2015: There have been many versions of front horns for 4" drivers... seven horns, ply, concrete, timber, some with multiple revisions of the throat.
Recovering from a computer death, not many measurements to share at present.
The graph below shows one crack at a system with a horn top (400Hz crossover), using a perfectly round throat. The better graph is the exact same horn, mic position etc, but with three felt dots added right at the throat. Breaking up the symmetry is enough to cut 3dB from the HF spikes.
Recovering from a computer death, not many measurements to share at present.
The graph below shows one crack at a system with a horn top (400Hz crossover), using a perfectly round throat. The better graph is the exact same horn, mic position etc, but with three felt dots added right at the throat. Breaking up the symmetry is enough to cut 3dB from the HF spikes.