Welcome back to the series. In the last article, we talked about the importance of transients when it comes to creating the illusion of near and far in your mix. Today we finish up the last of our principles of depth, reflections.
Reflections, or what we know as reverb, are very important in telling where a sound is in proximity to us. You yourself have probably never heard a sound that didn’t have a little bit of reverb on it, but it’s become so natural to you that you don’t even question it, or sometimes even notice it.
Anytime a sound source is created and we’re around to hear it, it projects sound waves that bounce off the objects surrounding it. Depending on how far away we are and the environment we’re in (whether we’re outside or somewhere indoors), sound travels directly from the source toward walls, surfaces, and structures, and bounces off them, reflecting back in different directions based on the surfaces, obstructions, and the path of the sound wave itself.
These reflections can be thought of in two specific groups: early reflections and late reflections. Early reflections consist of the sound source’s waves bouncing back off nearby objects and coming back to your ears soon after you hear the original sound source itself. Late reflections arrive later because the sound has to take longer paths. It leaves the source, hits nearby surfaces, keeps bouncing deeper into the space, and only then reaches your ears after multiple bounces. That extra travel time is what staggers the direct sound arriving first, then the early reflections and lastly the late reverb tail.
The way we can tell when a sound is closer to us is that normally we hear the direct sound source first, followed by early reflections from nearby bounces of the direct source, then followed by the late reflections. This depends on how big the room is and how many times those reflections that didn’t directly hit our ear initially had to bounce around before finally reaching us.
Take, for instance, someone standing right in front of you in a theater. When they speak, you’ll probably hear their direct voice first. A few milliseconds later, you may then hear the early reflections of their voice bounce off nearby objects and then many milliseconds after that you may hear the late reflections of their voice.
Sometimes you won’t hear much of the late tail at all because the tail depends on how much energy makes it into the room and back to you. A quiet source, heavy damping, blocked paths, and absorbent surfaces can keep the reverb from ever building into something obvious.
But when the tail is audible, the timing still matters. Close sounds arrive first and the room answers a moment later. Farther sounds bring the direct source and the reflections in much tighter succession, which your ear reads as “back in the space.” And in a big room, if you get far enough back, you reach what’s called the critical distance, the point where the direct source and the room are equal. Any further back than that, and you hear less of the direct source and more of the room. Let’s get into some of the ways we can use the tools we have to create this illusion in the mix.
Based on everything we’ve talked about already, it’s obvious that our reverbs are our greatest tools for recreating this realistic sense of reflections in our music. I want to hone in on a few specific controls when we talk about our reverb plugins.
First I want to talk about the relationship between the wet/dry mix control (or the send amount) and the pre-delay knob that you’ll find on your reverb plugin and how those work together to tell the story of depth.
If you look at the depth map, you can see that one of the ways that we can create distance is by using the wet/dry control. We could think of the wet/dry (or, in most cases, when we’re using reverb as a send, the send amount) as the ratio dial for how much of the early and late reflections we are adding to the dry source signal.
You can see as we crank up the wet/dry balance, the wetter that the sound source becomes, the farther we push it back in the mix. Things that are in the near zone, closest to the listener, are mostly dry, and as we work our way back we hit critical distance. The sound source and the wet effect reach a point where we hear close to the same amount of each. This isn’t a perfect science because we’re replicating distance with our tools inside of our DAWs but it’s safe to say that the wetter the direct sound source becomes, the farther it’s perceived in the mix when compared to other sources that are dry. Remember the depth map that you see here is always assuming that you’re comparing two or more signals in the mix. There always needs to be contrast to create near and far.
Now pre-delay is an interesting control that will drastically change the feel of where your sound source is coming from. We can think of the pre-delay as the timing dial. The pre-delay sets the amount of milliseconds between the direct sound source and the reflections. This is another parameter that allows us to create a sense of the source being near or far, much like how we hear reflections in the real world.
If you’re closer to a direct sound source, you may hear the direct signal, then the room reflections later on, as the reflections have to travel further. The farther you are away from the subject, the closer the direct sound will be compared to the reflections, because the direct source is also travelling a further distance. Longer pre-delay times means the dry signal hits your ears first, then the reflections follow later… vs smaller pre-delay times mean the direct signal and the reverb itself to hit your ear around the same time.
Now lastly, take one more look at the depth map and down the center you’ll see early and late reflections. Like we talked about above, the sequencing/order between the direct signal, the early reflections, and the late reflections matters immensely.
Remember:
- Early reflections are the first distinct bounces off nearby surfaces, arriving roughly in the first 50 to 100 ms.
