I listened to the large Bionor horns every day at @ddk 's place over a week long visit and the sound was great regardless of where in the room one sat. No need to be in the one and only central seating position for good sound. I did not get the sense that it was very directional. I don't know if Avantgarde's are different, but I don't think one can generalize about this aspect of listening with all horn designs. Perhaps it was something else in ddk's system that contributed to this sense of envelopment regardless of seating or standing position.
Exactly Peter. When people talk about “horns” it really is unfortunately misleading because they are such a heterogeneous breed. The vintage speakers like Bionor (and WE designs) excelled at filling large places as that was their entire purpose. There are certain types of horns that are designed for wider listening angle such as the multi cells you see ubiquitously on the cinema designs of yesteryear (Altec et al). By the way I am not saying that “horns” can be very directional - they can. My Swings were very much that way which suited me and my room but others would be less enamoured.
Best.