The up-to-date data - for Alu dome height is 6.85 mm +/-0.15mm, and 4.45 mm +/-0.15mm for Be version
Pretty tall for a metal dome. Thanks!
The up-to-date data - for Alu dome height is 6.85 mm +/-0.15mm, and 4.45 mm +/-0.15mm for Be version
Could you also measure the distance of the mounting holes from center and hole size? I'll use this to make two pins on the waveguide to locate the tweeter accurately and without fear of accidentally crushing the surround.
I'm fully agree with you. Somewhere in a closet the D2430K+M2wg combo is still waiting for my hands
If Klaus Heinz would make his AMT tweeter available (not gonna happen) i think that would be in line with mentioned above.
You have to give up either vertical or horizontal dispersion to get enough surface area. When you have a square, you have the worst of both worlds.
Up until now there has been no tech to allow a true ribbon mid, which is what might dictate a square diaphragm.
IF you are really looking for a tweeter used above say 3Khz, then you can make a true ribbon sort of "square", that can compete with say a 1 inch dome tweeter. in terms of dispersion anyway.
Point Source – Raven Design Studio
https://ravendesignstudio.com/wp-content/uploads/2017/11/RavenPointSource.pdf
Is this what you mean? Im not exactly sure what your asking.
There are "planer" types that can be made in about any size "square". These can be quite good However their horizontal dispersion is not all that good.
https://www.parts-express.com/pedocs/specs/264-714-bohlender-graebener-specifications-44576.pdf
A true free swinging ribbon can be made square and much larger than the Raven shown above, However the magnet structure needed to energize across the large gaps will be absolutely huge, heavy, and very expensive. Even then you will have trouble making a "ribbon" that behaves well thats more than about 2-3 inches wide
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The Raven would be what I am thinking about - Increase the area so that you hit the 1.8kHz which SRT-7 hits and the vertical dispersion could - potentially - improve or be more similar to the horizontal dispersion.
Or make a super tweeter and a upper midrange - 4-way system perhaps.
I'm thinking out loud here
Or make a super tweeter and a upper midrange - 4-way system perhaps.
I'm thinking out loud here
Ok well...
Increasing area in such design means making them longer. You simply cannot increase width significantly in a practical way.
The Ravens are made from a very thin foil. The reason this is important is that the super thin foil constructions simply cannot put up with the stress of going below 2 kHz in a smallish ribbon ( meaning a short one that still has reasonable vertical dispersion). If ya want to goto say 1.8 Khz with the super thin foil designs you will be into a ribbon at least 6 inches tall, AND you will need to use steep filters to keep it from shredding itself.
RAAL: 70-20XR
Here is a smallish design from RAAL that they claim will do your 1.8 cross point, BUT again it will need a steep filter AND only avail to manufactures. Also they are being mysterious about keeping the construction a secret. My red flags are up with this. I suspect its basically a thicker foil than they use in their other designs ( which BTW use a very thin foil like the ravens), and this allows a lower cross point with a smallish ribbon.
The SRT-7 is not really a true free swinging ribbon, it has a sort of half roll suspension along the sides of the diaphragm. They appear to have executed this method well. This and a thicker foil than the Ravens and RAALs use are the reason their smallish "ribbon" can stay alive at a lower crossover point.
BTW my own development work tells me that so long as the ribbon is about 3 inches long or less, then the vert dispersion is not a problem for a seated listener. I dont do critical listening when Im walking around and the 3 inch ribbon still sounds very good when im moving around.
Is there a reason you insist on getting equill horz and vert dispersion?
Increasing area in such design means making them longer. You simply cannot increase width significantly in a practical way.
The Ravens are made from a very thin foil. The reason this is important is that the super thin foil constructions simply cannot put up with the stress of going below 2 kHz in a smallish ribbon ( meaning a short one that still has reasonable vertical dispersion). If ya want to goto say 1.8 Khz with the super thin foil designs you will be into a ribbon at least 6 inches tall, AND you will need to use steep filters to keep it from shredding itself.
