@helomech wrote:
The disadvantage to many ribbon and AMT tweeters is narrow bandwidth and/or wonky vertical dispersion. That, and they can be very fragile (especially ribbons). I agree that SOME AMTs and Ribbons can be superior to a beryllium dome, IF they are very good ones, such as those from RAAL or Mundorf. Regarding planar tweeters, I don’t find that to be the case. They can sound smoother than a hard dome, but I’ve yet to encounter one that can match a beryllium or diamond dome in air and detail, including the Børresen tweeters, which are based on the old Philips design. The expensive Børresen models do get close to a RAAL, but in a quick succession A/B it can be substantially apparent that the RAALs offer greater resolution.
Most direct radiating dome tweeters don’t go below 2kHz comfortably, and thus dictate 3-way+ designs (with all that entails) for a physically more capably package. Another aspect is poor power response at their crossover unless loaded with a large enough waveguide. A third aspect is their sound; very generally I just don’t warm to the sound of direct radiating dome tweeters, and when less conspicuous in the mix the better - indeed rather that (think Harbeth) and loose some "air and detail" than aiming for the latter. Waveguide loading can help, but compared to other driver designs dome tweeters still lack dynamics and transient "snap."
As for beryllium dome tweeters it doesn’t change the fundamental aspect of a dome tweeter sound, to my mind. They sound good in the Grimm’s, but there’s a whole design aspect beyond that that co-contributes to the qualities here, and yet they are still dynamically limited. The Mundorf AMT’s I’ve heard (the larger, most efficient iteration) don’t come across as more resolving than the planar magnetic driver in my speakers, don’t go as low (at least not down to 1kHz with short-horn loading), and actually I find them to have a bit more "character," but I’m sure to some that may come across as more detailed. I have limited experience with the RAAL’s, but indications are they’re great.
Narrow vertical dispersion is mostly a good thing in my book, and you don’t find dome tweeters that cover between 500-1kHz to 20kHz, not least with higher efficiency. Planar magnetic drivers on the other hand can do that (short-horn loaded), AMT’s can (horn loaded also), as well as compression drivers.
A lot of this no doubt comes down to preference and how we value or ascribe impressions to what they really mean or refer to. The really resolving "and well-behaved" (meaning: low smear, transient prowess) MF/HF drivers to my ears are smoother and less "impressive" at first glance, but upon closer inspection it becomes clear they’re really more natural sounding and devoid of artefacts.
Speakers employing the best hard domes or ribbons don’t typically need a super tweeter IMO. Super tweeters tend to be most effective when augmenting mediocre soft/hard domes.
I had the context of large format horns/compression drivers in mind here, and where super tweeters can be a necessity.
I generally don’t care much for soft domes, but since you brought up bandwidth, I figure it’s worth mentioning this particular tweeter which gets close to beryllium in subjective performance but is also wide bandwidth:
https://www.madisoundspeakerstore.com/seas-soft-dome-tweeters/seas-excel-t35c-002-35mm-mid-tweeter/
That’s more like it, and fairly good sensitivity.
Regarding woofers, I believe ATC’s are not quite as low in distortion as Purifi and the likes of Scanspeak Illuminator or SB Satori. Subjectively, I like the active ATCs but they are too expensive IMO, considering one can build a passive speaker that’s as good or nearly as good for much less coin.
Considering what’s included in the package I don’t find active ATC’s to be too expensive, comparatively speaking, and if looks don’t matter go for the PRO models; they sound the same as their domestic sibling models while saving you a lot of dough.
ATC’s underhung SL woofers are seriously capable and clean sounding, not least actively configured. I doubt Purifi, Scanspeak or other can make a meaningful difference for the better sonically compared to the ATC’s, but who am I to say. Whatever people prefer here may come down to other aspects than what’s really about distortion levels.
As for horns, I generally find them shouty, almost regardless of model. The one notable exception is the JBL 4367. I don’t like how they image in most cases either.
Funny, to my ears the 4367’s come across as rather "splashy" in the horn section. Impressive and very lively at first, but at more lengthy audition I tire of them - they’re just "too much." String instruments really show their limitations, I find.
Yes, horns are a mixed bag. The better of them are not really shouty to me as they’re direct in their presentation (i.e.: more direct vs. reflected sound), and I know this turns some people off. JMLC horns can sound great. Tractrix designs as well, and also conical variants.
Or take a pair of active Meyer Sound speakers like the X-10’s or Acheron cinema series model 80/100 - seriously, they blow away any domestic JBL’s and most other "hifi" horn stuff, but you wouldn’t believe from their pro origins. Same goes for my active SA speakers with their horn-loaded planar magnetic drivers.
