Horn based loudspeakers why the controversy?

I had a pair of home version Altec A-7's (846B Valencia) back in the early 70's. They were dynamic, had gobs of mid-bass. Problem was, their response curves were very ragged, and the high frequencies fell off quite rapidly above 12k. They also had a very upfront forward soundstage. I moved on to higher quality audiophile speakers after that. Yes, I know, I could have used better amps with them as I used all SS back then, but the overall colorations of those speakers were too hard to endure for the long run. I do agree the latest horn based systems have probably come a long ways vs. those old designs. I just haven't taken the time to listen to them. Much of what I said above could be said for the old JBL and Klipsch designs too......

I believe any and all Altec compression drivers had phase plugs. They changed some of their characteristics  (Tangerine) to extend and smooth out high frequencies.
Cheers, 
Tim

Compression drivers of all types, from what I remember, had a phase plug. The Tangerine came later, (mid 70's) first used in the Altec Model 19. The phase plug was needed to make the compression driver work properly. I don't know the mechanical or electrical reasons why. I think Altec came out with the Tangerine because one of the chief complaints about these drivers was a lack of HF extension. I remember my home pair of A-7's having more of a "whoooshhh" sound  on cymbals rather than the nice extended "crash" sound a cymbal has when struck with a stick or mallet. This was much improved with the Model 19. IMHO

Willland
Look in the A'gon speaker classifieds. There is a pair of Klipsch P-39f Palladiums there right now.