How to Create Realistic Reverb for your Films

Whenever we’re working on a sound mix for a short project or film, we always run into the same time-consuming issues: dealing with reverb sentences for too long, trying to embed and match the natural ambiance of the scene to the Foley, sound effects and additional ADR.

If you’re a filmmaker working on your first project or on a short film, then chances are you’re also responsible for the sound part. If so, then this hack is for your. What if we told you that there’s a way to capture the genuine reverb of a room on set or on location with your standard sound kit in less than a minute? Not to mention, it will also be completely controllable in your digital audio workstation. Sounds good, right? Check it out and step your sound and filmmaking game up a notch and become a better sound professional.

In order for you to achieve this then you have got to understand why you need to add reverb to post-production sound. Surely, you’ve come across clips that only use sound and audio packs purchased online, but the overall sound feels totally dry, meaning it has no effects added. Of course, there are plenty of ways to enhance and improve this kind of clips or projects, and one of those ways is by adding reverb to some of the elements contained therein. 

Reverb allows you to provide the audience with the impression that whatever action is happening is actually happening inside the room where it takes place. Think of footsteps, for example: if the action shows someone walking across the room, you’ll probably want to add some reverb to the footsteps to give the impression that the action is indeed happening inside that room, and that they belong to the scene.

Working with reverb in hopes of matching the audio to the Foley and the other sound elements is, as mentioned above, rather time-consuming. So, how to make this more efficient? Next time you’re doing room tone, run up to where the actors are, or wherever the microphones are pointed, and clap 2 or 3 times. At the end of every clap, make sure that the echo and the reverb in the room are fully subsided before clapping again. Try to use a deep clap, not a bright clap. 

What you’re essentially doing is creating an impulse response recording that is essentially giving you the nature of the room in which the action takes place. You will now be able to use this in post-production, finding it easier to balance your natural or on the set sound with the rest of your sound elements.

If you want to put this into practice, go find a room with a sheer array of unusable reverb, like a stairwell at the back of a building or something similar, and record a dialogue clip. Now, you’ll notice that given the amount of reverb, that audio needs replacing. Then, record the claps as suggested above and re-record the dialogue in a low noise, low reverb environment, such as your studio, mimicking the original as close as possible.

With a clean dialogue replacement and the impulses created through the claps on set, you can now send that file to your audio guy (or work with them yourself). In your digital audio workstation, you will be working with three different tracks: the original on set audio, the ADR audio, and the claps.

The first thing you’ll probably want to do is add a little bit of contouring with your EQ to the ADR, because, even you if use the same microphone in ADR as you did on the set (which you should), there’s going to be a tiny difference between both tracks, so you should strive to balance both with the EQ. Remember, this is all about subtlety. You will do this to help you get closer to what you want to achieve, so try not to overdo it.

Open your clap files (impulses) in your spectral editor and take a look at the waveform view. What you should do from this point is to create individual files out of each clap. Zoom in on the attack of the first clap as closely as you can so that you don’t have any space before the clap. Then, take the zoom selection tool and go almost all the way to the next clap, right before it. You should now have selected an entire clap, also selecting all the echo and reverb that is present. Select a marker and repeat the process for the rest of the claps.

Once you’ve saved all the claps as individual files, go to the ADR version of your dialogue and instantiate the convolution reverb from your audio software. Load one of the impulses, and what the software will do is alter the file based on the parameters that you’re using (the ones obtained from the claps). The difference now is that you will be able to control the settings. Play a bit with them until the result is what you’re looking for. Happy recording!

*The images used on this post are taken from Pexels.com