Definitions for "Critical Distance"
The term “critical distance” refers to the distance from a loudspeaker in an enclosed space at which the reverberation is equal in strength to the direct sound from the speaker. Beyond this distance, the reverberant energy tends to mask the direct sound. In truth, because reflected sound loses energy to boundary absorption (and also travels a longer path to the listener, thus incurring greater air absorption losses), the reverberant energy from a discrete pulse sound stimulus can never equal the direct sound on an instantaneous basis. In highly reflective environments, however, the steady-state reverberation strength can easily exceed that of the direct sound at many locations in the space. This degrades the signal-to-noise ratio and destroys intelligibility. Return to
The distance from a sound source at which the reverberant sound is equal to the direct sound. A very reverberant room has a short critical distance while an acoustically dead room can have a much longer critical distance. Room treatment types and speaker choice affect critical distance.
The point from the sound source where the direct sound and the reverberant sound are equal in volume
Keywords:  crossfade, crossover
Crossfade Crossover
Furthest point from which an object can be visually discriminated