Psychoacoustics and in room target response

The Physics of Perception:

Sound travels as waves, characterized by properties like frequency (pitch) and amplitude (loudness). Psychoacoustics delves deeper, examining how our ears and brains interpret these physical properties to create the auditory experience we know.

Key Concepts in Psychoacoustics:

Applications of Psychoacoustics:

The principles of psychoacoustics have numerous practical applications:

Practicals Studies

Dr. Floyd E. Toole studies indicate that listener tend to prefer a decay in the high frequency and a not abrupt change in the DI even if the DI should increase in very high frequency (so the speaker be more directive close to 7/8khz).


Bellow this very high frequency decay the radiation must be constant and controlled as lower as possible, without major accidents or diffraction.

With a horizontal polar in relative to 0°, it will looks like this, with no abrutp change when we lose the control in high frequencies:

ideal CD

As the horn has a radiation pattern that adapts to listening distance and room acoustics, while the woofer in direct radiation does not, their directivity characteristics diverge. To ensure a smooth transition and avoid an abrupt change in directivity, we perform the crossover (separation of frequencies between woofer and horn) at a point where their directivity patterns are similar as seen in Directivity Match article.

In practice, this crossover point often coincides with the point where the horn loses its wide directivity and the woofer starts to become more directional.

The main purpose here is to adapt coverage to listening distance and acoustics with no brutal change in Directivity Index.


Psychoacoustics plays a crucial role in shaping our auditory world.

By understanding the intricate relationship between sound waves and human perception, we can not only appreciate the science behind hearing, but also leverage this knowledge to improve sound design, enhance listening experiences.