Simple Explanation

How well a speaker or horn aims sound in a specific direction instead of spreading it everywhere.

Concise Technical Definition

In loudspeakers, directivity is the ratio (in dB) of the sound power radiated on-axis to the total power output across all directions at a given frequency.

Layman-Friendly Analogy

Like a flashlight focusing light in a beam—some speakers “beam” sound in one direction, others spread it out like a bare bulb.

Industry Usage Summary

Directivity affects how sound behaves in a room. Speakers with high directivity focus sound in one direction (useful for clarity in treated rooms), while wide dispersion is preferred in casual or home environments. Designers use polar plots to visualize this.

Engineering Shortcut

dB ratio of on-axis SPL vs. total radiated power—defines how directional a speaker is.

Full Technical Explanation

Directivity is a measure of how a loudspeaker distributes sound energy spatially. It describes how much sound is directed in a specific direction (usually on-axis) versus radiated into the rest of the space. It’s quantified using the Directivity Index (DI) in dB or the Directivity Factor (Q), which compare on-axis power to average power output. Directivity varies with frequency; high frequencies tend to beam more. Consistent directivity across frequencies is desirable for balanced room response. Polar plots or balloon plots are used to visualize a speaker’s directivity pattern.