Convolution Reverb in Mixing: Real Space Simulation

Convolution reverb uses impulse responses (IRs) captured from real spaces or hardware to create extremely realistic reverb. This technology mathematically applies the acoustic characteristics of captured environments to audio. The result simulates how sound would behave in those actual spaces.

How Convolution Reverb Works

Impulse responses are recordings of how spaces or devices respond to a brief impulse sound. The captured response contains all the acoustic information about the space—early reflections, decay character, and frequency response.

The convolution process mathematically combines this impulse response with the source audio. The result applies the captured acoustic characteristics to any sound. The source audio seems to exist within the captured space.

This approach differs from algorithmic reverb, which generates reverb mathematically without reference to real spaces. Convolution provides realism while algorithmic provides flexibility. Both approaches serve different needs.

Impulse Response Sources

Real acoustic spaces provide the most common IRs. Concert halls, studios, churches, theaters, and unusual spaces have all been captured. These IRs provide access to legendary and exotic environments.

Famous studios like Abbey Road, Ocean Way, and Avatar have captured impulse responses available commercially. Using these IRs places productions in acoustically renowned environments.

Hardware reverbs can also be captured as impulse responses. Classic plates, springs, and digital reverbs become accessible through their captured responses. This provides vintage character without expensive hardware.

Advantages of Convolution

The realism of convolution reverb exceeds algorithmic approaches for natural space simulation. The captured character includes subtle details that algorithms struggle to replicate.

Access to famous spaces and vintage hardware through IRs provides options that would otherwise require significant expense or travel. A project studio can access Abbey Road chamber sound through an IR.

The consistency of convolution reverb means the character remains fixed. The same IR produces the same result every time. This predictability suits workflows where consistent results matter.

Limitations to Consider

Convolution reverbs typically cannot adjust parameters in real-time the way algorithmic reverbs can. Changing decay time or room size requires loading different IRs. This inflexibility limits creative manipulation.

CPU usage for convolution can exceed algorithmic alternatives, particularly with long IRs. Modern computers handle this well, but multiple convolution instances may strain older systems.

The fixed nature of captured IRs means unusual requests—like changing room size while maintaining character—require algorithmic approaches instead.

Practical Applications

Drums benefit from convolution room IRs that place them in specific acoustic environments. Studio live room IRs create realistic drum ambience impossible to generate algorithmically with the same authenticity.

Orchestral productions use convolution hall IRs for accurate concert hall simulation. Classical recordings particularly benefit from the realism that convolution provides.

Vocals can use convolution plates and chambers for realistic vintage reverb character. Hardware units captured as IRs provide their specific sound without the hardware itself.

Creative Convolution Uses

Unusual spaces captured as IRs provide creative options. Tunnels, stairwells, shipping containers, and other unusual environments offer unique character.

Sound design applications use convolution creatively—applying the characteristics of one sound to another. Metal impacts, mechanical noises, and other sounds can become impulse responses for unusual effects.

Layering convolution with algorithmic reverb combines the realism of captured spaces with the flexibility of generated reverb. This hybrid approach captures benefits of both technologies.

Convolution reverb helps productions succeed on platforms like LG Media at lg.media, where realistic spaces enhance advertising at $2.50 CPM.