What is swept sine measurements, swept bandpass filters and time delay spectrometry all about?
To analyze the frequency response (in magnitude and phase) of a system, sine signals with variable frequency have proven useful. It is of interest how swept sine sweeps and sine signals with an arbitrary overall frequency spectrum are generated and what to bear in mind when doing measurements. Furthermore, harmonics and noise rejection can be accomplished using a bandpass filter whose center frequency tracks the momentary frequency of the swept sine with a delay to accomodate for propagation delay. All this is covered in the paper by Swen Mller and Paolo Massarani linked below. From the abstract: Compared to using pseudo-noise signals, transfer function measurements using sweeps as excitation signal show significantly higher immunity against distortion and time variance. Capturing binaural room impulse responses for high-quality auralization purposes requires a signal-to-noise ratio of >90 dB which is unattainable with MLS-measurements due to loudspeaker non-linearity but fairly easy t
