Effects Basics: Reverb, Delay, and Compression

GarageBand includes a full library of built-in effects. Most projects only really need three of them to make a huge difference: reverb, delay, and compression.

Adding an effect to a track

Open a track's Smart Controls and look for its effects/plugin section, or add one directly from the channel strip. Effects stack in a chain, processing the signal in order from top to bottom — where an effect sits in that chain can change how it sounds, especially with compression.

Reverb: simulating space

Reverb recreates the natural reflections of a physical space — a small room, a hall, a plate reverb's metallic shimmer. Every dry recording sounds slightly unnatural because it was captured close to a microphone with none of a real room's ambience; a touch of reverb is often what makes a vocal or instrument feel like it belongs in the same space as everything else.

Start subtle. It's much easier to add more reverb than to fix a recording that's drowning in it.

Delay: rhythmic echoes

Delay repeats the input signal after a set amount of time, like a rhythmic echo. Short delays add thickness and width; longer, tempo-synced delays create audible rhythmic repeats — useful on a lead vocal ad-lib, a guitar line, or anywhere you want extra rhythmic interest without recording another take.

Most delay effects can sync to your project's tempo, so the repeats land in time with the beat automatically.

Compression: controlling dynamics

Compression reduces the difference between a sound's loudest and quietest moments, making a performance feel more even and controlled. It's especially useful on vocals and bass, where natural dynamic range can otherwise make a part disappear in quiet moments and jump out in loud ones.

Key controls to know:

• Threshold — the level above which compression starts working.
• Ratio — how strongly the sound gets pulled down once it's above threshold.
• Attack / Release — how quickly compression kicks in and lets go.

If compression makes something sound squashed or lifeless, you've likely gone too far — back off the ratio or raise the threshold.

A sensible default chain

For a lead vocal, a common (not mandatory) starting order is: light compression first to even things out, then reverb and/or delay after, so they're working on an already-controlled signal rather than one full of wild volume jumps.

What's next

Effects shape how tracks sound in isolation. The next lesson covers automation — changing effect and volume settings over time, so a mix actually moves and breathes instead of sitting static for the whole song.