Size of Midrange Drivers

6.5" midrange drivers in my Hyperion HPS-938 speakers
cover range of 230-3000Hz. They have ferrofluid suspension
instead of traditional "spiderweb". Here is what
hyperion says about it:

"The Magnetic Fluid Damping System (M.F.D.S.) is
another innovative design for our revolutionary speaker
drivers. The S.V.F. driver does not have a spider, which is
an essential part of conventional speaker drivers for
holding and stabilizing the sound coil. Although the spider
is important for conventional speakers, it is also
considered as a source of vibration and sound coloration.
Our M.F.D.S replaces the spider completely, increases the
driver speed dramatically, and enables the purity of sound
reproduction."

[url]http://www.hyperionsound.com/HPS-938.htm[/url]

These relatively inexpensive speakers have one of the best
midrange I've ever heard. Unfortunately company went
bankrupt in spite of very good product (poor marketing, poor
dealer base).

Johnyb53, I cannot hear that. Perhaps others couldn't hear it either since it received whole bunch of awards including Absolute Sound "Speaker of the Year" 5 years in a row, Enjoy the Music "Best of 2004" and "Decade Award", Stereo Times 2005, 2006 award, Blue Moon award and many glowing reviews like this one: http://hyperionsound.com/Images/Hear%20the%20Hype_low_res.pdf

Perhaps one shouldn't judge speaker sound by one calculation?

Duke, midrange drivers in my speakers use ferrofluid suspension instead of spiderweb (to increase speed by lowering overall mass). Coils are oversized connected to flat ring that holds membrane (instead of dust cap).

http://www.enjoythemusic.com/superioraudio/equipment/1104/hyperionhps938.htm

I assume that oversized coil in ferrofluid has low thermal compression. I'm only worrying that ferrofluid will dry out one day.

Lewinskih01, I have no idea. Hyperion went bankrupt (poor marketing,
poor dealer base) without any parts sale. I'm not sure why they decided
upon such large midrange driver but I suspect they wanted to reduce
membrane excursion making it more linear. 3kHz xover was probably
selected to stay away from the tweeter's resonance that is around 1.5kHz.
If this xover is single pole 6dB per octave then tweeter helps keeping
dispersion around 2.5-3kHz, as Johnyb53 stated. It is possible to
improve linearity at large excursions by using underhung, instead of
common overhang motor. It is rare, likely because of the increased cost
(large magnet). I've seen this only in Acoustic Zen woofers or Morel
Supreme tweeters. In underhung motor coil is very narrow while
magnetic gap is very wide. Coil is all the time inside opposite to
overhang design where coil is long being mostly outside of very narrow
magnetic gap.

Johnyb53, unfortunately Hyperion went bankrupt since design is only small part of success. Now, I feel uneasy about spare parts or service.