from a long time in my crazy mind there is the question:
- what are the advantages and disadvantages of ring dome tweeters vs dome ?
exactly i'm refering to sbacoustics tweeters:
- ring :
SATORI TW29RN :: SB Acoustics
- dome :
SB Acoustics :: SATORI TW29DN
- what are the advantages and disadvantages of ring dome tweeters vs dome ?
exactly i'm refering to sbacoustics tweeters:
- ring :
SATORI TW29RN :: SB Acoustics
- dome :
SB Acoustics :: SATORI TW29DN
Having lived with Satori beryllium and beryllium compression drivers for a while, all home audio silk domes now sound slightly uncontrolled and has this flappy fabric distortion.
Not with the Satori TW29 and I assume, all other ring radiators. It remain controlled enough for my liking.
So TW29DN and all other high end silk domes will have this distortion I mentioned but most likely will be interpreted as a nice shimmer up top to most.
Not with the Satori TW29 and I assume, all other ring radiators. It remain controlled enough for my liking.
So TW29DN and all other high end silk domes will have this distortion I mentioned but most likely will be interpreted as a nice shimmer up top to most.
A dome has more piston area, so it can either be used to a lower frequency or play low frequencies with less distortion.
A ring radiator has its dome fixed at the enter, so it can resonate in less modes. Cone breakup in soft domes starts at several kHz, though the breakup is well damped.
High frequency dispersion can differ, which should be evaluated case by case. This is difficult to predict as without knowledge of the dome, because the dome isn't pistonic at those frequencies any more. (This applies to soft domes only, hard domes are pistonic up to their first breakup slightly above 20 kHz)
A ring radiator has its dome fixed at the enter, so it can resonate in less modes. Cone breakup in soft domes starts at several kHz, though the breakup is well damped.
High frequency dispersion can differ, which should be evaluated case by case. This is difficult to predict as without knowledge of the dome, because the dome isn't pistonic at those frequencies any more. (This applies to soft domes only, hard domes are pistonic up to their first breakup slightly above 20 kHz)
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Are you guys sure, that this Satori dimple dome is a real ring radiator? Has someone opened it ?
The dimple makes it more rigid than a hemispherical dome and increases pistonic (flat) area. We can see the difference in off-axis responses vs. on-axis. Both show minimal cone resonances, hardly any.
The dimple makes it more rigid than a hemispherical dome and increases pistonic (flat) area. We can see the difference in off-axis responses vs. on-axis. Both show minimal cone resonances, hardly any.
It is being sold and tested as a ring radiator and it has got a dimple, that's all we know. Putting a dimple in a soft dome doesn't make sense, but who knows. Adding a dimple to a dome increases area, but does not increase effective area because motion is not perpendicular to the surface at the dimple.
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On the SB29 the dimple is fixed to a solid mounting post in the middle (verified by gently pressing it with my finger
). I assume the TW29 is no different, so yes it is a 'real' ring radiator and not just a dome with an unsupported dimple.
You know, it may be worth to examine the closely related XT25 and DA25 series from Peerless.
The XT25 has a narrower dispersion, which for me often works best. I use it in a HT for center and surround duties, with the mains using big AMTs. They do not get embarrassed. I have no experience with their dome counterparts though.
As I read, the ring radiator was originally done as a joke. A designer stuck a thumb tack in the middle of the dome and it actually sounded better. Looking at the XT25 for an example, it has very flat extension way past 20 kHz without any oil-can resonance. So that alone is a very good reason to consider this relatively inexpensive driver, or the Scanspeak equivalent.
The XT25 has a narrower dispersion, which for me often works best. I use it in a HT for center and surround duties, with the mains using big AMTs. They do not get embarrassed. I have no experience with their dome counterparts though.
As I read, the ring radiator was originally done as a joke. A designer stuck a thumb tack in the middle of the dome and it actually sounded better. Looking at the XT25 for an example, it has very flat extension way past 20 kHz without any oil-can resonance. So that alone is a very good reason to consider this relatively inexpensive driver, or the Scanspeak equivalent.
Hello,
I have 29RDC, 21RDC and I heard 19XT and 25XT.
The crossover for 21RDC will be ready in the next week, but it is a dissappointment in the first hearing
The distorsion below 3k is high.
The XT's were narrow transmission.
29RDC is good, but there are better tweeters it the market - of course for higher price.
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PS: we measured both 29RDC and Satori in the Hungarian forum, the difference is minimal. The aluminium faceplate don't worth the 2,5* price.
I have 29RDC, 21RDC and I heard 19XT and 25XT.
The crossover for 21RDC will be ready in the next week, but it is a dissappointment in the first hearing
The distorsion below 3k is high.
