Presentation' Slides (Power Point format)

* The three basic white excitation signals: Impulse, noise and sweep.
* The need for pre-emphasis in acoustical measurements.
* Methods of obtaining transfer-functions:
.......... Graphical plotter.
.......... Time Delay Spectrometry.
.......... FFT-based methods:
- -------------------------------Impulse,
- -------------------------------MLS,
- -------------------------------Pre-emphasized MLS,
- -------------------------------Arbitrary signals with length 2^n,
- -------------------------------Sweeps,
- -------------------------------Circular/linear deconvolution,
- -------------------------------Comparison of MLS and sweep-based TF measurements,
- -------------------------------vulnerability to time variance and harmonic distortion.

* Sweep synthesis:
.......... In time domain (lin/log sweep).
.......... In frequency domain:
- ---------------------------------Lin/log,
- ---------------------------------Creation of sweeps with arbitrary amplitude spectrum, but constant temporal envelope,
- ---------------------------------Creation of sweeps with arbitrary amplitude spectrum and controlled temporal envelope.

* Equalization of measurement loudspeaker:
.......... Measurement of acoustical power response.
.......... Multichannel sweeps with crossover functionality.

* Applications:
.......... Verification of sound reinforcement system response,
.......... Loudspeaker measurement in non-anechoic environment with 0-DC windowing,
.......... Loudspeaker impedance measurement,
.......... Calculating STI from IR.

Encontro realizado em 13/11/2003