Advantages of B-Format Surround Encoding

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 (or three, in Impulse Response Utility) audio streams are all you need to capture audio from each speaker.

As an example, imagine you are using a five channel setup, and want to use Impulse Response Utility to create a five channel impulse response. Using traditional methods, you would need to record all five speakers from all five microphone positions, resulting in 25 audio files. If you choose to create your project as a five channel B-Format impulse response, you will only need to record 15 audio files—three audio recordings (W, X, and Y) from each of the five speaker positions. As you can see, B-Format encoded surround impulse responses require far fewer audio files, which means they require less hard drive space, as well as needing less RAM and CPU cycles when decoded in Space Designer.

A second advantage to 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 cancellations and phase shifts, which can affect the quality of your impulse response. As the point of reference is always the same when using B-Format encoding, there will be no phase issues, even when using multiple microphones to record your impulse response.