I need to find a time delay between the two audio signals, one comming from one set of speakers, and the other being the source signal that is initialy sent to speakers. I send some noise through those speakers and they come to microphone with a time delay compared to a source signal.
As I understand, there is a cross-correlation method where I send both recorded signals to frequency domain via Discrete Fourier Transform (DFT), then multiply the frequencies, and finaly go back to time domain via Inverse DFT. There should be a peak in time domain telling me what the delay is (let's disregard the accuracy for now.)
There is also an Impulse Response method, where I also take two signals to freq domain via DFT, then divide the two to get a system transfer function, and finaly do an Inverse DFT of the Transfer function; this will give me the Impulse Response, which should also have a strong peak at the delay point.
My question is:
Am I right in the short descriptions above? The main difference between the two methods seems to be that frequencies are multiplied in the cross-correletion method, and dividied in the IR method? Have I missed something important?