RAAL: 70-20XR
Here is a smallish design from RAAL that they claim will do your 1.8 cross point, BUT again it will need a steep filter AND only avail to manufactures. Also they are being mysterious about keeping the construction a secret. My red flags are up with this. I suspect its basically a thicker foil than they use in their other designs ( which BTW use a very thin foil like the ravens), and this allows a lower cross point with a smallish ribbon.
The SRT-7 is not really a true free swinging ribbon, it has a sort of half roll suspension along the sides of the diaphragm. They appear to have executed this method well. This and a thicker foil than the Ravens and RAALs use are the reason their smallish "ribbon" can stay alive at a lower crossover point.
BTW my own development work tells me that so long as the ribbon is about 3 inches long or less, then the vert dispersion is not a problem for a seated listener. I dont do critical listening when Im walking around and the 3 inch ribbon still sounds very good when im moving around.
Is there a reason you insist on getting equill horz and vert dispersion?
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^
If we compare SRT-7 to BlieSMa T25B-6, the T25B-6 has a better dispersion due to its hemispherical shape, so vertical and horizontal product is the same.
I am not disappointed by the SRT-7 vertical off-axis behavior, it is actually better than many bellowed dome tweeters, but we can see that at ca 16-17kHz and 60 degree, it losses more or less all of its energy. In reality, this will probably not be a problem.
I am being extremely picky here - the listening window will more than likely be very good.
(The listening window curve is an average of horizontal responses at +/- 10, 20, and 30 degrees on the horizontal axis, and +/- 10 degrees on the vertical axis - ANSI/CTA-2034-A).
Optimizing a loudspeaker for the ANSI/CTA-2034-A or "Spin-O-Rama" measurement or performance demand quite a lot of the engineer and components used.
To end on a good note, both the SRT-7 and T25 series tweeters are pushing the limits of what can be done and both Dmitry and Stanislav are master engineers.
If we compare SRT-7 to BlieSMa T25B-6, the T25B-6 has a better dispersion due to its hemispherical shape, so vertical and horizontal product is the same.
I am not disappointed by the SRT-7 vertical off-axis behavior, it is actually better than many bellowed dome tweeters, but we can see that at ca 16-17kHz and 60 degree, it losses more or less all of its energy. In reality, this will probably not be a problem.
I am being extremely picky here
- the listening window will more than likely be very good.(The listening window curve is an average of horizontal responses at +/- 10, 20, and 30 degrees on the horizontal axis, and +/- 10 degrees on the vertical axis - ANSI/CTA-2034-A).
Optimizing a loudspeaker for the ANSI/CTA-2034-A or "Spin-O-Rama" measurement or performance demand quite a lot of the engineer and components used.
To end on a good note, both the SRT-7 and T25 series tweeters are pushing the limits of what can be done and both Dmitry and Stanislav are master engineers.
^
If we compare SRT-7 to BlieSMa T25B-6, the T25B-6 has a better dispersion due to its hemispherical shape, so vertical and horizontal product is the same.
The shape is little to do with it, its the size
I am not disappointed by the SRT-7 vertical off-axis behavior, it is actually better than many bellowed dome tweeters, but we can see that at ca 16-17kHz and 60 degree, it losses more or less all of its energy. In reality, this will probably not be a problem.
I agree, in reality it will be little to no problem
I am being extremely picky here
(The listening window curve is an average of horizontal responses at +/- 10, 20, and 30 degrees on the horizontal axis, and +/- 10 degrees on the vertical axis - ANSI/CTA-2034-A).
Optimizing a loudspeaker for the ANSI/CTA-2034-A or "Spin-O-Rama" measurement or performance demand quite a lot of the engineer and components used.
To end on a good note, both the SRT-7 and T25 series tweeters are pushing the limits of what can be done and both Dmitry and Stanislav are master engineers.
Im sure they are, however the SRT-7 is not pushing the limit in my experience. The dome I cannot comment on.