- Late reflections are the dense wash after many different bounces blur together.
Also remember:
- Early reflections tell us, as listeners, what the room size is especially when it comes to width and where the source sits.
- Late reflections help us hear the size of the room and the character of the space altogether.
Some reverbs may come equipped with a control for early and late reflections that you can dial in to help you create a more realistic reverb but many reverbs don’t have these controls readily available. We can work around this by using two different types of reverbs that will help us emulate how we hear these reflections in real life.
A short, small room reverb puts out mostly early reflection-style energy. A small room creates short path lengths of reflections and they arrive fast and densely, with a very short decay and almost no tail. A short room reverb can emulate the early reflections we hear day to day, in normal sized rooms. We can blend it with a longer decay reverb that carries the tail of the late reflections.
Combining these two, we can create the right blend between early and late reflections that can help us create more realistic distance in our music. If you look at the depth map, things in the near zone will have mostly early reflections, and as you move farther back the late reflections take up more and more of the wash.
Back before I learned this concept, I really struggled with learning how to apply spatial processing to my tracks to create a realistic sense of distance. This is truly where the four principles working together used to fall apart for me.
I used to shoot myself in the foot in one of these two ways:
- I would put a reverb on every individual track in the mix, with very, very different settings for pre-delay, early reflections, and wet balance. All of those reverbs blending together never really told the listener that they were in a dedicated space. It made my mixes feel washed out and, worst of all, flat, especially after I got the volume, the EQ, and the transients right beforehand.
- Once I learned about sends, I would use the same reverb on all of my tracks, with the same settings for pre-delay and decay times. The only thing changing was the wet amount. That ratio dial was doing some of the work, the wetter tracks did sit farther back, but the timing dial never moved. With the pre-delays and the early and late reflections the same on everything, it never gave off a realistic sense of distance, just more wet or less wet inside of the same room.
What really clicked for me was understanding that different distances needed different settings, and to get that effect I needed multiple sends, each one set up for its own distance. Once I got those settings right, the placement actually became about the send amount and things stopped fighting for space in the mix.
I took it even further by creating three pairs of reverb sends: a short and a long reverb for the near, the mid, and the far zones themselves. Each pair had its own settings for pre-delay times and the blend between early and late reflections, which allowed me to get way better results than adding a single reverb on everything. But you don’t need six reverbs to get there. Two rooms will carry most of the weight, and that’s what we’ll build next.
The Move
- Build Your ER/LR Reflections
Start by building two sends with the same reverb but differing dialed-in settings. Name one “Early Reflections” and name the other “Late Reflections.” The Early Reflections send should have a longer pre-delay time, anywhere from 30 to 50 ms as a starting point, with a shorter decay. The one named Late Reflections should have little to no pre-delay, with a longer all-around decay time. If you want settings that sit with your track’s tempo, you can use a time delay calculator like the one here (https://anotherproducer.com/online-tools-for-musicians/delay-reverb-time-calculator/), where you can go in, enter your BPM, and get great starting points to build your long reverb and your short reverb.
2. Place sounds in the near/far zone with send amounts.
Use the send amounts on your early reflections and late reflections to place your sounds in the near or far zone in your mix. For front sounds, use only a little bit of send, the majority being early reflections. As sounds go further back in the room, add more send amount and incorporate more of the late reflections reverb.
3. Mix Check
Once you do this across all the elements in the mix, now it’s time to check the whole picture. Bypass both sends to make sure that you are contributing to depth and that, if done right, all four of the principles are working together to create the bigger picture. When bypassing the sends the mix should feel like it flattens and then, when reactivated, it feels like it just opens up.
That’s going to wrap up this series on the four principles of depth:
Volume: our first lever that sets the initial distance.
Frequency: which clues us in to how close something is to us, based off of the brightness and the intimacy of the low mids.
Transients: our third lever, which helps us replicate proximity with the initial snap of a sound, and the fall-off of the transient as it gets further back in the room.
Reflections: the bounces of the initial sound source that subconsciously help tell us where a sound is placed in a space, helping us complete the illusion of depth.
Remember that all of these have to work together to create the bigger picture. Use the depth map above to make sure that your decisions are in line with each other. This is how we can create that pop-out book-like effect rather than having our mixes feel flat and pressed up against the glass.
To close out this series, I’d like you to continue with your session from the last three weeks and build the two sends. Try applying this to the previous decisions you’ve already made, using the other levers to create depth.
You can also download the 4 Dimensions of Depth Cheat Sheet here (free PDF)
Enjoy!
