Hornloaded

Hornloaded refers to loudspeaker systems that use a horn-shaped acoustic impedance transformer between the drive unit and the air. The horn gradually matches the driver’s impedance to the surrounding air, increasing acoustic efficiency and aiding directional control. While most commonly associated with compression drivers and horn-loaded enclosures, the term can also apply to horn-loaded subwoofers and certain drivers designed for constant directivity.

How it works: A driver converts electrical power into mechanical pressure, but without a horn much energy is wasted in impedance mismatch. A horn accelerates air more efficiently by providing a larger radiating area and a gradual impedance transformation from throat to mouth. The horn’s mouth size, throat size, flare rate, and length determine low-frequency cutoff, directivity, and overall sensitivity. Common horn shapes include exponential, conical, and tractrix, each offering different trade-offs in size and bandwidth.

Performance considerations: Advantages of hornloading include higher sensitivity (greater sound pressure with the same input power), extended throw with controlled dispersion, and improved impedance matching for high-frequency drivers. Limitations include larger physical size, reduced low-frequency extension compared to direct-radiating bass, potential coloration, and possible response irregularities if the horn is poorly designed or manufactured.

Applications and history: Horn-loaded designs have been prominent in professional sound reinforcement and cinema systems, where efficiency and controlled coverage are critical. They have also influenced certain high-end home audio products. Modern implementations often pair horns with waveguides or combine multiple horn sections to achieve wide, uniform coverage across a broad frequency range.