Here are my bitches with the most popular tweeter types:
Metal domes have resonant frequencies around 25-30 Khz. One can argue that
this is above the limits of human hearing, but the resonant spike is so strong
(sometimes 10-20 dB) that I'd think that when excited it throws off the tweeter's
ability to smoothly render the audible frequencies.
Textile domes are smoother, but are often not as fast, let alone rigid, as metal
domes, and most of them roll off quickly above 10 Khz.
Ribbon tweeters are usually very fast and linear to 30Khz or more, but must be
crossed over at 3Khz or higher, which can cause a dispersion suckout around the
crossover point unless a midrange is used or the mid/woofer is 4"
diameter or less.
On the other hand:
Ring radiators don't have a resonant spike and are reasonably linear out to
around 30Khz. It's the tweeter of choice in many Sonus Faber and other high end
speaker companies.
Now, however, there is an emerging tweeter type based on a textile dome
wherein the tip of the dome is "pinned" in place. This converts the
tweeter from a traditional dome tweeter to a ring radiator. I first saw it on
Internet-Direct speaker vendor Aperion's website in their top href=http://lghttp.12393.nexcesscdn.net/805C8C/cdndirectory/media/catalog/
product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/p/r/product-
1194.jpg>Verus line, but I see where Sonus Faber has implemented a very
similar thing in their new href=http://hifilounge.co.uk/image/cache/data/sonusfaber/Olympica%20II/fea4
5bd9-7d1b-4cca-023a-0497ef7e7864-399x325.jpg>Olympica line. Such
a tweeter would be less susceptible to overshoot and beaming, and SF claims
such a tweeter can handle a lower crossover point than for the same tweeter
without the pin.
I thought this tweeter type was a clever concept when I first saw it on the
Aperion, but the Sonus Faber version sort of validates the concept for me. The
grand-bookshelf-loudspeaker-measurements>Stereophile review
measurements show the Aperion tweeter to peak by 5 dB at 10Khz, drop 5
db by 20 Khz, and then rise 5 dB again to 30 Khz, more like a Vifa ring radiator.
Similarly, Sonus Faber claims response out to 30 Khz in its Olympica line.
That said, my current favorite tweeter is the quasi-ribbon in my new
Magneplanar 1.7s. Fast, smooth, extended, good dispersion, and nary a hint of
beaming, overshoot, noticeable dips or peaks, or ringing.
Metal domes have resonant frequencies around 25-30 Khz. One can argue that
this is above the limits of human hearing, but the resonant spike is so strong
(sometimes 10-20 dB) that I'd think that when excited it throws off the tweeter's
ability to smoothly render the audible frequencies.
Textile domes are smoother, but are often not as fast, let alone rigid, as metal
domes, and most of them roll off quickly above 10 Khz.
Ribbon tweeters are usually very fast and linear to 30Khz or more, but must be
crossed over at 3Khz or higher, which can cause a dispersion suckout around the
crossover point unless a midrange is used or the mid/woofer is 4"
diameter or less.
On the other hand:
Ring radiators don't have a resonant spike and are reasonably linear out to
around 30Khz. It's the tweeter of choice in many Sonus Faber and other high end
speaker companies.
Now, however, there is an emerging tweeter type based on a textile dome
wherein the tip of the dome is "pinned" in place. This converts the
tweeter from a traditional dome tweeter to a ring radiator. I first saw it on
Internet-Direct speaker vendor Aperion's website in their top href=http://lghttp.12393.nexcesscdn.net/805C8C/cdndirectory/media/catalog/
product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/p/r/product-
1194.jpg>Verus line, but I see where Sonus Faber has implemented a very
similar thing in their new href=http://hifilounge.co.uk/image/cache/data/sonusfaber/Olympica%20II/fea4
5bd9-7d1b-4cca-023a-0497ef7e7864-399x325.jpg>Olympica line. Such
a tweeter would be less susceptible to overshoot and beaming, and SF claims
such a tweeter can handle a lower crossover point than for the same tweeter
without the pin.
I thought this tweeter type was a clever concept when I first saw it on the
Aperion, but the Sonus Faber version sort of validates the concept for me. The
grand-bookshelf-loudspeaker-measurements>Stereophile review
measurements show the Aperion tweeter to peak by 5 dB at 10Khz, drop 5
db by 20 Khz, and then rise 5 dB again to 30 Khz, more like a Vifa ring radiator.
Similarly, Sonus Faber claims response out to 30 Khz in its Olympica line.
That said, my current favorite tweeter is the quasi-ribbon in my new
Magneplanar 1.7s. Fast, smooth, extended, good dispersion, and nary a hint of
beaming, overshoot, noticeable dips or peaks, or ringing.