Fundamentals of modern audio measurement

Fundamental concepts in testing audio equipment are reviewed, beginning wit h an examination of the various equipment architectures in common use. Seve ral basic analog and digital audio measurements are described. Tradeoffs in herent in the various approaches, the technologies used, and their limitati ons are discussed. Novel techniques employing multitone signals for fast au dio measurements are examined and applications of sampling-frequency correc tion technology to this and conventional fast Fourier transform (FFT) measu rements are covered. Synchronous averaging of FFTs and the subsequent noise reduction are demonstrated. The need for simultaneity of digital and analo g generation is presented using converter measurements as an example.