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In the Forum: Audio Discussions
In the Thread: A listening room for a domesticated Cat?
Post Subject: Two separate individualsPosted by martinshorn on: 7/13/2017
priviet. I tried many ways. I cut the front outside faceplate open, and put a second driver on it. So that two drivers were firing onto each other face to face in one single hornthroat, rest normal single K. To my surprise the output didn't increase at all. Neither response. No clue where the energy went.
Expected enlarging the throat might help but didnt. Then the horn was demolished 
Couple of other mods on the mouth continued as failures.
Starting over. Taking the right khorn, so one complete individual horn, and just lifted it up on top of the other. That worked amazing! The nearfield measures showed 2 big notches in the fundamentals though. Probably what you meant by having a unsteady phase on the wavefront. But well, who listens with the head in the corner. At about 2 Meters distance it got the way it was supposed to be. The further the better. The whole response curve lifted equally 6dB with a slight bottom extension of a view cycles.
I assume this must be connected to minimum listening distance to the mouth in correlation to the mouth size. Unless you got waveguides like some do for HF in PA. Luckily the K's actually have 2 vertical slits on top of each other approaching the corner wall. So its already slightly guiding the waves with a period of 48cm / 358Hz which was where the lowest notch appeared in nearfield roughly. Long story, the vertical slits add nicely to a vertical cylinder wave, and once you're at least 2-3 meters away you get great response. 1 Meter collapses in the fundamentals.
So no fear in normal listening distance its al good in phase. Just double the efficiency. Which is a lot imho.
PS: the height of the sound image is just right. At least my ears sitting r at 92cm height. The Ks are 97 hi, stacking two is 198+ but the center is again exactly on height of your ears. Its like made for stacking Rerurn to Romy the Cat's Site