Alternative recording setup for Impulse Response Utility
It is possible to make discrete multitrack impulse responses even if you do not have enough speakers or microphones to do so in one pass. In this situation, you record one sine sweep at a time in Impulse Response Utility, using as many speakers as you have, then move the speakers to new positions and repeat the process. For example, imagine you have a stereo pair of speakers but want to create a quadraphonic impulse response, which requires recording four tracks in four different speaker positions. You could set up your pair of monitors, record their output, then move them to record the other pair of tracks in the other two speaker positions.
This method of creating impulse responses is time-consuming, and not having all speakers required for the format makes it difficult to place speakers in the optimal positions, relative to each other. With time and careful planning, however, you can still achieve the same results as would be possible with an ideal complement of speakers.
You can also create multichannel impulse responses in Impulse Response Utility by using a mono or omni discrete impulse response format. This requires you to record one speaker with the number of “channel” microphones required for the chosen format. The resulting impulse response places a lower strain on your CPU. See Record audio in Impulse Response Utility.
If you have enough monitors but not enough microphones, you can set up the required speakers and then move your available microphones between them. This makes it difficult to place microphones in the optimal positions, relative to other microphones, but you have the advantage of optimal speaker placement.
If your audio interface does not have the required number of inputs and outputs for the speakers and microphones you are using, you can still set up all microphones and speakers. As you record different tracks in Impulse Response Utility, you will need to disconnect and reconnect the speakers and microphones in turn.
Download the guide:
Impulse Response Utility User Guide: Apple Books