FabFilter Pro-C 3 vs Sonible smart:comp 3: Compression Plugin Comparison
The compressor plugin market offers an abundance of choices, but two options consistently appear in professional discussions: FabFilter Pro-C 3 and Sonible smart:comp 3. Both represent their respective companies’ approaches to dynamic processing, yet they target the compression task from fundamentally different angles.
Pro-C 3 extends FabFilter’s tradition of precise, hands-on control with extensive metering and multiple compression algorithms, while smart:comp 3 employs Sonible’s AI-assisted learning technology to analyze source material and suggest appropriate settings through its Compression Matrix system.
This comparison examines the technical specifications, workflow approaches, and practical applications of both plugins to help you determine which tool aligns with your production requirements.
Overview and Philosophy
FabFilter Pro-C 3
Pro-C 3 operates as a traditional compressor with modern enhancements. The plugin provides 14 distinct compression styles organized into three categories:
| Category | Styles |
|---|---|
| Modern | Clean, Versatile, Smooth, Punch, Upward, TTM |
| Classic | Op-El, Vari-Mu, Classic, Opto |
| Utility | Vocal, Mastering, Bus, Pumping |
Each style implements different detection algorithms, topologies, and smoothing curves that affect how the compressor responds to incoming audio. The interface presents all parameters visually through a large animated level display, optional knee display, and comprehensive metering.
Sonible smart:comp 3
Smart:comp 3 takes a different approach by incorporating machine learning into the compression workflow:
- Select a source profile
- Initiate the learning process
- The plugin analyzes audio and generates a Compression Matrix
- Navigate the matrix to find optimal settings
Rather than adjusting individual parameters from scratch, users navigate a learned space that maps compression characteristics along two axes: snappy-to-punchy and dynamic-to-dense.
Key Distinction: Pro-C 3 assumes familiarity with compression concepts and provides tools for precise implementation. Smart:comp 3 bridges the knowledge gap by translating technical parameters into semantic dimensions.
Compression Algorithms and Styles
FabFilter Pro-C 3 Styles
Pro-C 3 offers 14 compression styles, with six new additions in version 3:
Modern Category
| Style | Description |
|---|---|
| Clean | All-around low-distortion feedforward style with program-dependent behavior |
| Versatile (new) | Adapts response based on attack time—punchy at longer times, tight at shorter times |
| Smooth (new) | Maintains gentle compression regardless of settings; ideal for bus glue |
| Punch | Traditional analog-like compression that works across various sources |
| Upward (new) | Pumping upward compression that increases level below threshold |
| TTM (new) | “To The Max” multiband combining upward and downward compression |
Classic Category
| Style | Description |
|---|---|
| Op-El (new) | Opto-like tube compression with smooth warmth |
| Vari-Mu (new) | Variable-mu topology offering colorful feedback compression |
| Classic | Vintage feedback, program-dependent style |
| Opto | Slow, soft-knee, linear optical compression |
Utility Category
| Style | Description |
|---|---|
| Vocal | Automatic knee and ratio for bringing vocals forward |
| Mastering | Maximum transparency with minimal harmonic distortion |
| Bus | Pleasant glue for drums, mixes, or tracks |
| Pumping | Deep pumping effects for drums or EDM |
Sonible smart:comp 3 Styles
Smart:comp 3 provides four compression engines that define overall character:
| Style | Timing | Saturation | Use Case |
|---|---|---|---|
| Clean | Fast, transparent | None | Sources requiring clarity |
| Smooth | Gentle envelope | Soft | Vocals, pads, melodic content |
| Aggressive | Fast, strong transient control | Pronounced | Drums, percussion, bass |
| Custom | Fully adjustable | Fully adjustable | Personalized compression design |
Each style defines both attack/release shapes and saturation characteristics. The Attack & Release Shaper display visualizes these timing curves.
