Reverb is an echo effect reminiscent to sound you get when you are overlooking a canyon and can’t resist the urge to shout “hello” and hear it echo back at you. This probably makes reverb one of the first know sound altering effects to man. If you want an example of reverb turn the reverb knob all the way up on your guitar and strum it. Immediately deaden the strings with your hand and you should hear the echo reverberate from the speaker.
In the early days of recording reverb was done in different ways. One way was to place a microphone at one end of the room and another close to the speaker cabinet. You would then record the guitar on two tracks and play them back together giving a sort of echo effect. If the effect needed to be tweaked or changed the engineer would move the microphones or speakers around the room until the desired effect was achieved. Another way of achieving reverb is to place the microphone and amp in a bathroom. We have all sung in the shower before and thought we sounded pretty good, right? Bathrooms are small rooms usually with hard walls that reflect sound instead of absorbing it. I have read articles on bands that still record their albums like this today.
There are many units available today that recreate multiple environments for reverb. The Alesis MidiVerb4® is an example of one of these units. It lets you sound like you are playing anywhere from a stadium to a closet and anywhere in between. I use this particular unit mostly for vocals and acoustic guitar. It can be used effectively on electric guitars, bass, drums and keyboards also.
There are many types of reverbs that you may run across in your search for the best sound for you. Two of the most common are spring reverb and plate reverb. I am not going to go into the differences right now but if anyone wants to know more about them let me know.
Note: As a general rule of thumb to little reverb is always better than too much. To much reverb in the mix can make the sound muddy and drown out vocals and other instruments.