Mid-range beaming and narrowing

The Challenge of Midrange Response

In loudspeaker design, achieving a smooth and balanced frequency response across the entire spectrum is a continuous pursuit. One specific challenge lies in the midrange frequencies (typically around 1 kHz).

Here, two unwanted phenomena can significantly impact the sound and his power response: midrange narrowing and beaming.

Here we can see a not fully optimised end of profile resulting a narrowed mid-range in 1kHz region :

ideal CD

Whatever the horn, wageguide, integrated on baffle or not, the contour must be fluid in all directions.

Here is a very good elliptic waveguide with a slightly rounded traditional baffle where mid-range beaming and mid-range narrowing are still visible :
ideal CD
Then the same wave guide (but 0.5" tinier) integrated with a fluid profile :

ideal CD

Midrange Narrowing: A Dip Caused by Diffraction

Midrange narrowing refers to a decrease in sound pressure at specific midrange frequencies.

This occurs due to edge diffraction. When sound waves traveling from the driver encounter the sharp edges of the speaker baffle, they bend around these obstacles.

This bending disrupts the wavefront, causing destructive interference at certain wavelengths (frequencies). These wavelengths correspond to the dip observed in the midrange response of the speaker, affecting both on-axis and off-axis.

Here is an exemple about how to solve it:

next gen bi-radail

Midrange Beaming: Uneven Radiation Due to Diffraction

While midrange narrowing represents a loss of sound pressure, another effect of edge diffraction is midrange beaming. This phenomenon describes the concentration of sound pressure in specific off-axis directions.

The bending of sound waves can lead to constructive interference at certain angles, resulting in peaks in the off-axis response. However, in other off-axis locations, destructive interference can occur, causing dips.

This creates an uneven sound radiation pattern, compromising the overall soundstage and affecting listeners at various positions.

The Impact on Listening Experience

The combined effects of midrange narrowing and beaming can significantly alter the way we perceive sound. Here’s how:

Optimizing Baffle Design for Smooth Midrange

To address these challenges and achieve a smooth midrange response, loudspeaker designers employ various strategies:

4mm radius

For flat baffles, a simple round-over return might not be sufficient. In those cases, designers may employ profile acceleration and deceleration, this involves a gradual transition from the horn’s curvature to the flat surface of the baffle, minimizing the impact of abrupt changes on the wavefro

Advanced Design Techniques

Modern loudspeaker design tools like Finite Element Analysis (FEA) simulations allow for precise modeling of baffle shapes and their impact on sound radiation. This facilitates the optimization of baffle profiles to minimize diffraction effects and achieve a smooth, balanced midrange response.


Understanding midrange narrowing and beaming caused by edge diffraction is crucial for achieving optimal sound quality in loudspeakers. By employing careful baffle design techniques and advanced simulation tools, designers can create speakers that deliver a natural and detailed listening experience across the entire frequency spectrum, for both on-axis and off-axis listeners.