By Justin Joseph Hall
Behind the scenes of “Abuela’s Luck” by Ricky Rosario. Photo by Daria Huxley.
Echo and reverb are almost the same audio effect except for one variance, and that’s time. Reverb and echo are reflections of sound in a space. However, echo is the more common word and we know it as hearing a reflection of sound return to one’s ear quieter and later than what was said. Famously on television people shout into a canyon and hear what was said shortly after in fading repeats equally distant apart in time.
Reverb is the same concept as an echo but with a smaller reflection time that often comes back within a second and conflates with the sound that hasn’t finished yet. For example, If I were to say, “I would like to hear my echo,” and applied an echo effect through some software, I might say the entire sentence and then hear the entire sentence back. However, if I said the same thing and applied a reverb effect, you could start hearing the effect before you get to the second word of the sentence. This replicates what it sounds like to hear reflections of sounds from rooms with hard walls.
In some cases in real life, you may hear reverb and echo when short sound reflections (reverb) and longer sound reflections (echo) hit your ear simultaneously. For instance, when you’re in a racquetball court, you are likely to hear the reflection from a nearby wall quickly, but the far wall may take a bit longer to reach your ear. This kind of room creates a fun interplay of reflections. Many rock songs from the 1980s famously use these kinds of combinations to create a feeling of epic vastness. A great example is Phil Collins’ In The Air Tonight when the drums kick in.
Reverb and echo are not always necessary in film and music, but one should always consider what kind of space you seem to be in when applying these effects. Longer echo or reverb sound like bigger spaces or great halls or canyons, while shorter, tighter echo or reverb could sound like a cramped space, like a small apartment bathroom.
The sound mixer would need to take these very different spaces into consideration when applying echo and/or reverb. Gif courtesy of HBO.
Creating a space with these 2 effects is one way of making different recordings sound unified. It’s often part of any type of mixing in film or music. For instance, if you’re recording music and the drums, amp, and vocals are all recorded at different times with different mics and mic placement, adding a room sound via reverb makes it sound like they may have all been playing at the same time. It is often used during the mastering process to unify final sounds.
When filming a movie, you may record on location, and then in post-production find your project needs Automated Dialogue Replace (ADR). ADR is a re-recording of lines in the studio to replace the dialogue taken on set. By creating space with reverb and echo you can help unify the different mic’ings within a scene such as location sound mixed with ADR. This is especially important if the two types of recordings are near one another.
Justin Joseph Hall is a video director, editor, and post-producer who used to mix audio for film, music, podcasts, and mastered songs for Bootsy Collins and others. For any more info or questions about sound mixing and/or mastering, write to Fourwind Films at info@fourwindfilms.com. Also sign up for our newsletter and podcast, Feature & a short where Brian Trahan, our sound mixer, adds reverb.