What does one purchase after owning horns?

Mapman wrote: "The primary benefit of horns is efficiency."

No doubt I'm in the minority here, but my primary reason for using horns (waveguides being a type of horn) is radiation pattern control.

radiation pattern control lack of distortion and efficiency

"lack of distortion"

That's a tough case to make in reality I think.

I'll buy radiation pattern control as a another unique attribute of potential benefit.

Shadorne you do not mention SPL level for conventional design distort much when near max SPL.

John - yes that is true. I was just passing on info on horns. In conventional designs if you need higher SPL and need good linearity then big and beefy drivers with pro voice coils and magnets are the ticket. In the case of horns however there is a fundamental difference because the non-linearity comes from non-linear air compression in the chamber - so it is an inherent issue that can change the way the sound is compressed as a function of SPL and frequency. As I mentioned, I think it is clear from the JBL paper - these problems are more significant in very high efficiency horns (greater compression) and long horns with narrow flare. AG horns are both efficient and have a long narrow flare - so it may help the OP achieve better bass integration to consider other less "aggressive" horn designs with wider flare and lower efficiency.

Just a thought....every design has its pros and cons and the OP has clearly stated why horns sound so good (the pros).

Shadorne, Klipsch uses the "non aggressive" horn type you mention. However, because of the horn type AG uses, I find the seated distance between them and the listener needs to be greater,ime. However I have "heard" this rule be broken in many cases. I have heard many Lascalas (and Khorns for that matter)in which the owners have changed out the mid horn(to Altecs mostly)and I have not liked it as much as the original. I felt it threw the balance and coherence off. Other things as well. All of these horn designs were available to PWK, but I think he made excellent choices for his models. I know it is a matter of personal taste.