Feed the EQ output to your sound card channel 2 input. As an experiment, I miked an acoustic guitar with one microphone two feet away as a reference and plugged it into channel 2. I also miked the guitar with an identical microphone close to the sound hole, and plugged it into channel 1. This feature alone makes Smaart Pro an educational tool for microphone designers and recording engineers. Another measurement is coherence, or correlation, between two signals.
Coherence is used to check the quality of the transfer-function data.
Additionally, Smaart Pro can determine the delay between two input signals. This function lets the user measure the delay of a signal processor, or the sound travel time from speaker to microphone. Note that Smaart Pro compares a reference signal to a measured signal. For most measurements, these two signals must align in time. If you measure a loudspeaker with a microphone, the microphone's signal is delayed due to the sound travel time from speaker to microphone.