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In the Forum: Horn-Loaded Speakers
In the Thread: The Kato-san's Goto system
Post Subject: Size might be an issuePosted by martinshorn on: 5/24/2017
hi Romy! Good thought with the current on the damping...
I had another thought. High excusion might create lots of distortion in a compression chamber. No surprise.
But in my oppinion the sizes are often not in proportion. Lets calculate...
If the membrane radius doubles each octave we go lower, the excursion can remain small.
Respectively all other values should remain the same. Including perception of quality.
No one would run a 1 inch driver down to 500Hz but huge excursion... by driver i mean membrane, throat of course half then.
In the system i plan, i want to do it proportionally. And also follow some nice thoughts of the Vox Olympian. It reduces stress by running drivers with high crossover. It should look linear like:
10k XO 1 inch membrane
3k XO 2 inch
1k XO 4 inch
So far all JBL Alnico compression drivers. Now how to continue?
Well down to 300 i have to double again. 8 inch then. No compression drivers in that size. The closest imho would be the Lowther pm4a with its monster alnico. We have to develop our own Phaseplug to make it a compression chamber. I plan to use an 30 inch horn then.
Next step is down to 100 cycles. Doubling linear means a 15 inch driver. In Horn. Could be a Klipsch Corner. Only thing missing is a proper compression and Phaseplug which i have to build first.
Then the last octaves would require double. But as the horn wont fit into regular real estate, we loose 12dB or more. So 4 times again. Which means 8 times in total. Would result in 120 inch. Ok doesn't exist for good reasons.
So we can only use closed cabine with multiple drivers.
Taking 15 inch as an example would mean 8 times 15 inch per channel. Keeping same excursion.
Or 16 times 12 inch.
Or 32 timws 8 inch 
Of course running so many in parallel causes a massiv drop in resistance and still not the same efficiency, so we need more amps.
But as we grow linear, we keep excursion low. That means short coil. Lighter mass, stronger magnet (as we will use multiple engines).
I think that should work well.
Cheers
Josh Rerurn to Romy the Cat's Site