Advantages of B-format surround encoding in Impulse Response Utility

One advantage of the B-format is that it can capture a surround image with fewer audio files. Normally, you need to record every speaker position from every microphone position to correctly record surround information. With B-format, these four audio streams are all you need to capture audio from each speaker.

For example, imagine you are using a five-channel setup and want to use Impulse Response Utility to create a five-channel impulse response. If using traditional methods, you need to record all five speakers from all five microphone positions, resulting in twenty-five audio files. If you choose to create your project as a five-channel B-format impulse response, you need to record only twenty audio files—four audio recordings (W, X, Y, and Z) from each of the five speaker positions. This clearly illustrates that B-format encoded surround impulse responses require far fewer audio files, and therefore less hard drive space, as well as needing less RAM and CPU cycles when decoded in Space Designer.

A second advantage of B-format encoding is phase coherency when using multiple microphones at once. Whenever you use multiple microphones, differences in the time it takes sound to reach each microphone can result in phase cancelations and phase shifts that can affect the quality of your impulse response. Because the point of reference is always the same when using B-format encoding, there are no phase issues, even when using multiple microphones to record your impulse response.