Sure. Not got around to physical testing yet.
Two parts? Just the thickness/stock issue. Baffle = 50mm. Throat addon positioned with the two 8mm pin holes you can see. Fits together perfectly and will probably glue in place later.
The addon = 73mm deep. Aiming for acoustic alignment of woofer and cd after a few design interations.
We’ll see.
I’ve put dowel pin holes on the back of the baffle so I can throw on some resin and recut throat shape if required.
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No sanding. Just poor quality fluffy MDF. I used a 6mm ballnose over the surface.
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With a smooth throat to rectangular transistion (without OS contour), one could obtain decent polars. Still, Marcel's ATH is obviously better.
These are 15 year old examples from a respected German horn manufacturer.
(BTW, he didn't use the textured material for cosmetic reasons)
These are 15 year old examples from a respected German horn manufacturer.
(BTW, he didn't use the textured material for cosmetic reasons
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You did take the HF146's 29° exit angle into account, I presume?
Looking forward to your measurements.
It is not so often that someone uses an 1.4" exit driver with an OS waveguide.
Indeed, if you look at the above section you can see the HF146(grey) mating with the throat (green).
What are the main issues with 1.4 cd and OS?
I could machine in a texture at high speed. Also thought about covering the baffle/horn in a textured synthetic leather.
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Nothing in particular, but I believe an 1" entrance OSWG does the "pulling-out-of-the-wavefront-trick" somewhat better.
That is: up to 20k instead of ca. 15k, but this may depend on the phaseplug and the length of the driver's conical exit section as well
Perhaps Dr. Geddes could respond to this.
That is: up to 20k instead of ca. 15k, but this may depend on the phaseplug and the length of the driver's conical exit section as well
Perhaps Dr. Geddes could respond to this.
Preparing sim charts now. I can always switch over to a HF10AK if need arises.
Catching up on older posts....
Geddes on Waveguides
Catching up on older posts....
Geddes on Waveguides
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The HF10AK is a very nice 1" driver, a true substitute for the TAD TD-2001 (at a fraction of the price), but it's probably better suited to classic Salmon-type of horns. It's a first generation 1" FaitalPro driver with a deeper conical section, designed to work with Faital's own elliptical Tractrix horns.
That's not to say it won't work behind a OSWG, but in general "pancake style" drivers - like the HF108R - tend to perform better with modern, shallow waveguides.
That's not to say it won't work behind a OSWG, but in general "pancake style" drivers - like the HF108R - tend to perform better with modern, shallow waveguides.
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I've made and measured OS waveguides in 2" throats. Exactly what one would expect with acoustics, as the dimensions get larger HF effects begin lower. Based on the results, it seemed to me that it would not be possible to get as clean a control above 10kHz with 2" as it is with 1", but maybe some of that was the driver as the 4" diaphragms have known issues about 10 kHz. 1" was all I ever needed power wise and I don't buy the "lower is better" crossover ideas that seem to abound.
1", 1.4", 2" they will all do the same things just at different frequencies. The "pull-out" will happen in them all and about the same in % terms, just at different frequencies. At these frequencies, however, I would expect enormous variance with the driver.
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That’s good, right? 86x53 design. Vertical and diagonal very similar. Took quite a few iterations to get it as smooth as that over 61 simulated bands no smoothing.
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Don't attach too much importance to my theoretical arguments.
In practice it's highly unlikely you'll notice the difference between (measured) 85% vs 100% of the simulated WG performance.
IOW minor deviations from perfection are nothing to worry about.
WRT a CD + 8" woofer + 10" radiator, I believe mabat has worked on a similar concept, albeit with larger drivers.
In practice it's highly unlikely you'll notice the difference between (measured) 85% vs 100% of the simulated WG performance.
IOW minor deviations from perfection are nothing to worry about.
WRT a CD + 8" woofer + 10" radiator, I believe mabat has worked on a similar concept, albeit with larger drivers.
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Extended the range out to 20K, no smoothing. Bit bumpy 12K upwards on axis but appears to smooth a little 20deg to 40deg off axis.
Actually, looking at my config, final design ended up as 87 x 53 x 120mm.
LineSource - "Measurements for the Beyma 12P80Nd_v2 from the AVSforum show -6db SPL around +/- 40 degree polar response ... "
Actually, looking at my config, final design ended up as 87 x 53 x 120mm.
LineSource - "Measurements for the Beyma 12P80Nd_v2 from the AVSforum show -6db SPL around +/- 40 degree polar response ... "
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