The XT's were narrow transmission.
29RDC is good, but there are better tweeters it the market - of course for higher price.
-------------
PS: we measured both 29RDC and Satori in the Hungarian forum, the difference is minimal. The aluminium faceplate don't worth the 2,5* price.
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The TW29RN does not have a replaceable voice coil assembly unlike domes, whole tweeter needs to be replaced in case of blowout (and forms a source for pictures like this) or manually reconed. I think this is true of all ring radiator tweeters, as the center of the dome is fixed to the 'stator', and the VC assembly is actually the 'rotor'.
Do you want bandwidth or high frequency extension? It basically comes down to that. A dome will have more displacement and low frequency extension (because a circle has a larger area than a ring.) It's pretty trivial to get a ring to play past 20khz because the diaphragm is nearly flat.
You can also get a dome to behave more like a ring, by masking off the tip of the dome.
Long story short: the best option will depend on what you're building. Do you need a low xover point? If so, use a dome.
No, Allison tweeter is opposite to ring radiator. A small voice coil driving small dome and big outer "skirt".
The SB ring-domes are not direct derivations from the XT25, given that they have a different hybrid dome design, different baskets / frames, motor &c. The principle is similar; IIRC they didn't use the extended central plug because that was the bit that was patented & remained in force (I haven't time to check to see if it still is).
It's worth noting the SB ring-domes like the TW29R actually have more, not less, radiating surface than a conventional 1in dome tweeter, and something like 70% more than the XT25, which purely in terms of Sd is more akin to a 3/4in dome. The central pinning does prevent the out-of-phase resonance that a soft-dome tweeter can experience; the tradeoff is that the entire diaphragm, like other ring-radiators e.g. the XT25, is effectively part of the suspension, and from a philosophical POV some point out that is nominally the least-linear component in a conventional dome assembly. YMMV. The ring-radiators appear to have driven or helped drive the fashion for large surrounds with a smaller central dome as seen in many of Scan's Discovery / Illuminator / Revelator units, and some Seas models, the surround forming a significant part of the OA radiating surface. The same general criticism could be levelled at those as the pure ring radiators or ring domes with the pinned centre (which is not to say it's a problem in practice, just a critique that can be levelled viewed from one engineering perspective). It's interesting to note that this practice chimes with the shift in distortion behaviour of many modern units, with elevated levels of HD2 on the bottom end (separate from the inevitable rise in units with greater nominal flat LF BW) & reduced levels of higher harmonics, compared to older practice where slightly higher levels of HD were often accepted across the range, with less of a rise in HD2 low down.
The ferrite & neo motor ring-dome Satori models are my favourite 'soft' tweeters, although I quite like Scan's 7100 & still have a soft spot for Seas's Millennium. SB appear to have a range of 'conventional' soft dome versions of the Satori in the works also; not entirely certain why they'd bother given the excellent performance of the existing ring-domes but I suppose it gives them an addition to the range while retaining a large amount of part commonality.
It's worth noting the SB ring-domes like the TW29R actually have more, not less, radiating surface than a conventional 1in dome tweeter, and something like 70% more than the XT25, which purely in terms of Sd is more akin to a 3/4in dome. The central pinning does prevent the out-of-phase resonance that a soft-dome tweeter can experience; the tradeoff is that the entire diaphragm, like other ring-radiators e.g. the XT25, is effectively part of the suspension, and from a philosophical POV some point out that is nominally the least-linear component in a conventional dome assembly. YMMV. The ring-radiators appear to have driven or helped drive the fashion for large surrounds with a smaller central dome as seen in many of Scan's Discovery / Illuminator / Revelator units, and some Seas models, the surround forming a significant part of the OA radiating surface. The same general criticism could be levelled at those as the pure ring radiators or ring domes with the pinned centre (which is not to say it's a problem in practice, just a critique that can be levelled viewed from one engineering perspective). It's interesting to note that this practice chimes with the shift in distortion behaviour of many modern units, with elevated levels of HD2 on the bottom end (separate from the inevitable rise in units with greater nominal flat LF BW) & reduced levels of higher harmonics, compared to older practice where slightly higher levels of HD were often accepted across the range, with less of a rise in HD2 low down.
The ferrite & neo motor ring-dome Satori models are my favourite 'soft' tweeters, although I quite like Scan's 7100 & still have a soft spot for Seas's Millennium. SB appear to have a range of 'conventional' soft dome versions of the Satori in the works also; not entirely certain why they'd bother given the excellent performance of the existing ring-domes but I suppose it gives them an addition to the range while retaining a large amount of part commonality.
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