Compressor Cheat Sheet

Compressor Type	What It Does	Use It For	How to Use It	Recommended Plugins	Pro Tips
VCA	Uses a voltage-controlled amplifier for fast, transparent compression with minimal coloration. Ideal for maintaining clarity while controlling dynamics.	Vocals (lead/singing), bass guitar, drums (overheads), mix bus.	Fully adjustable ratio, attack, and release. Set medium ratio (4:1-8:1) and adjust threshold to catch peaks. For vocals, use on lead singers to even out phrasing. For bass guitar, control low-end thump. On mix bus, apply lightly for glue. Start with soft knee.	SSL G-Master Buss Compressor Waves CLA-2A API 2500	Great for glueing mixes. Start with slower attack for vocals to preserve transients.
FET	Employs field-effect transistors for aggressive, fast attack compression that adds punch and character.	Drums (kick/snare), percussion, electric guitar, bass (for punch).	Ratio often in fixed steps (e.g., 4:1, 8:1, 12:1, 20:1 via buttons), attack/release via switches (fast/slow). Dial in high ratio with fast attack for immediate control. For drums, compress snare for snap or full kit for cohesion. On electric guitar, tame peaks and add sustain. For bass, enhance punch. Experiment with "all buttons in" mode.	Universal Audio 1176 Waves CLA-76 Empirical Labs Distressor	Use "all buttons in" for maximum aggression on drums. Watch for over-compression artifacts.
Optical	Uses a light-dependent resistor for smooth, musical compression that responds naturally to dynamics.	Vocals (background harmonies), acoustic guitar, piano, strings, mix bus.	Ratio is fixed (around 4:1-6:1), attack/release adjusted via gain and peak reduction knobs. Use gentle settings with slower attack for smooth response. For vocals, apply to background harmonies to blend them. On acoustic guitar or piano, even out dynamics. For mix bus, employ for subtle evening. Adjust release for natural decay.	Teletronix LA-2A Waves CLA-2A Universal Audio LA-2A	Excellent for evening out vocals without squashing. Use slower release for smoother results.
PWM	Uses pulse-width modulation for precise digital control, offering clean and responsive compression with low latency.	Modern digital mixes, vocals, instruments needing surgical precision, EDM elements.	Fully adjustable ratio, attack, and release. Fine-tune for clean sound. For vocals in digital productions, control sibilance precisely. On EDM synths, apply for tight transients. For mix bus, use as transparent limiter. Adjust PWM parameters for warmth.	Waves SSL G-Master (digital mode) FabFilter Pro-C 2 iZotope Neutron	Ideal for transparent limiting in digital workflows. Adjust PWM depth for subtle saturation.
Vari-Mu	Variable gain reduction using tubes, providing smooth and musical compression with vintage character.	Vocals (classical/opera), strings, orchestral sections, full mix.	Ratio often fixed or limited (2:1-6:1), attack/release adjustable. Opt for moderate settings with slower attack for musical feel. For classical vocals, enhance presence. On strings/orchestral, apply for blend. For full mix, use in mastering for warmth. Let tube character shine.	Manley Vari-Mu Chandler Limited Zener Limiter Waves Manny Marroquin Tone Shaper	Perfect for complex, dynamic sources. Use for mastering to add cohesion without harshness.
Diode	Utilizes diode bridge circuitry for fast, aggressive compression with a distinct "pumping" character.	Drums (full kit), bass, electric guitar, percussion-heavy tracks.	Ratio adjustable (4:1-20:1), attack/release via controls or modes. Crank ratio with fast attack for punch. For full drum kits, add energy and tightness. On bass/guitar, apply for aggressive control. For percussion, enhance rhythm. Embrace pumping effect.	DBX 160 Waves dbx 160 Empirical Labs Distressor (diode mode)	Great for adding punch to drums. Use for creative pumping effects in rock or EDM.
Multi-band	Compresses different frequency bands independently, allowing targeted dynamic control.	Full mix, mastering, problematic low-mids/highs, vocals with sibilance issues.	Ratio, attack, release adjustable per band. Adjust per band for surgical control. For vocals with sibilance, compress highs to tame "ess" sounds. On mixes, target muddy lows or harsh highs. In mastering, balance frequency dynamics. Set crossovers strategically.	Waves C6 Multiband Compressor FabFilter Pro-MB iZotope Ozone Imager	Set crossovers to isolate problem areas. Use for de-essing vocals or taming muddy lows.
Upward	Expands or compresses upward, boosting quieter parts to even out dynamics (reverse of traditional compression).	Vocals with inconsistent levels, acoustic instruments, room mics, subtle enhancement.	Ratio adjustable for expansion (1:1.5-1:4), attack/release controls. Use expansion to lift quiet parts. For inconsistent vocals, bring up soft phrases. On acoustics/room mics, enhance ambiance. Blend with dry signal. Avoid over-use.	Waves Renaissance Compressor (upward mode) FabFilter Pro-C 2 (with negative ratio) Any expander plugin	Use sparingly to avoid unnatural pumping. Great for bringing up quiet details in mixes.
OTT	Aggressive, multi-band compression with built-in distortion for over-the-top character and loudness.	Drums, bass, electric guitar, full mixes needing extreme punch and saturation.	Ratio fixed or high (10:1-∞:1), attack/release adjustable, drive control. Push with drive for saturation. For drums/bass, add massive low-end. On guitar, for distorted sustain. For mixes, as creative bus compressor. Blend wet/dry.	Xfer Records OTT Waves CLA-2A (pushed hard) Slate Digital Virtual Mix Rack	Designed for loud, saturated sounds. Blend wet/dry to control intensity.
Limiter	Brickwall limiting to prevent peaks from exceeding a threshold, ensuring maximum loudness without clipping.	Mastering, mix bus, vocals/instruments needing peak control.	Ratio fixed at ∞:1, attack/release adjustable. Set fast attack for brickwall. For mastering, final stage for loudness. On mix bus, prevent clipping. For vocals/instruments, surgical on peaks. Monitor distortion.	iZotope Ozone Maximizer Waves L2 Ultramaximizer FabFilter Pro-L 2	Use as the last stage before dithering. Monitor for distortion at low thresholds.
Parallel	Blends compressed and uncompressed signals for added punch without squashing dynamics.	Drums, bass, vocals, full mix (technique using any compressor).	Depends on compressor used (adjustable or fixed). Compress duplicate track heavily, blend back. For drums, parallel overheads for snap. On bass/vocals, enhance presence. For mix, apply to bus for glue. Adjust blend ratio.	Any compressor (e.g., Waves SSL G-Master) Use sends/returns in DAW FabFilter Pro-C 2	Compress heavily on the parallel channel. Adjust blend for natural enhancement.
Negative	Uses negative ratio where louder signals are boosted, creating expansion or creative distortion effects.	Creative sound design, drums (for emphasis), experimental processing.	Ratio adjustable to negative (-2:1 to -10:1), attack/release controls. Apply for reverse dynamics. For drums, emphasize transients. In sound design, for effects. Blend subtly. Use fast attack for distortion.	Waves Renaissance Compressor (negative mode) FabFilter Pro-C 2 Custom settings in digital compressors	Use subtly for emphasis or heavily for distortion. Can create "reverse" dynamics.