Whenever we hear a sound, we're actually hearing a combination of two distinct elements: the original source of the sound and the space around it. For example, if the same violinist were playing the same violin in a practice room, a concert hall, and a cathedral, the player and the instrument would remain essentially the same. However, the experience of hearing that music would differ greatly because the practice room, concert hall, and cathedral each have unique acoustic properties.
While the instrument itself remains unchanged, the space around it varies, affecting what we perceive as reverberation or "reverb" for short. Reverberation is all about how sound moves within a space and bounces off its surfaces to reflect or reverberate certain frequencies within the sound being played.
Reverb can be conceptualized as many individual echoes. When a sound travels from its source into a room, it spreads in all directions: left, right, up, down, front, and back. As this energy disperses throughout the room, it begins to fade. The initial echoes reaching the listener are the loudest since less energy has been lost at that point.
However, with each successive surface an echo bounces off, more energy is lost, leading to decreasing volumes for each individual echo. Reverb consists of a large number of these reflections, and we don't hear each one separately. Instead, we perceive a cloud of echoes, lasting until the sound energy has completely dissipated.
The characteristics of reverb can vary significantly depending on the room's size, shape, and the materials it's constructed from. Record producers and mixing engineers often experiment with reverb in pursuit of new sounds for their records, just as they experiment with the source sounds.
You might already know that recording studios are typically acoustically treated to minimize reverb reflections. Producers do this because they want the flexibility to add the precise type and amount of reverb to the sounds they record during the mixing stage. If a sound is recorded with room space as part of the source, it becomes challenging to remove it cleanly, thereby limiting what can be done with that sound later on.
That's why individual instruments, especially vocals, are almost always recorded in spaces where reflections can be minimized. Sometimes, however, the sound of a particular space is a reason to record there. For example, Abbey Road Studio One is a popular choice among film composers due to its unique acoustic properties, and its reverb has become legendary in film soundtracks.
In conclusion, when making recordings, it's essential to consider whether you want to minimize reflections for maximum flexibility later on or seek creative spaces to record in, allowing the natural acoustics of that space to become a part of the sound of your mixes. Your choice will significantly impact the character and quality of your final product.