Creating Impulse Responses: A Practical Guide

By James Hartley · October 5, 2026

What Are Impulse Responses?

An impulse response (IR) captures the acoustic fingerprint of a physical space or piece of hardware. By convolving any audio signal with an IR, you can place that sound in the captured environment with remarkable realism. IRs power the reverb plugins used in every professional studio.

Equipment You Need

At minimum, you need a portable recorder with XLR inputs, a measurement microphone (omnidirectional, flat response), and a loudspeaker capable of reproducing a sine sweep or impulse signal. Popular measurement mics include the Earthworks M30 and Behringer ECM8000.

The Sine Sweep Method

The sine sweep method is the industry standard for IR capture. Play a logarithmic sine sweep (typically 20Hz-20kHz over 10-30 seconds) through your speaker and record the result with your measurement mic at the listening position. Software like Altiverb IR creator or the free REW (Room EQ Wizard) deconvolves the recording to extract the IR.

Positioning for Best Results

Place the speaker where a sound source would naturally be (stage, altar, front of room). Position the measurement mic at the listening position. For concert halls, capture multiple positions to build a comprehensive IR library. Keep the mic at ear height (1.2-1.5m).

Capturing Hardware IRs

You can capture IRs of analog reverbs, delays, and even EQ curves. Send the sine sweep through your hardware unit (input to output, no feedback loops) and record the return. This lets you use vintage hardware sounds in your DAW without the physical unit.

Post-Processing Your IRs

Trim silence from the start and end. Normalize to -1dB peak. Apply a fade-out to the tail if it contains noise floor artifacts. Save in WAV format at the same sample rate as your target project. Most convolution reverbs accept standard WAV files.

Building Your IR Library

Start with spaces you have access to: your studio live room, a church, a parking garage, a bathroom. Each space offers unique reverb characteristics. Label files clearly with space name, mic position, and date. A well-organized library becomes invaluable for sound design projects.