Manual: I3DL2Reverb Plugin

I3DL2Reverb plugin window

The I3DL2Reverb plugin is an advanced reverberation processor based on the Interactive 3D Audio Level 2 (I3DL2) specification. This reverb can simulate various acoustic spaces and environments, offering control over early reflections, reverb tail characteristics, and frequency response. Various presets from the I3DL2 specification are provided as starting points for your own reverb parameter design.

Note that this plugin outputs only the “wet” reverb signal, so enabling the “Dry Mix” option is recommended.

Parameters

Room

• Controls the overall level of the reverb and thus allows to balance it against the dry signal. Higher values (closer to 0 dB) produce louder reverb, while lower values result in a more subtle reverb effect.
• Range: -100 dB to 0 dB

Room HF

• Adjusts the level of high-frequency content in the reverb. Lower values create warmer, more muffled reverb by reducing high frequencies, simulating absorption by soft materials like carpet or curtains. Higher values preserve brightness in the reverb tail, sounding more airy and artificial.
• Range: -100 dB to 0 dB

RoomRolloffFactor

• This parameter does not do anything. It only exists for backwards-compatibility with the original DMO plugin.

Decay Time

• Sets the time it takes for the reverb to decay by 60 dB. This is the fundamental parameter that determines the size of the simulated space. Shorter reverb times simulate a smaller room, while longer reverb times create the impression of expansive, cathedral-like spaces.
• Range: 0.1s to 20s

Decay HF Ratio

• Determines the ratio between the decay of high frequencies and low frequencies. Values less than 1 make high frequencies decay faster than low frequencies, creating warmer, more natural-sounding reverb. Values greater than 1 make high frequencies decay slower, creating a brighter, more airy and artificial reverb.
• Range: 0.1 to 2.0

Reflections

• Sets the level of early reflections, which are the first echoes that reach the listener after bouncing off nearby surfaces, providing spatial cues about room size and shape. Higher values make the space sound more reflective.
• Range: -100 dB to +10 dB

Reflections Delay

• Controls how long it takes until early reflections are heard. Longer delays suggest larger spaces with more distant walls, while shorter delays indicate a smaller space.
• Range: 0s to 0.3s

Reverb

• Adjusts the level of the late reverb tail, which is the dense mix of reflections that creates the sustained reverb sound. This parameter controls the prominence of the reverb tail relative to the early reflections and direct signal.
• Range: -100 dB to +20 dB

Reverb Delay

• Sets the delay between the early reflections and the onset of the late reverb tail. The gap between early reflections and late reverb helps define the perceived size and shape of the environment. Longer delays make the reverb sound more distinct from the source.
• Range: 0s to 0.1s

Diffusion

• Controls how quickly the echo density builds up in the reverb tail. Higher diffusion values create smoother, more even reverb with less distinct echoes. Lower values preserve more of the individual reflections, which can sound more spacious but less smooth.
• Range: 0% to 100%

Density

• Determines the spread in time between individual reverb delays, affecting how thick or sparse the reverb sounds. Higher density values create fuller, more lush reverb, while lower values produce thinner, more metallic reverb.
• Range: 0% to 100%

HF Reference

• Sets the reference frequency that defines what is considered “high frequencies” for the Room HF and Decay HF Ratio parameters.
• Range: 20 Hz to 20,000 Hz

Quality

• Selects the reverb quality, directly affecting CPU usage by the plugin.
• Options: LQ, LQ+, HQ, HQ+
  • LQ: The reverb is downsampled for processing, fewer delay lines are used.
  • LQ+: The reverb is downsampled for processing, more delay lines are used.
  • HQ: The reverb is processed at the original sample rate, fewer delay lines are used.
  • HQ+: The reverb is processed at the original sample rate, more delay lines are used.