mrdecibel, I have appreciated your input over the years while looking for ways to improve my sound system, even beyond speakers, so thought I'd add some clarity on the dampening mod. I understand some horn and speaker combinations can yield better results for the same mod. Long throat metal horns like the Altec 811b or RCF H3709 can benefit from dampening (and if using an 811b and the cabinet extends past the sides of the horn, be sure to use foam on the cabinet like Altec did on the Model 19).
As mentioned, I replaced the Forte I midrange compression driver with the earlier Heresy's, and at that time I also purchased the Heresy horns, model K-701. The driver was a construction quality and sonic improvement. However, I was surprised that the earlier K-701 horns lacked much of the outside molded webbing for structural support compared to the late 1980s versions in the Forte I (and I assume Heresy speakers of that timeframe.) Tapping them showed a marked difference in ringing and sustain with the webbed horns obviously being better damped.
So I kept and applied damping material to the webbed horns. Also, as mentioned, made sure the horn gasket was in place and the horn properly tighten to the baffle, something far more important.
For me, with this speaker, the other earlier performed mods were more noticeable improvements. The "no appreciable difference" would have been based on that. It may have also been because of additional work on the cabinets, like having them properly sealed, etc., had also already been done.
However, I appreciate that the damping material could play a large roll in the results. I used 1/4" Dynamat dense foam sound deadener because I had very good results when used to quite interiors of classic cars. All of the horn's outside surface area, including in between the webbing, was covered. How does that compare to your method?
As far as the sound of Klipsch speakers, or any high efficiency horn loaded speaker combination like older Altecs, part of the enjoyment is the particular sound and dynamic range they give. If that's what the original poster prefers, great, then follow that path and include tubes electronics to make the most of it. To each their own, but remember that most albums of any type of music in the 1960s and 1970s were mixed listening through 2-way monitors with horns by Altec, and were good enough for The Beatles and Mr. Martin. (Not trying to start a debate of point source studio monitors vs. loudspeaker).
