Can you describe more detail how the sound changes with the vertical dispersion when you stand up and sitting on the listening position to the various distance (for example, 5 to 12 feet) from the speaker? I wanted to know if it will work on my living room and the listening distance is 9 feet to 11 feet. Thanks.
@drumdoctor The current (inner) dimensions of the horn including the printed part down to the AMT membrane are: 530 mm width, 290 mm height, 320 mm depth. The -3 dB point is around 300 Hz with open backs, I thing I should get a lower response when I put the back covers on the mids. I estimate somewhere around 200 Hz crossover point should be possible. 300 Hz is actually good enough for my purpose (with a separate midbass unit below it).
@magic44ken I have only one unit built at the moment. The dispersion in the HF should be 30 degrees, which gives theoretically roughly 175 - 205 cm high window at the distances you specify. I would say that most of the perceived changes in sound would be from the reflections, not from direct sound. But I may be wrong.
@magic44ken I have only one unit built at the moment. The dispersion in the HF should be 30 degrees, which gives theoretically roughly 175 - 205 cm high window at the distances you specify. I would say that most of the perceived changes in sound would be from the reflections, not from direct sound. But I may be wrong.
A little progress. The AMT back cover is finished, the glue needs to dry, damping material will be installed and foam tape for sealing it. The parts are printed on different printers from different materials, that is why they do not align perfectly, one of the printers is not really calibrated for dimensions and prints slightly smaller things.
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I have mixed feelings about the results. The sound is really great, no doubt about that, but it feels all quite impractical and I am not sure if I mind the narow vertical or not. Now I plan to built a large 3way Synergy with a traditional compression driver. And maybe then again one with an AMT - the arrangement around the throat must be done in a better way. Since I always wanted to try a proper open baffle speaker, the AMT will be used with a Deltalite II 15" in a minimal baffle test arrangement.
An AMT synergy is really something special, but I think I need to gather more practical experience to do it correctly next time. I still have an idea or two and I plan to use the GRS planars as test units, since they are easier to mount. Still, I consider the Heil AMT the best sounding HF unit for my ears...So good that I will most probably build a second quick and dirty impractical unit for listening before the large synergy is built.
An AMT synergy is really something special, but I think I need to gather more practical experience to do it correctly next time. I still have an idea or two and I plan to use the GRS planars as test units, since they are easier to mount. Still, I consider the Heil AMT the best sounding HF unit for my ears...So good that I will most probably build a second quick and dirty impractical unit for listening before the large synergy is built.
I was thinking a bit more about this and tried fitting things together in 3D and actually, it will be possible to build a large 3 way MEH with the AMT. Using slightly lower crossover than now, one 4NDF34 firing from the top, and (most probably) a 10CL51 firing from the bottom, both sealed. All this with 90 x 40 pattern and 75 cm internal mouth width, single flare with the option of adding the secondary if needed.