic” character, while a sampler provides an extremely accurate, but generally less editable, sound.
Another consideration is that convolution reverb is a very processor-intensive operation. Only recently have computers become powerful enough to allow for real-time operation, and even then, you might experience some audible delays due to processing. Fortunately, as reverbs are based on delays anyway, with fast computers you might not notice anything objectionable.