Anyone consider a slight horn loading of the Neo10 to support the rising response down low? Seems like a near perfect application for a simple DIY flare vertically. Just a thought.
Yes, but I haven't come up with anything which I like. One of the problems with the Neo10 is its radiating surface is roughly a full wavelength long at 1.5kHz, so even if you have modest SPL requirements and can push the Neo3 cross down low (I'm auditioning a 1.6kHz LR6 cross as I type this) the increase in separation between the drivers in a traditional vertical layout caused by a typical horn is pretty unattractive. There are ways around this, but mostly they seem to involve narrowing horizontal directivity to match and the baffle shapes start to get rather complex. An alternate, if unconventional, approach which might work is to hang the Neo3 alongside the Neo10. It's on my list of things to experiment with, but haven't got there yet.
A simpler alternative is to attach baffles to the sides of the Neo10 to move its dipole peak lower. For example, the dipole peak drops from 1.8kHz nude to 1kHz if it's extended to 20cm wide, providing 2.5dB of gain at 300Hz. Wouldn't surprise me if you could do a bit better than that and still get good horizontal directivity by moving in the direction of a dipole waveguide. The same idea seems like it ought to work with Neo3s, albeit on a smaller scale, but it's not something I'll have a chance to try for a bit.
A simpler alternative is to attach baffles to the sides of the Neo10 to move its dipole peak lower. For example, the dipole peak drops from 1.8kHz nude to 1kHz if it's extended to 20cm wide, providing 2.5dB of gain at 300Hz. Wouldn't surprise me if you could do a bit better than that and still get good horizontal directivity by moving in the direction of a dipole waveguide. The same idea seems like it ought to work with Neo3s, albeit on a smaller scale, but it's not something I'll have a chance to try for a bit.
Twest820,
your idea is to decrease the frequency of the first dipole peak to about 1 khz and to cross at 1.6 khz? I see (like you) some disadvantages to using a Neo10 in a dipole. Just to keep things in perspective, even the Visaton AL170 is perfectly symmetrical up to 1 khz. So what are you gaining and what do you have to trade in?
your idea is to decrease the frequency of the first dipole peak to about 1 khz and to cross at 1.6 khz? I see (like you) some disadvantages to using a Neo10 in a dipole. Just to keep things in perspective, even the Visaton AL170 is perfectly symmetrical up to 1 khz. So what are you gaining and what do you have to trade in?
Perfectly symmetrical about which axis? I've not measured a lot of woofers but while the few I have measured exhibit reasonable front to back symmetry below the dipole peak there's up to 5dB of mismatch around certain frequencies at certain angles. The Neo10 offers better front to back at the expense of more difficult vertical matching, though my guess is the net difference between and a woofer would be relatively minor. In a typical listening configuration the surface area illuminated for reflections decreases the farther off the horizontal plane one gets. So, arguably, moving directivity mismatches towards the vertical should tend to make them less noticeable. It should also help the mismatches are off axis and hence at lower SPL than on axis front/rear mismatches. Since there's not a strong pivot here it probably comes down to the details of driver selection, room acoustics, and subjective preferences, particularly listening level.
I'm not too interested in flat baffle extension of the Neo10, though from a directivity standpoint there might be some advantage to widening the Neo10 to match the aspect ratio of the Neo3. Lots of options to investigate in that space. I would also point out crossing to an eight inch woofer, most of which have a dipole peak around 1.3kHz, is probably competitive in this regard as well. Personally, a fair amount of my motivation to look at the Neo10 is a preference for the sound of magnetostats to that of cones. I'm somewhat fussy about woofer selection and my list of cone alternatives to the Neo10 is quite short.
I'm not too interested in flat baffle extension of the Neo10, though from a directivity standpoint there might be some advantage to widening the Neo10 to match the aspect ratio of the Neo3. Lots of options to investigate in that space. I would also point out crossing to an eight inch woofer, most of which have a dipole peak around 1.3kHz, is probably competitive in this regard as well. Personally, a fair amount of my motivation to look at the Neo10 is a preference for the sound of magnetostats to that of cones. I'm somewhat fussy about woofer selection and my list of cone alternatives to the Neo10 is quite short.
Todd,
I wish you all luck going forward to test Neo10, it will interest a lot of people I think. Going with the 8S, I think, begs a 4-way solution.
Funny, but my first option with the Neo10 would have been a 20 cm wide baffle. Neo10 right at the top and Neo3 nude above it. My first crossover choice would be 2 - 2.5 kHz very sharp.
It will be interesting to see how much EQ Neo10 will need and how it then performs.
/Erling
I wish you all luck going forward to test Neo10, it will interest a lot of people I think. Going with the 8S, I think, begs a 4-way solution.
Funny, but my first option with the Neo10 would have been a 20 cm wide baffle. Neo10 right at the top and Neo3 nude above it. My first crossover choice would be 2 - 2.5 kHz very sharp.
It will be interesting to see how much EQ Neo10 will need and how it then performs.
/Erling
The Neo10 datasheet provides the free air SPL, which conveniently happens to be the nude dipole case. So the magnitude EQ requirements are easily determined. Haven't seen any phase data, but that's not usually too hard to get mostly right in Arbitrator. Hobby Hifi's and Zaph's distortion data is in good agreement so there's a pretty good picture of how the driver would operate at 200Hz in the 85-90dB range, which also conveniently happens to match the free air SPL, so I'd expect a 250-300Hz LR6 cross to be viable at my modest SPL requirements. Maybe 200Hz. Personally I wouldn't want to cross above the vertical null at 1.8kHz or lower order than LR6, but you've a considerably higher tolerance than I for that.
I was originally planning a Neo8 four way before the 8S and 10 became availability. The 8's a frustrating driver to work with, as you can really only get the 1-2kHz range out of it and even then it's not so great at 1kHz. That started me looking at cone mids, which led back to three ways, at which point Zaph's Neo10 data was out. I would hope the 8S would work well as a filler driver between a Neo3 and a nude 12 or 15 around the 800Hz or 650Hz dipole peak. If it has a bit more reach crossing to a nude 18 at 500Hz might be an option. All three are viable three ways with good options available for woofers to mate the planars to, though they're all stronger when made four way with closed box subs underneath. Crossing a Neo10 to an 18 should yield somewhat better performance due to the narrower bandwidth affected by bass excursions, reduced acoustic size, and the option of using a baffle on the 18.
I was originally planning a Neo8 four way before the 8S and 10 became availability. The 8's a frustrating driver to work with, as you can really only get the 1-2kHz range out of it and even then it's not so great at 1kHz. That started me looking at cone mids, which led back to three ways, at which point Zaph's Neo10 data was out. I would hope the 8S would work well as a filler driver between a Neo3 and a nude 12 or 15 around the 800Hz or 650Hz dipole peak. If it has a bit more reach crossing to a nude 18 at 500Hz might be an option. All three are viable three ways with good options available for woofers to mate the planars to, though they're all stronger when made four way with closed box subs underneath. Crossing a Neo10 to an 18 should yield somewhat better performance due to the narrower bandwidth affected by bass excursions, reduced acoustic size, and the option of using a baffle on the 18.
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