Altec 32C horn redux

Three years ago I replaced the Altec 811 horns with Altec 32C horns in my 2-way speaker system. I think I now have an unscientific explanation as to why I've been enjoying the Altec 32C.

Upper Left: Altec 32C, Upper Right: RCF H3709
Bottom: Altec 811

Somewhere along the way I acquired a pair of RCF H3709 horns. I was rooting for these horns because they resemble the Altec 32C but with a straight throat. The RCF H3709 to a much lesser degree, still exhibited some congestion and harshness I found objectionable in the Altec 811 in near field listening. Perhaps a judicious amount of damping applied to the thin walls of the RCF H3709 will significantly improve its performance. 

Top: Altec 811
Middle: RCF H3709
Bottom: Altec 32B/C

Based on the throat comparison picture above, I attribute the sonic superiority of the Altec 32C in my listening environment to its unconstricted and constant flare throat. But that's just my empirical observation ;)

Additional Information

Here's a quote from a post by Steve Schell at the Altec Lansing Forum

"...the initial throat portion of the H811b appears to have been designed to narrow the directivity of the high frequencies to partially equalize the on axis response. This is not a great solution for the falling power response of a compression driver, as the on axis response and reverberant field will vary greatly in high frequency content, which our brains interpret as unnatural. I would be tempted to model a horn similar to the 811 where the major flare portion maintains itself back to the driver aperture. The horizontal axis should (as designed) maintain the driver's power response to the limits of the straight horn walls, the driver's falling power response being EQed in the crossover, resulting in a more natural listening result. Just a thought, anyway."

Joe Roberts had nice things to say about the Altec 32A/B/C at the High Efficiency Speaker Asylum and Audiokarma.