Size of Midrange Drivers

Kijanki, yes larger diameter voice coils are definitely desirable from a thermal standpoint, all else being equal. Ferrofluid helps as well, assuming it's a good heat conductor, which it probably is. On the other hand I don't recall seeing any prosound company using ferrofluid, so it may have downsides when subjected to high temperatures over time.

I can't comment on the unorthodox suspension system of the cone drivers in the Hyperion; I don't know enough about suspension systems.

Duke

Kijanki: I just checked out the 6Moons in-depth review (from 10 yrs ago) of the Hyperion hps-938. The midrange unit addresses this dispersion challenge in its design. Notice that the Hyperion midrange has a large, flat dustcap. It's not a typical dustcap, however. Hyperion called this the SVF--Synchro Vibrate Flattop. This dustcap floats independent of the main diaphragm and is connected directly to the voice coil. What this does is provide a midrange-within-a-midrange of smaller diameter to ensure wider dispersion of high frequencies that would beam at 6-1/2" but not at 3" (or whatever diameter this floating dustcap is). That's a pretty ingenious solution to have it both ways--larger diameter for more radiating surface and deeper reach while keeping dispersion consistent as frequencies rise toward that rather high 3K crossover point.

That's what whizzer cones and phase plugs are used for in many fullrange drivers (e.g. Fostex and Audio Nirvana). But Hyperion's flattop dust cap strikes me as a more ingenious and precise way to achieve that.

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

Hey! Tannoy! You've only been making speakers since 1926 so take some more lessons because somebody on this web-site thinks you and I are "confused".

Stop making your $55,000 Kingdom Royal until you get straightened out and start using 5" midrange drivers!

(dang this is fun!)...

08-24-14: Dweller
Hey! Tannoy! You've only been making speakers since 1926 so take some more lessons because somebody on this web-site thinks you and I are "confused".

Stop making your $55,000 Kingdom Royal until you get straightened out and start using 5" midrange drivers!

(dang this is fun!)...

Dweller, you asked the question & when info has been given to you, you don't want to learn! There seems to be disbelief on your part. Why ask the question if you don't want to learn??? Just curious to know...

This info from 2 websites: tannoyspeakers.com & tannoy.com (it looks like you haven't spent much time reading it..)

The first Dual Concentric loudspeaker, designated the monitor black, and designed by Tannoy's chief engineer at the time, Ronnie H. Rackham, appeared at the London Radio Show in 1947.

It was in 1926 when Guy R. Fountain (GRF) perfected a new type of electric rectifier with the aim of designing a charger more suitable for use in the home.
I really don't know when Tannoy built it's 1st speaker but it wasn't in 1926.

the following info is about the Tannoy Kingdom Royal loudspeaker from Tannoy's website. Read a little about the Kingdom Royal's drive unit - scroll to the middle of that webpage & look under "Drive Unit":

The crossover to the DC’s high frequency unit occurs at an exceptionally low 700Hz to ensure the majority of the vocal region is handled by the new tweeter.

The Tannoy Kingdom Royal has NO MIDRANGE driver contrary to what you seemed to allude to.
Their new HF compression driver tweeter is doing all the midrange.
Like you seemed to indicate - Tannoy is not foolish & they wouldn't put a 12" midrange! The 12" unit does upper bass to 700Hz & the lower bass unit does the bottom-most octave.

You know, Shakey might have a very valid point.....