Character and Saturation
Pro-C 3 Character Modes
Pro-C 3 introduces Character modes that add analog saturation, coloring, and drift:
| Mode | Character |
|---|---|
| Tube | Warm harmonic coloring |
| Diode | Different harmonic profile |
| Bright | Enhanced high-frequency harmonics |
Additional Controls:
- Drive — Controls saturation intensity
- Routing — Pre (before compression) or Post (after compression)
💡 Tip: Post routing saturates transients remaining after compression. Pre routing saturates peaks before compression affects them—wholly different characters.
smart:comp 3 Saturation
Smart:comp 3 integrates saturation into its Style system:
- The Custom style provides dedicated
SaturationandCharacterparameters - A saturation curve visualization shows input-to-harmonic generation relationship
- Each preset style has its own inherent saturation behavior
Sidechain Processing
FabFilter Pro-C 3 Sidechain
Pro-C 3 offers extensive sidechain capabilities:
Trigger Sources
| Source | Description |
|---|---|
| Internal | Main input audio |
| External | External sidechain input |
| Host Sync (new) | Pulse synced to host tempo with offset and length controls |
| MIDI | Triggered by MIDI note-on messages |
Sidechain EQ
- Up to 6 freely positionable bands
- All filter shapes from Pro-Q including all-pass and brickwall
- Slopes up to 96 dB/octave
- Bands can be set to mid-only or side-only
Stereo Linking Modes
| Mode | Behavior |
|---|---|
| Mid | Trigger on and compress mid signal only |
| Side | Trigger on and compress side signal only |
| M>S | Trigger on mid, compress side only |
| S>M | Trigger on side, compress mid only |
The Stereo Link knob ranges from 0% (independent channels) through 100% (linked) to mid-only or side-only processing.
Sonible smart:comp 3 Sidechain
Smart:comp 3 provides internal and external sidechain options with a unique feature:
Spectral Ducking: When using external sidechain, the plugin analyzes the sidechain source’s spectral content and applies gain reduction only in frequency regions where both signals compete—far more transparent than broadband ducking.
Sidechain EQ Features:
- Parametric and shelving filter options
- Individual band enable/disable
- Gain and frequency adjustment via click-and-drag
- Q factor via scrolling
- Sidechain solo monitoring
Spectral Processing
This represents a significant distinction between the plugins.
smart:comp 3 Spectral Compression
Smart:comp 3 includes dedicated frequency-dependent compression on top of broadband processing:
| Parameter | Function |
|---|---|
| Amount | Strength of spectral processing (higher = more frequency-dependent) |
| Frequency Borders | Range where spectral processing operates |
| Color | Tonal tilt—Bright compresses lows more; Dark compresses highs more |
⚠️ Note: Pro-C 3 does not include built-in spectral or multiband compression. However, the detailed sidechain EQ allows shaping what frequencies trigger compression, and multiple instances can achieve multiband approaches.
Visual Feedback and Metering
FabFilter Pro-C 3 Displays
| Display | Function |
|---|---|
| Level Display | Animated view showing input (dark grey), output (light grey), and gain reduction (red line) |
| Knee Display | Input/output relationship visualizing Threshold, Ratio, Knee, and Range |
| Peak Meters | Accurate peak levels with EBU R128 / ITU-R 1770 loudness |
| Compact Layout | Hides displays, shows horizontal meters only |
Meter Scale Options: 9 dB (mastering precision) to 90 dB (general mixing)
Sonible smart:comp 3 Displays
| Display | Function |
|---|---|
| Compression Matrix | Visual representation of learned compression space |
| Compression Scope | Highlighted area showing valid configuration range |
| Signal History | Input signal and gain reduction over time |
| Input/Output Meters | Real-time level monitoring with adjustable scale |
💡 Scope Size Meaning: Large scope = material allows broad dynamic shaping. Small scope = limited flexibility (e.g., already-compressed material).
Workflow Approaches
Traditional Control — Pro-C 3
Set Threshold → Adjust Ratio → Dial Attack/Release → Fine-tune Knee/Range → Apply Make-up GainAutomation Features:
- Auto Threshold (new) — Level-independent threshold; useful for dialog with varying levels
- Auto Release — Adjusts release based on gain reduction
- Auto Gain — Maintains consistent loudness while adjusting parameters
AI-Assisted Learning — smart:comp 3
Select Profile → Start Learning → Navigate Compression Matrix → Refine with Traditional ControlsCompression Matrix Dimensions:
| Dimension | Character |
|---|---|
| Snappy | Fast, tight, transient-focused |
| Punchy | Weight, body, impact emphasis |
| Dynamic | Gentle control, maintains expressiveness |
| Dense | Compact, glued sound |
Additional Feature — Input Riding:
- Smooths slow level variations before compression
- Replaces manual fader riding
- Adjustable Speed (Slow/Medium/Fast) and Amount
Surround and Immersive Audio
| Feature | Pro-C 3 | smart:comp 3 |
|---|---|---|
| Surround Support | Up to 9.1.6 | Not documented |
| Dolby Atmos | ✅ Full support | ❌ |
| Channel Linking | Customizable surround controls | Stereo/M-S only |
Phase and Latency
FabFilter Pro-C 3
| Setting | Range | Notes |
|---|---|---|
| Lookahead | Off to 20 ms | Anticipates peaks, adds latency |
| Oversampling | Up to 32x | Reduces aliasing, increases CPU |
| Zero-Latency | ✅ | Disable both Oversampling and Lookahead |
Sonible smart:comp 3
| Mode | Latency | Phase Behavior |
|---|---|---|
| Minimum | Zero | Allows natural phase shifts |
| Linear | Added delay | Phase-coherent across spectrum |
💡 Use Linear phase for buses, parallel processing, and mastering where phase alignment matters. Use Minimum phase for tracking and live situations.
