The AV industry has a language problem. We describe sound using the vocabulary of light. We talk about speaker “coverage” like it is the beam of a spotlight. Hard edges. A defined pattern. Point it at the seats and the job is done.
Sound does not work that way. A spotlight’s beam is essentially the same shape across the visible spectrum. A loudspeaker’s pattern is not. Dispersion changes with frequency, and it changes dramatically. A box rated at 90 degrees might hold that pattern at 2 kHz, narrow toward 40 degrees in the high end, and lose pattern control entirely below a few hundred hertz where the wavelength outgrows the device. There is no single coverage angle. There is only coverage at a frequency.
Then the room gets involved. Light, for our purposes, travels and stops. Sound keeps going. It reflects off the first surface it finds, then the second, then the third. It bends with temperature gradients. It is absorbed unevenly by humidity, by materials, by the audience itself. The direct sound is only the beginning of what a listener actually hears.
Acoustic modeling helps. Good modeling software predicts direct coverage, early reflections, and reverberant behavior with real accuracy. But a model is a prediction, not the room. Temperature shifts during an event. A full house absorbs differently than an empty one. The model is a strong starting point and a poor finish line.
So when someone hands you a coverage pattern, the first question is “at what frequency.” And the honest follow-up is that even the full frequency-dependent answer does not tell you what the room will do with it.
The room is part of the system. Designing audio well starts with accepting that.
Complex systems. Seamless experiences.