Whether you prefer a sprinkle or a soaking, reverb is the master of all musical effects
Long before digital simulations became sophisticated enough to blur the lines between actual and artificial ambience, studio engineers and electric guitarists were obliged to use springs, specially built chambers and plates. The reverb characteristics these devices produced may have had technical shortcomings, but the characteristics were often so strong and sonically pleasing that they became integral to the sound of recorded music in the post-war era.
Room-inations
The terms echo and reverb were once used interchangeably. By and large, we associate echo with shouting a word into a large reflective space and hearing our voice bounce back at us multiple times, a second or so later. Reverb is created by multiple soundwaves bouncing off hard surfaces, so ‘echo’ isn’t entirely incorrect. However, the reflections are so close together that they create continuous sound that gradually dies away. When the time-lapse between the initial sound and the reflected sound is sufficient for both to be heard separately and distinctly, the accepted term is ‘delay’.
Reverberant spaces tend to be those with hard surfaces that reflect soundwaves. You will have noticed how a bathroom with a tiled floor and walls sounds very different to a carpeted living room with lots of soft furnishings. If you haven’t, then grab an acoustic guitar and try playing in both. Similarly, stairwells, churches, sports halls and cathedrals tend to be reverberant.
When designing concert halls, recording studios or public spaces, acoustic engineers consider the RT60. This is the amount of time it takes for the level to drop by 60dB, and it can be manipulated and controlled to optimise the acoustic environment for any specific purpose. In a lecture hall or a talk-radio studio, speech intelligibility is paramount and reverb is best kept to a minimum. But if you’re singing or playing a musical instrument, a bone-dry acoustic is uninspiring and unhelpful. This is why concert halls and venues generally retain some degree of ambience.
But recording a large number of musicians simultaneously in a single room is one of the great challenges of studio work. If the room is very reverberant it becomes even harder to achieve clarity, separation and a coherent stereo image because the microphones will be detecting reflected sound along with the direct sound. Also, if you record natural room reverb, you’re stuck with it. This is why recording studios tend to have carefully controlled acoustics, and many engineers prefer to eliminate room ambience when recording and add reverb effects later in the mix.
UA’s Bill Putnam is credited with the first use of a reverb
