Why not horns?

:-) HUP! HOLLAND HUP! :-)

Learsfool, I don't have first-hand experience with the A7, but it seems to me that there might be a step-down in response below the frequency were the short horn in front of the woofer un-loads, such that in the bass region the response might normally be down a few dB relative to the midrange and above. This may be compensated for in the crossover, or it could be offset by boundary reinforcement with appropriate placement. Lacking that short horn in front of the woofer, the Model 19 would probably be a bit lower in overall efficiency but would not have a potential step-down between the midrange and bass region.

Perhaps the primary innovation of the Model 19 was moving the crossover frequency up to 1200 Hz. This seems rather counter-intuitive, but what it did was allow pattern-matching in the crossover region. At 1200 Hz the woofer's pattern had narrowed sufficiently to match that of the horn, so there was no discontinuity in the off-axis response. The "manta ray" horn had constant directivity in the horizontal plane above the crossover point. These are worthwhile characterisics because in many listening situations the off-axis response strongly influences or even dominates the perceived tonal balance, though I think horn design has advanced since then. Wayne Parham, Earl Geddes, and yours truly embrace constant directivity and pattern-matching in the crossover region.

A few years after the Model 19 was introduced, JBL designed a studio monitor, the Model 4430, with strong emphasis on pattern-matching in the crossover region as well as constant-directivity above the crossover region. I would not be surprised if the Model 19 was one of their primary inspirations. While the horn geometry is quite a bit different, the basic concept is similar to that of the Model 19. Here's a link to an Audio Engineering Society paper written by the designers of this speaker:

The landmark JBL Model 4430 studio monitor

Duke

Interesting article, Duke, although much of it went over my head.

I've seen a lot of references over the years to the JBL K-2 and Everest speakers as if they represent a pinnacle of speaker design. Do you know anything about them and how well they stand up to other statement speakers?

Here we are at half-time in the World Cup Final and I have to revise a comment I made a while ago. I called the Dutch physical. After watching a half where they should have wound up playing with only 9 guys on the field, I want to say that the Dutch are a chippy, chickensh*t, cheating bunch of thugs. Hup yours, Holland.

Thanks, Macrojack. Since posting the link, I have "met" one of that paper's authors in another online forum (he and I are disagreeing about something... surprise surprise!).

I don't have any experience with either the K-2 or Everest, but I'm sure they're awesome.

The original Everest, circa 1985, used an asymmetrical horn to achieve the desired toe-in angle without having to actually toe the speakers inward:

Original JBL Everest

I borrowed the concept; one of my models uses asymmetrical enclosures to achieve the same end, but with a conventional symmetrical horn.

Duke