ABSTRACT
It is important to remember that in evaluating loudness measurement schemes, the reference has been a purely subjective judgment. Measurements include sounds reflected or diffracted from seats causing irregularities from phenomena that appear not to be bothersome to listeners. Measurements in anechoic chambers are straightforward. Measurement microphones are pressure devices, and high-quality ones are delivered with calibration curves. At low frequencies true steady-state measurements are needed, and high resolution allows for the identification and treatment of room mode problems. If the loudspeakers are portable, it is possible to greatly improve the frequency resolution of these pseudo-anechoic measurements by transporting them to a situation where the reflection-free time window can be extended. In the absence of anechoically measured data on the loudspeakers, it is possible to perform quasi-anechoic measurements in the venue. Sounds arrive at the microphone from multiple directions simultaneously, and in multichannel systems loudspeakers are located at various angles to the measurement point.
