Blackhole is a reverb algorithm on a truly galactic scale, originally debuting in Eventide’s DSP4000 Ultra Harmonizer before becoming a premier algorithm in the Space guitar pedal. The software plugin brings this legendary reverb to your DAW with its signature soft attack and lingering, harmonic tail that transforms any audio into otherworldly soundscapes.
Core Parameters
Mix
Controls the balance between dry (original) and wet (processed) signals. At fully counterclockwise (0%), you hear only the dry signal, though the reverb is still processing in the background. At fully clockwise (100%), you hear only the Blackhole effect with no dry signal.
Gravity – The Heart of Blackhole
Gravity is Blackhole’s equivalent of decay time, split into two distinct modes:
Positive Range (Right/Clockwise):
- Sweeps from short, dense decay to very long, smooth decay
- Creates traditional forward reverb
- Low settings: Short, bright reflections with strong articulation
- High settings: Long, cathedral-like reverb with defined attack
- Maintains articulation even during busy passages
Negative Range (Left/Counterclockwise):
- Creates inverse/reverse reverb effects
- Low negative settings: Smooth, connected reverse reverb tail
- High negative settings: Creates a gap between dry signal and pronounced inverse reverb peak
- The algorithm pulls the reverb tail into the original signal
Size
Controls the scale of the reverb space, from “cartoonishly small” to “cosmically epic.” Size has a symbiotic relationship with Gravity:
- Size scales the overall length of decay (or inverse decay)
- Gravity adjusts the behavior of the decay within that space
- Small size + low gravity = bright room reflections
- Large size + high gravity = cosmic, cathedral-like spaces
Predelay
Sets the delay amount before reverb onset (0-2000ms when Tempo Sync is off). The interaction with Gravity is crucial:
- Lower gravity settings smear the reverb onset
- Higher gravity settings create distinct echoes, like being in a canyon
- Available in tempo-synced divisions when Tempo Sync is enabled
Feedback
Takes signal from the entire reverb structure and feeds it back through the algorithm, extending sounds from huge to infinite:
- Adds density, warmth, and length to reverb
- Can introduce delay taps into the tail when combined with high gravity and predelay
- Infinite: Allows incoming signal into the reverb structure while holding the tail
- Freeze: Holds the reverb tail without allowing new input signal
Note: For pristine infinite reverb, either Mod Depth or Mod Rate must be set to 0.
Tone Controls
Low
Shelving filter controlling frequencies below 350Hz (-18 to +9dB). Use to add warmth or remove low-end rumble from the reverb tail.
High
Shelving filter controlling frequencies above 2000Hz (-18 to +12dB). Use to add airiness or tame brightness in the reverb.
Resonance
Controls the resonance of both Low and High filters. When filters are at center position, Resonance has no effect. With active filtering, it creates a resonant bump for more filtered sounds. Use carefully as extreme settings increase overload risk.
Modulation
Mod Depth
Built into the reverb algorithm itself, implemented as a multi-voice chorus effect:
- Adds warming characteristics to smooth harsh edges
- Settings below halfway: Subtle modulation
- Beyond halfway: Noticeable pitch bending begins
- Extreme settings can create straight chorus sounds (with Size at minimum and barely positive Gravity)
Mod Rate
Controls the speed of modulation:
- Works with Mod Depth to create movement in the reverb tail
- Higher rates with depth create dense, swirling textures
- Can smear the reverb tail into “galactic dust” at extreme settings
Performance Controls
Ribbon Controller
Allows dynamic control of multiple parameters simultaneously:
- Program left and right settings for any combination of knobs
- Morphs smoothly between programmed settings
- Responds to MIDI CC #1 (Modulation Wheel)
- To Program: Click white dots on knobs and drag to desired positions for left/right sides
- Alternative: Press Ribbon buttons and adjust knobs to desired positions
Kill
Cuts input to reverb section while allowing the tail to fade naturally:
- Useful for dialing in sounds or creating tremolo-like effects
- Controlled via MIDI CC #2
Hotswitch
Instantly toggles between two complete settings:
- To Program: Hold button until ring blinks, adjust all desired parameters, press again to save
- Toggles between off-state and programmed values
- Controlled via MIDI CC #3
Freeze
Quick access to infinite reverb:
- Sets reverb time to infinite
- Sets Feedback and Mod Depth to “Freeze”
- Mutes input signal
- Controlled via MIDI CC #4
Input/Output Controls
In
Controls input level (-60 to +12 dBfs) for both wet and dry signals.
Out
Controls output level (-60 to +12 dBfs) after the mix control.
Meters
Display audio levels before and after the reverb algorithm to aid in level adjustment.
Overload Indicator
Shows when the reverb’s signal chain is overloading. Click to clear this sticky indicator.
Tempo Sync
Controls how Predelay responds to tempo:
- Off: Predelay in milliseconds (0-2000ms)
- Sync: Syncs to DAW tempo in beat divisions
- Manual: Syncs to manually set tempo in beat divisions
Creative Applications
Traditional Reverb Sounds
- Small/medium Size with positive Gravity for halls and rooms
- Use EQ controls to shape character
- Subtle modulation for plate-like sounds
Otherworldly Soundscapes
- Large Size with extreme positive Gravity
- Experiment with Feedback for infinite spaces
- Use negative Gravity for reverse effects
Sound Design
- Freeze function for sustained textures
- Extreme modulation for chorus-like effects
- Ribbon programming for dynamic morphing between settings
Tips for Best Results
- Start Simple: Begin with moderate Size and Gravity settings, then experiment
- Use EQ Creatively: The filters shape the reverb character significantly
- Modulation Balance: Subtle modulation warms; extreme settings create special effects
- Infinite Reverb: Turn Mod Depth or Rate to 0 for clean infinite tails
- Performance: Program the Ribbon and Hotswitch for live parameter changes
- Level Management: Watch the overload indicator and adjust input levels accordingly
MIDI Control Summary
- CC #1: Ribbon Controller (Modulation Wheel)
- CC #2: Kill function
- CC #3: Hotswitch toggle
- CC #4: Freeze function
The Blackhole plugin excels at transforming ordinary sounds into extraordinary soundscapes, from subtle spatial enhancement to completely otherworldly effects. Its unique Gravity control and the symbiotic relationship between Size and decay behavior make it capable of sounds no other reverb can achieve.
