ABSTRACT
This chapter looks at the behaviour of multiple loudspeakers. If the high and low frequencies are equal in level on-axis, then it should be obvious that in the room as a whole, there will be more low-frequency energy, because at no point do the high-frequency levels exceed the low-frequency levels. The chapter considers two ideal monopole sources, representing a stereo pair of perfectly flat, omni-directional loudspeakers. On 'steady-state' signals, the situation can be very different between anechoic and reverberant rooms. On the central plane of a stereo pair of loudspeakers, the transient pressures will also sum, producing a single pulse of sound 6 dB higher than that emitted by each loudspeaker individually. In stereo radio drama, where voices are often panned across the sound stage, −3 dB pan-pots would produce a uniform level as a voice was panned from left, through centre, to right.
