Reducing dispersion angle

Rotate the horn, its 80 deg by 50 deg

Edited by Jan-2T - 21 August 2025 at 3:53pm

I am looking to reduce the dispersion angle of my speakers. Are there some dirty tricks I can look at to achieve this? Barn doors, some sort of phase-pluggery, etc?

The simple answer is no. Barn door will have some effect, but probably not what you are hoping for.

Rotate the horn, its 80 deg by 50 deg

This has no effect on the low/mid cone drive unit

Put another HF horn on top and filter the HF out of your speakers?

See above.

The rated box dispersion is a lie or is at least isn't the whole truth, it only aplies to the HF horn output…….

This, sort of.

…..the woofer is omni directional over much of its range.

Low frequency drive units get directional at quite low frequencies. There is no well defined cut off, but the nominal frequency, depending on who you talk to, happens where the value Ka is between 1 and 2. Ka = 2πa/λ and a is the effective radius of the drive unit.

For a 15” drive unit Ka = 1 is roughly 300 Hz.

This is approximately where the on axis spl is about 6db above what it would be if the source was radiating omni-directionally.

To really get controlled dispersion over the box's whole output range all drivers have to be horn loaded.

Arrays are another means of controlling directivity. With a single cone, directivity basically comes down to its size. There are a few ways around it, but if implemented would likely a publicised selling feature.

3d print some wave guide inserts.