[srb]

So how much does the 100K tweeters cost?   (Kidding....if I have to ask, I can't afford it.    )

The RAAL Flatfoil ribbon tweeters are spec'd to 100KHz and sell for ~ $350 to $700 depending on low end frequency response (2KHz or 500Hz).

Steve

[Don_S]

Look for plasma tweeter if you want the most hi freq response in treble.

Plasma tweeters are the best I have ever heard.  Very airy and not harsh. No beaming. It is not about hearing the high frequencies.  Plasma tweeters give a great sense of spaciousness.

I wish they were not so expensive and did not have a limited lifespan.

[Pete Schumacher]

The RAAL Flatfoil ribbon tweeters are spec'd to 100KHz and sell for ~ $350 to $700 depending on low end frequency response (2KHz or 500Hz).

Steve

The RAAL ribbons are as close to a diaphragm-less tweeter as you can get before going plasma.  The mass of the air the ribbons move in their audio range actually weighs more than the ribbon itself which is a big boon for stored energy issues.  They also exhibit among the smoothest response of any tweeter, dynamic, AMT, planar or plasma.

Best of all, they sound amazing delivering a naturalness unlike any other tweeter I've heard.  Whether that's a result of their extended response is debatable of course.  It's still difficult to answer why a speaker using a soft dome with extended top end response to well beyond 20KHz (for example the Scan 6600) sounds different from the same speaker using a RAAL and EQ'd to the same response.

It's good to have choices!

[Steve]

Can anyone point to any good articles on the subject?

Wouldn't this be like saying: "My TV outputs X-rays, and even though I can't see them, it makes the picture look better" ?

1) There is a Japanese study with actual measurements via EEG and PET scans. Some groups have been intimidated by the study and
made false claims, including that headphones were used instead of super tweeters 8 feet away. Others have altered the methodology etc.
in order to discredit the measurements.

2) I believe Pete rightly discerned that phase relationsships are enhanced. No problem with "overkill".

3) At least two studies, one presented by Jneutron, and another concluded the ear, each ear, can discern 5us and 1.5us (us = microseconds) respectively.
As such each component of a system, including the speaker, determines the rise time (many audiophiles call it attack time) of the system. Increase the rise time of the speaker and the system's rise time increases.

Just off the top of my head, could be more.

Cheers

Steve

[Steve]

The RAAL ribbons are as close to a diaphragm-less tweeter as you can get before going plasma.  The mass of the air the ribbons move in their audio range actually weighs more than the ribbon itself which is a big boon for stored energy issues.  They also exhibit among the smoothest response of any tweeter, dynamic, AMT, planar or plasma.

Best of all, they sound amazing delivering a naturalness unlike any other tweeter I've heard.  Whether that's a result of their extended response is debatable of course.  It's still difficult to answer why a speaker using a soft dome with extended top end response to well beyond 20KHz (for example the Scan 6600) sounds different from the same speaker using a RAAL and EQ'd to the same response.

It's good to have choices!

Yep. Plasmatronics (thinking of Hills Plasmatronics, although "slow" woofer) and the Heils are also super sounding.

Cheers

Steve

ps. Corrected my spelling.

[*Scotty*]

Hill Plasmatronics
Scotty

[JLM]

1) There is a Japanese study with actual measurements via EEG and PET scans. Some groups have been intimidated by the study and
made false claims, including that headphones were used instead of super tweeters 8 feet away. Others have altered the methodology etc.
in order to discredit the measurements.

2) I believe Pete rightly discerned that phase relationsships are enhanced. No problem with "overkill".

3) At least two studies, one presented by Jneutron, and another concluded the ear, each ear, can discern 5us and 1.5us (us = microseconds) respectively.
As such each component of a system, including the speaker, determines the rise time (many audiophiles call it attack time) of the system. Increase the rise time of the speaker and the system's rise time increases.

Just off the top of my head, could be more.

Cheers

Steve

PET (positron emission technology) would require headphones as the scanner is combined with a C.T. scanner (large donut you fit inside of).

[Steve]

PET (positron emission technology) would require headphones as the scanner is combined with a C.T. scanner (large donut you fit inside of).

Sorry if I was not clear JL. The gent clearly stated in his post that the reproducing system included headphones on one's head, in place of super tweeters 8 feet away. If you are discussing PET scan procedure (only PET), headphones are not necessarily needed. Remember this was a study concentrating on hearing. The study was performed at a major hospital by at least 10, which includes scientists, the President of the National Institute of Radiological Sciences etc, plus technicians etc at the hospital, so quite reliable scientists. As such I don't think there is anything to worry about.

Here is the qualifications of just one of the 10+.

Dr. Yoshiharu Yonekura:

Dr. Yoshiharu Yonekura is a Member of the Science Council of Japan, Professor Emeritus at the University of Fukui and President of the National Institute of Radiological Sciences (NIRS), Chiba, Japan.

After he received an MD degree in 1973, he worked at the Kyoto University Hospital and trained in Radiology and Nuclear Medicine. He also received a PhD degree in Medical Sciences from Kyoto University in 1980, where he was later engaged as Faculty member (1980-1995) in scientific research and clinical activities in the field of Nuclear Medicine and Positron Emission Tomography (PET). In 1995, Dr. Yonekura became Professor at the Biomedical Imaging Research Center of the University of Fukui, where he conducted various research projects related to brain science and tumour diagnosis (1995-2006).

Since 2005 Dr. Yonekura has been a member of Committee 3 of the International Committee of Radiation Protection (ICRP). Within this Committee he serves as Chair of the Task Group on radiological protection in ion beam radiotherapy.
 
In Japan, Dr. Yonekura is Chair of the Radiation Protection Committee at the Nuclear Safety Commission and Sub-Chair of the Radiation Council. He received the Kuhl-Lassen lecture award from the Society of Nuclear Medicine in 2001.
Dr. Yonekura has been the Representative of Japan to UNSCEAR since 2007.

ICRP: Full ICRP Membership List
www.icrp.org, 26 Nov 2010 [cached]
Dr Yoshiharu Yonekura
National Institute of Radiological Sciences (NIRS), Japan
Member, Committee 3
Chair, Task Group 87

2008: Yoshiharu ...
www.jsnm.org, 3 April 2007 [cached]
2008: Yoshiharu Yonekura,National Institute of Radiological Sciences
...
Yoshiharu Yonekura, National Institute of Radiological Sciences;
...
Members: Kiyoko Kusakabe; Yoshiharu Yonekura; Norinari Honda; Kiyoshi Koizumi
...
Director, Chairman: Yoshiharu Yonekura
...
Members: Tamio Aburano; Kiyoko Kusakabe; Kiyoshi Koizumi; Harumi Sakahara; Fumio Shishido; Yoshiharu Yonekura

ARCCNM - Asian Regional Cooperative Council for Nuclear Medicine
www.arccnm.org, 26 Nov 2011 [cached]
Nuclear Neurology: Dr. Yoshiharu Yonekura (Japan)


:::::ARCCNM:::::
www.arccnm.org, 1 Nov 2001 [cached]
 - Nuclear Neurology: Dr. Yoshiharu Yonekura (Japan)

The ear is also sensitive to at least 5us (1.2us according to Jneutron). We are talking a very high frequency, approximately 200khz sinewave, to produce a 5us rise time (10-90% of minimum to maximum).

Cheers

Steve

[FullRangeMan]

The Gallo CDT tweeters get up around 35k which is not too shabby

Some Gallo speakers with this tweeter you mention dont has xover and are two way, which are some rare combination.

[dlaloum]

Yes but those need a sub... The full range model has a xo to the woofer but no xo between mids and CDT tweeter...