Applying Reverb and Delay to Your Tracks | Home Recording Basics

Last week’s installment of our Home Recording Basics series tackled one of the most misunderstood elements of audio: compression. We broke down some common misconceptions that surround dynamics processing and detailed the when and why of applying compression to your tracks.

But if you’ve gotten this far and still feel like something is missing, you’re probably ready to add some time-based effects to your song. These effects are what make a track feel like it's larger than life.

Effects like reverb and delay alter the timing of a signal to help create a sense of space. They can make a track sound bigger, wider, or deeper. They can be used to subtly push an instrument back in the mix or simply to add excitement.

Most importantly, they can be used to convince the listener that something was recorded in a space that it wasn't. The simplest way to do that is to record a dry signal (one that doesn't capture much room tone) and use the appropriate reverb type to create the atmosphere you want.

Types of Reverb

Reverb units simulate what a signal would sound like if it were played in a particular space instead of your bedroom. You can simulate any number of spaces, from a small tile room bathroom to a beautiful marble church with 40 foot ceilings to an imaginary space, like an underground cave on the moon.

Most commonly, reverbs are broken down into one of the following types:

Room reverbs are just that—rooms. They can simulate small tile rooms, large wooden rooms, and anything in between. They tend to capture the less-than-perfect acoustics of those spaces, and that's part of their charm. Rooms come in all shapes and sizes and can be made using an assortment of materials.

Hall reverbs are designed to simulate concert halls. These are well-treated spaces with high ceilings designed with acoustics in mind, so there tend to be minimal "imperfections" like frequency buildups and negative reflections. They tend to sound lush, with long reverb times.

Plates are an old-school form of reverb. Engineers would literally send a signal to a large metal plate housed in a wooden box and record its sound vibrating through the plate and bouncing around the box. They tend to sound bright and somewhat metallic, with medium-to-long reverb times. They’re most commonly used on vocals and occasional snare drums if you're not going for the "kit in a room" sound.

Chamber reverbs are kind of a cross between a hall and a plate. A chamber is usually a large, rectangular enclosure made of highly reflective material, like metal or concrete. This causes long reverb times as with a hall, but colorful frequency bumps like a plate.

Spring reverbs are similar to plate reverbs, but instead of a plate creating the reverberation, it's a small spring. Spring reverbs tend to sound a little thinner, with shorter reverb times. They're most commonly used on guitars and vocals, especially when you're looking for that classic "slapback" sound.

Digital reverbs afford us the opportunity to create a space instead of simulating one. Ambience or ambient reverbs are environments designed to add atmospheric ambiance, but that doesn't mean they're a room. What about a football field? Or the deck of a yacht? Or the Grand Canyon? They all add their own unique ambiance.

Nonlinear reverbs use crazy algorithms to produce sounds that wouldn't be possible to achieve in real life but may be perfect for your sound design needs. Examples include reverbs that get louder over time instead of quieter, gated or processed reverbs, and even reverbs with random swells and pitch shifts.

Reverb Parameters

Aside from the actual reverb type, most units have several parameters for controlling the overall tone of the reverberations.

Room Size / Decay Time: The first control is usually decay time, which controls the length of the reverberation. Some units use "room size" instead, which controls the decay time by adjusting the size of the room itself. Other units offer both controls for fine-tuning your sound.

Early Reflections: The sounds of the instrument bouncing off of the walls are called the early reflections. Increase the level of the early reflections to move the listener closer to the walls, and decrease it to put them toward the center of the room.

Pre-Delay: Pre-delay is a measurement of how far the listener is from the sound source. Small rooms have shorter pre-delays, and larger rooms have longer pre-delays.

Damping: People are generally pretty squishy, and squishy things absorb sound. Damping controls the amount of acoustic absorption in a space. Want to to sounds like your alone in a giant church? 0% Damping. Want to sound like you're in a concert hall with arched ceilings and padded seats? Crank it up.

Types of Delay

You're probably already familiar with delay. You know that old bit where someone shouts something in a big cave and ends up arguing with their own echo? Yeah, that's delay.

Delay units literally delay an audio signal to create an echo effect. Depending on the timing of the delay, you can achieve various results. Oftentimes, delays are used to add width and depth to tracks within their given acoustical space.

A delay isn't considered a true echo until the repetition can be clearly distinguished from the original. If the delay time is any shorter than that, it falls into one of three categories.

A delay isn't considered a true echo until the repetition can be clearly distinguished from the original."

The first delay type isn't actually a delay at all. Phasers are delay units with minimal delay time (0-5ms). They simply copy a signal and shift the phase of the duplicate to create sweeping frequency notches that create a subtle rippling effect.

Flangers use a delay time of 5-20ms, which is modulated at a constant rate to create a more dramatic effect with richer harmonics and saturation. Phasers are often used to make mono tracks into stereo.

By duplicating the signal, delaying it by 20-40ms, and adding in some subtle pitch variations, you can create a chorus effect, which gives the illusion of doubling the signal. Commonly used on background vocals and keyboards.

Echoes use a delay time so long that the delayed signal becomes easily distinguishable from the original, which varies from track to track. In most cases, echoes are synced to the tempo of the song in 1/8, 1/4, or 1/2 note intervals.

Delay Parameters

Aside from the actual delay time—which is used to set the length of the delay in milliseconds—several other parameters are used to control the subtleties of how the duplicated signal interacts with the original signal.

Feedback: There's a big difference in a signal that repeats once and a signal that keeps on repeating forever. Use the feedback knob to control how many repetitions of the delay you hear. The lower the feedback amount, the fewer repetitions. Just be careful: increasing the feedback too much will actually create a feedback loop.

Rate: In most cases, delay units modulate the duplicated signal in some way. The rate knob controls how quickly the copied signal oscillates.

Depth: Similar to rate, the depth knob controls how aggressively the duplicated signal is modulated. Turn up the rate and the depth for more exaggerated effects.

Putting It All Together

Though you and your song have come a long way, the journey is far from over. Mixing is a reactive art form, and being able to identify problems in a mix and know how to correct them takes time, patience, and practice—just like learning an instrument.

Learn more about how to record music at home on our Basics of Home Recording homepage.