Compress audio in 4 steps:
- Select the audio you want to compress
- Go to Effect → Volume and Compression → Compressor
- Choose a factory preset (for example, Voice Memos Balance)
- Click Apply or use it as a real-time effect
What Is Audio Compression?
Audio compression automatically reduces loud peaks in your signal and can then raise the overall perceived volume. The result is a more consistent track where quiet phrases are easier to hear and sudden loud moments are less jarring. This is why compression is one of the core tools for podcasts, vocals, voiceovers, and mastering.
What does a compressor do?
A compressor turns down the volume only when the audio gets too loud, then optionally boosts the final level. You keep detail and intelligibility while smoothing out uneven dynamics.
How to Use the Compressor in Audacity
Step 1: Select Your Audio
Open your file in Audacity and select the region you want to process. To compress the entire track, click the track panel or press Ctrl A ⌘A .
Step 2: Open the Compressor
Navigate to Effect > Volume and Compression > Compressor to open the effect window. If you use real-time effects, you can also insert it in the track or master effect chain.
Step 3: Choose a Preset or Adjust Settings
Start with a factory preset and fine-tune as needed. Typical voice compression begins with a moderate ratio and threshold that only engages on louder words.
Step 4: Preview and Apply
Use Preview to compare behavior before committing. Then click Apply. If your result feels over-compressed, reduce ratio or raise threshold and try again.
Compressor Settings Explained
Threshold
The level where compression begins. Signals above threshold are reduced; signals below are untouched. Lower thresholds apply compression more often.
Ratio
Controls how strongly peaks are reduced after crossing threshold. A 4:1 ratio is moderate, 8:1 is more aggressive, and 2:1 is subtle.
Make-up Gain
Raises output level after peaks are controlled. This helps restore loudness and improves clarity of softer phrases.
Knee Width
Determines whether compression starts abruptly (hard knee) or gradually (soft knee). A soft knee often sounds more natural on voice and acoustic material.
Attack (Lookahead)
Attack sets how quickly compression reacts to incoming peaks. Faster attack catches transients earlier; slower attack preserves initial punch.
Release
Release controls how quickly compression stops after the signal falls back below threshold. Too fast can pump; too slow can sound flattened.
| Setting | What it does | Typical value |
|---|---|---|
| Threshold | Level where compression starts | -20 to -10 dB |
| Ratio | Amount of gain reduction above threshold | 2:1 to 8:1 |
| Make-up Gain | Output boost after compression | +3 to +10 dB |
| Knee Width | Soft/hard transition around threshold | Around 6 dB (soft) |
| Attack | How fast compression engages | 10–50 ms |
| Release | How fast compression recovers | 100–300 ms |
Factory Presets
Built-in presets (Presets & Settings):
- Voice Memos Balance – Smooths phone recordings with uneven levels
- Voice-focused presets – Useful for podcasts, narration, and dialogue
- Beefy Master – Adds density to full mixes
- Deep Dive Master – Subtle control with minimal tonal shift
- Great Impact – Emphasizes punch and impact
- Climax Impulse – Brighter attack for transient-heavy sounds
When to Use Compression
- Podcasts: Keep speech levels consistent between speakers.
- Vocals: Prevent words from disappearing or jumping out too loudly.
- Mastering: Add controlled loudness and cohesion to a final mix.
- Audiobooks: Improve listening comfort over long sessions.
- Video dialogue: Balance spoken voice against effects and music.
- Live recordings: Tame unpredictable spikes.
Tips for Best Results
- Start conservatively and compare processed vs original often.
- Aim for roughly 3–6 dB gain reduction on loud peaks as a safe starting range.
- If the sound feels "squashed," reduce ratio or raise threshold.
- Use make-up gain carefully to avoid clipping at output.
- Consider normalizing after compression if you need final loudness matching.
Frequently Asked Questions
What ratio should I use for vocals?
A 3:1 to 4:1 ratio
is a practical starting point for natural voice control.
Why does my audio sound quieter after compression?
Compression lowers peaks. Add make-up gain or normalize afterward.
Should I compress before or after EQ?
Most workflows
use EQ first, then compression, but either can work depending on the source.
What is attack vs release?
Attack is how fast
compression starts; release is how fast it recovers after peaks.
Can compression make audio sound bad?
Yes,
over-compression can sound lifeless. Use moderate settings and A/B compare.
What threshold should I set?
Set threshold so
compression engages mostly on louder moments.
Is Audacity's compressor suitable for pro work?
Yes,
Audacity's modern compressor is capable for production voice and music
workflows.
How do I compress multiple tracks at once?
Use a
master effects workflow to process the mixed output in one pass.
Download Audacity Free
Ready to even out your levels and improve clarity? Download Audacity for free on Windows, macOS, and Linux.