Impulse Response Recording: Sine Sweep Method

This is the preferred method for creating impulse responses. It involves playing a broadband audio sine sweep into a space, and recording the sweep (and space) at optimal recording levels. A sine sweep that covers the entire audible frequency range is used, resulting in a broad-range, and often higher-quality, impulse response.

The recorded sine sweep audio file cannot directly be used as an impulse response. The recorded file contains all the echoes and reflections—in other words, the response—of the space, stretched out over the length of the sine sweep. This is very different from the starter pistol approach, where the response is contained at the beginning of the file in an impulse.

When you use a sine sweep, Impulse Response Utility uses a process called deconvolution to time align and level align all recorded reflections-that are present over the entire recorded sine sweep—into the very beginning of the file. This results in an impulse response that Space Designer can use to combine, or convolve, with your audio signal. Impulse Response Utility can then generate an .sdir setting from the impulse response.