What Is Attack?
Attack is the time it takes for the compressor to begin reducing gain after the signal crosses the threshold. A fast attack reacts almost immediately, catching sharp peaks before they pass through. A slower attack lets the first edge of the sound through before compression takes over.
This matters because the first moment of a sound often carries clarity and impact. On drums, that first hit is the transient. On voice, it can be a consonant, a sudden laugh, or a hard word. If attack is too fast, a source can lose punch and feel smaller. If attack is too slow, peaks may slip through and still sound uncontrolled.
What Is Release?
Release is the time it takes for the compressor to stop reducing gain after the signal falls back below the threshold. A short release recovers quickly, which can keep speech lively but may create audible level movement. A long release recovers slowly, which can sound smooth but may keep the audio suppressed into the next word or beat.
Too fast release can cause pumping, where background sound rises and falls after every loud moment. Too slow release can make audio feel flattened because the compressor never fully resets before the next phrase. Release is usually tuned by listening to the rhythm of the source, not by copying a fixed number.
Fast vs Slow Attack
Attack speed changes the front edge of the sound. If the source has sharp peaks that hurt the listener or overload the next processor, use a faster attack. If the source needs punch, pick detail, or natural speech articulation, use a slower attack and control peaks with threshold and ratio first.
| Attack speed | Sound character | Common use |
|---|
| Fast attack, 0.1-5 ms | Tight, controlled, less transient punch | Sharp vocal peaks, aggressive control, safety before limiting |
| Medium attack, 5-20 ms | Balanced and practical | Podcast voice, streaming mic, many vocals |
| Slow attack, 20-50 ms or more | Punchier, more open, more transient detail | Drums, acoustic guitar, expressive vocals, mix bus |
Fast vs Slow Release
Release speed changes how the compressor breathes with the performance. The best release often returns close to zero gain reduction between phrases or beats without making the level wobble. If the gain reduction meter snaps back constantly, listen for pumping. If it barely returns, listen for dullness.
| Release speed | Sound character | Common use |
|---|
| Fast release, 20-80 ms | Energetic, can be lively or pumpy | Quick speech, drums, sources with short peaks |
| Medium release, 80-200 ms | Natural recovery for many sources | Podcast, voice-over, streaming microphone, vocals |
| Slow release, 200 ms and above | Smooth but potentially flattened | Bass, music bus, slower material, gentle leveling |
Starter Attack and Release Settings
Use these ranges as a first pass, then adjust against the actual recording. Timing interacts with threshold and ratio, so a setting that works at 2:1 may feel too heavy at 6:1.
| Source | Attack | Release | Goal |
|---|
| Podcast voice | 10-20 ms | 80-150 ms | Stable words without dull consonants |
| Vocal | 5-30 ms | 80-200 ms | Control peaks while keeping expression |
| Drums | 10-30 ms for punch, faster for peak control | 50-150 ms | Shape impact and room energy |
| Bass | 15-40 ms | 120-300 ms | Even notes without distortion or wobble |
| Streaming mic | 5-15 ms | 70-140 ms | Catch sudden loud moments while staying conversational |
| Background music | 20-50 ms | 150-300 ms | Gentle leveling under speech |
How Attack and Release Cause Pumping
Pumping happens when compression changes level in a way the listener notices as movement rather than natural dynamics. A loud word may pull down the room tone, then the release brings it back up between words. In music, a kick drum may duck the entire track so the mix swells after each hit.
To reduce pumping, first check whether the compressor is working too hard. A lower ratio, higher threshold, or less makeup gain may solve the problem before timing changes. If release is snapping back too quickly, slow it down. If the compressor stays down too long, shorten release or raise threshold so it has room to recover.
- Reduce ratio if the gain reduction feels too obvious.
- Raise threshold if compression is active all the time.
- Slow release when level movement is chattering between words or beats.
- Adjust makeup gain so quieter noise is not exaggerated after compression.
Attack and Release vs File Compression
Attack and release affect timing and feel. They do not directly decide file size. You can tune a voice beautifully with compressor timing and still export a very large file if you choose WAV, high sample rate, or a high bitrate.
For smaller downloads or uploads, use browser-based file compression after editing your sound. The Audio Compressor can reduce MB using bitrate, format, and target size, while the Audio Compressor vs Limiter page explains where timing overlaps with peak safety.
Attack and release affect timing and feel. For smaller downloads or uploads, use browser-based file compression after editing your sound.