1" : 18Sound XT1086
1.4" :18Sound XT1464
Both are not completely diffraction-free, but about the best of what is commercially available.
If you don't mind some beaming, you might want to look at FaitalPro horns.
This one is also very good and only $13:
1.4" :18Sound XT1464
Both are not completely diffraction-free, but about the best of what is commercially available.
If you don't mind some beaming, you might want to look at FaitalPro horns.
This one is also very good and only $13:
An externally hosted image should be here but it was not working when we last tested it.
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The closest thing to a diffraction-free horn would be docali's spherical horn with a complete
roll-back:
Or 270° roll-back culminating in a bullet shape, similar to this:
roll-back:
Or 270° roll-back culminating in a bullet shape, similar to this:
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Even 'near diffraction free' still needs to be equalised as well as crossed. A waveguide with a bad response will surely sound bad.
Member
Joined 2006
I had the 2380 clones in this Cornscala. I really liked the SQ of the D405 mid driver. Getting back to the 2386:
Wow, DI 10 at 800 Hz and climbing to DI 20 at 20 kHz.
Contrast that to JBL 2384, a 90 x 50 pattern.
I find the JBL 2384 90 x 50 pattern already too narrow and looking for more of a 100 x 100 CD pattern. I can't imagine the narrow beamwidth of a 40 x 20 pattern of the 2386 in a near field living room scenario. The 2386 is a long throw horn designed for stadiums and arenas...
Ro808, I had those QSC clones with a BMS 1" 4540nd that genuinely made it past 20 kHz and sounded like a tweeter instead of a horn. Should have kept them.
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Really interesting dual spider woofer, with one each side of the gap. Fist time i see this kind of arrangement.
The horn in the Strauss is not a 2386. When we look at pictures of the 2386 there is no diffraction slot and the horn is quite deep. The horn on the Strauss has a diffraction slot and isn't very deep.
Regards
Charles
Regards
Charles
I'm pretty sure its the 2382a......we talked about this loudspeaker a while ago about how it has a diffraction slotted horn but its still perceived well, today, even though...
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But that's not just the 2384 is it?
Looks like the whole 4722 - and the dip in vertical beamwidth around 600 Hz is the interaction of the horn with the stacked woofers.
Or so I suspect, I have an idea about how to better optimise this, do you have any data on the 2384 alone?
Best wishes
David
Well I guess this is the dreaded waistbanding. From the pictures on the Speaker Exchange website I would quess the vertical opening to be around 12" which would equal Lambda/2 around 600 Hz.
In the horizontal plane it is less pronounced due to the fact that the vertical (i.e. left and right) edges are less sharp and the width is not constant over the whole height (PT waveguide). But there is still a slight depression a little lower in the diagram, although nothing to worry about.
Regards
Charles
In the horizontal plane it is less pronounced due to the fact that the vertical (i.e. left and right) edges are less sharp and the width is not constant over the whole height (PT waveguide). But there is still a slight depression a little lower in the diagram, although nothing to worry about.
Regards
Charles
Hi Charles
Yes, horns can waistband but I suspect here the problem is made worse by the vertically stacked woofers in the 4722.
That is what I would like to confirm with Mitch.
He has a 2384 and I hope he has data for the horn alone.
You mean the small dip at 400 Hz?
This is below crossover so I think not horn related, maybe some minor contribution.
I think the lack of a waistband in the horizontal plane shows that with careful mouth transition there is minimal problem.
Hence my suspicion that the vertical waistband is, at least in part, woofer interaction.
But you are correct, the smaller available roundover in the vertical plane would increases the horn contribution.
Best wishes
David
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The horn used in the Strauss SE-MF-2 and 2.1 is the JBL 2380A, 90x40° Flat front Bi-radial horn.
An externally hosted image should be here but it was not working when we last tested it.
The 2382A is 120x40°, which is visible in the widening of horizontal mouth 'walls', a shallower mouth overall and subsequently a longer slot > a narrower angle results in a deeper mouth. For this reason, in the 2386A the diffraction slot is almost gone. In docali's Selenium - a modified 2386A - there's no diffraction slot at all.
An externally hosted image should be here but it was not working when we last tested it.
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Hi Mitch,
40 x 20 is certainly a problem in any system, but 100 x 100 is wider than I think optimal, even in a small room. I would love to be able to use a narrower 70 x 70 device, but there isn't a feasible woofer that can do that except at >> 1 kHz. Hence 90 x 90 seems to be the highest DI that I found feasible to build cost effectively.
Member
Joined 2006