Multi-Instance Management
smart:comp 3 Group Mode
Organize up to 7 instances in a group for coordinated control:
| Feature | Description |
|---|---|
| Remote Control | Select any member to switch entire interface |
| Parameter Linking | Adjust ratio, threshold, attack, release, mix across all selected |
| Matrix Browsing | Adjust each member’s position from group view |
| Batch Learning | Trigger learning for all selected instances simultaneously |
Pro-C 3 Instance List
- Integrates with Pro-Q 4.10+
- Control Pro-C 3, Pro-G, and Pro-DS instances from Pro-Q 4’s interface
System Requirements
| Requirement | Pro-C 3 | smart:comp 3 |
|---|---|---|
| Windows | 7/8/10/11 (32/64-bit) | 10+ (64-bit only) |
| macOS | 10.13+ (64-bit) | 11+ |
| Processor | — | Intel i5 / Apple M1 minimum |
| RAM | — | 4GB minimum |
| Formats | VST 2/3, CLAP, AU, AAX | VST, VST3, AU, AAX |
| Apple Silicon | ✅ Native | ✅ Native |
| OpenGL | — | 3.2+ required |
When to Use Each Plugin
✅ Choose Pro-C 3 When…
- You prefer direct parameter control without learning phases
- Working with surround/immersive audio (up to 9.1.6/Dolby Atmos)
- You need extensive sidechain EQ with Pro-Q-style filters
- Coordinating compression across multiple FabFilter plugins
- You want 14 distinct compression algorithms immediately accessible
✅ Choose smart:comp 3 When…
- You want AI-assisted suggestions for unfamiliar source material
- Spectral Compression is needed within a single plugin
- Spectral Ducking would solve kick/bass or vocal/instrument conflicts
- Managing multiple similar sources (backing vocals, drum channels)
- You prefer semantic control (snappy/punchy/dynamic/dense) over technical parameters
Feature Comparison Summary
| Feature | Pro-C 3 | smart:comp 3 |
|---|---|---|
| Compression Styles | 14 algorithms | 4 engines + Matrix |
| Spectral Processing | Sidechain EQ only | Dedicated Spectral Compression |
| Saturation | Tube/Diode/Bright modes | Style-integrated |
| Sidechain EQ | 6 bands, Pro-Q shapes | Parametric/Shelving |
| Surround | Up to 9.1.6 + Atmos | Stereo/M-S only |
| Multi-Instance | Pro-Q 4 integration | Native Group Mode (7 instances) |
| Level-Independent | Auto Threshold | Input Riding |
| Zero-Latency | ✅ | ✅ (Minimum phase) |
| Learning/AI | ❌ | ✅ Compression Matrix |
Conclusion
FabFilter Pro-C 3 and Sonible smart:comp 3 represent different philosophies in compressor plugin design:
| Aspect | Pro-C 3 | smart:comp 3 |
|---|---|---|
| Approach | Traditional + Modern enhancements | AI-assisted analysis |
| Target User | Engineers who understand compression | Users wanting guided suggestions |
| Strength | Precise control, surround support | Spectral processing, semantic navigation |
Neither plugin is categorically superior. The appropriate choice depends on:
- Workflow preferences — Hands-on vs. guided
- Experience level — Technical knowledge vs. semantic understanding
- Project requirements — Surround needs, spectral processing, multi-instance management
Many professional studios maintain licenses for both plugins, deploying each where its particular strengths apply. Pro-C 3 excels in situations requiring precise traditional compression with extensive algorithm choices and surround support. Smart:comp 3 shines when spectral awareness and AI-assisted decision-making accelerate the workflow.
Both plugins demonstrate their respective developers’ commitment to professional-quality dynamic processing and represent the current state of compression technology in 2025.