Horn Design
This webpage is my possibly incoherent attempt to explain how I design horns - all kinds of horns. It is an evolving document, changing every time I feel like working on it. It assumes basic knowledge of speaker design and terms.
Opening notes:
Sometimes it seems there is a disconnect in people's minds between a cone driver loaded by a horn and a compression driver loaded by a horn. This is probably caused by two factors. One is that cone driven horns are usually designed starting with the Thiel / Small parameters of the driver while the T/S parameters are usually not available for a high frequency compression driver. The second is that the directivity characteristics usually play a much larger role in determining the on-axis frequency response for a high frequency horn than they do for a low frequency one. Since freely available software does not usually predict this effect, people see predictions of high frequency horn performance as unrealistic. However both setups are really the same thing - a diaphragm of some sort driving a horn with a front and rear chamber. The details of how a hobbyist would design and assemble these systems are just a bit different.
I attach importance to these factors in designing any speakers, but specifically horns:
- Smoothness of frequency response
- Smoothness of power response (response at all angles)
- Tonal balance (how flat the frequency response is)
- Low distortion at the expected maximum playback level
- High efficiency (to reduce power compression for a given playback level)
- Time alignment (usually not a big deal for cones, but worth mentioning with large multiway horn systems)