Some time ago I wrote this article for hiphopmp3 site and I thought I could share that on my blog as well. So what exactly is reverb? I do not want to go into the meaningless definitions, because anyway the most important is to know how to use the reverb rather then the most polished definition. But to give you some context I will try to summarize that in the next paragraph.
The reverb is trying to imitate that we encounter daily. Every sound we hear is composed of the initial signal and the signals that are reflected somewhere in the area and being continuously reflect further. The overall feeling, that comes natural to us, actually shows us the characteristics of sound environments. In a stone cathedral or in a small room with wooden furniture, every sound will sound slightly different. Studio reverb is trying to emulate such environment, and therefore reverb has usually many different settings, from the material characteristics, over the amount of space to the absorption and reflectance of various materials and filters. The aim is to fool our ears and give the impression of listening it in a selected environment.
The main types and settings
Types – this includes usually a great hall, small room, plate, reversed, gate type of setting. Just characteristics of the environment, reflective material, etc. Great Hall is mostly used when we want an instrument to move from foreground to background, to create the impression that the instrument is playing from a greater distance. Plate reverb is used mostly on the drums (especially snare) and vocals (for solo usually a little bit less than for accompanying vocals), the sound is more pronounced and usually quite colored. Gate reverb is a reverb, which is interrupted by an optional setting, it is used often for its aggressiveness on percussion.
The main settings
Pre-delay – It is the time at which the reverb is recognizable and is set in milliseconds (20ms, 60ms…) It’s a good way to achieve a larger space, and used mainly on vocals.
Reverberation time (decay) – Some materials reflect more, some less. Reverberation time determines how much the original signal will still reflect and still be heard, until it drops below -60dB over the original signal. Long reverberation time works well on some strings and piano with the sustain pedal passages. Reverberation is important to align with the tempo and rythm – some sounds, especially in faster BPM songs, fit well with a short reverberation time, while the long reverberation time on vocals can be effective.
Frequency characteristic (cut-off at higher frequencies) – a certain environment reflects the frequencies differently. For example, wood-paneled room will reflect the best the mid-range frequencies, while the bottom spectrum will absorb more. Higher frequencies have a shorter reverberation in nature. Frequency characteristics can modify their behavior and thus add reverb to our credibility. Sometimes it is sufficient to connect an EQ on the signal and adjust those frequencies that does not fit well with the overall mix.
In addition, there may be settings as ER – early reflections, diffusion, stereo – separate channels, mono EQ, wall, reverse, etc. Most of these settings simulate environments, such as the wall sets the position of walls in space. It depends on the particular reverb hardware or software and it is therefore good to read the manual. Personally I usually simply upload and edit preset key settings as needed. It is hard to catch up the minor differences anyway in your home studio.
Today there are more or less no rules for applying reverb, reverb can be used both on track to achieve a certain compactness (mastering reverb) and the individual channels as required. Previously, the reverb was set through the send connection in order to take advantage of the mixer’s routing features. In this case the main signal was mixed with the reverbed signal. This connection preserved performance in the digital mix of the old engines, because one reverb was used on multiple channels. This problem is eliminated with the increasing power of moder computers and therefore the reverb can be connected directly to the signal. But keep in mind that it is important to keep the correct wet and dry mix settings (most programs already sets this up for you automatically). For direct connection, Dry mix is on 100% and Wet mix is incorporated, as appropriate, while for routing connection, Dry is on 0% and Wet on 100 % – the amount of reverb in the mix is then set by adjusting the loudness of the routed signal. Routed connection has also other benefits, namely the possibility of further modification of the reverbed signal. For example by using EQ, phaser and other stereo engines, changing panorama etc. Moreover the original signal can be further edited by the compressor etc. Pretty good trick is to use a chorus instead of the piano or synth just to the reverbed part of the signal to achieve very interesting rich sound.
Today’s digital reverbs are also already equipped with MIDI, so you can change individual parameters during the song. For example, you can dramatically change the reverb in the transition from one part to another.
Reverb is, in my opinion, one of the most important effects at all and I can not imagine the work without the use of reverb. With a little experimentation you can achieve a really interesting sound effects. But please note that excessive use of reverb can made your record messy. Improper use of reverb or too large and long reverb can ruin the whole song.