Wayne, Dr Geddes -

If you splay two axisymmetric horns, wouldn't you get massive comb filtering? I've never tried this, but I assumed that the frequency response would be practically unusable.

As you know, I use horns and waveguides in cars, and in this environment, vertical size is severely limited.

I've considered oblate bispheroidal as well, but assumed that it would suffer from the same comb filtering. And OBS waveguides are all but undocumented.

Patrick Bateman

• this is what a horn looks like in a car