The Polymer Audio Research Polymer Logic Loudspeakers use one of the diamond cone midrange drivers (pictured above) per side in addition to a Supravox TG1 tweeter and a pair of hand made vapor deposited titanium cone woofers.
Polymer Research states that, "The diamond midrange cone in the Polymer Logic currently exists in only one commercially available loudspeaker system, the $250,000/pr Marten Design Coltrane Supreme." And don’t think for a second that tweeter has gold paint on it, that is a titanium dome covered in a pure layer of solid gold.
"The Polymer Logic is clearly an astonishing value for $24,990/pr and contains more pure diamond and gold then you’ll find in any $500,000 diamond engagement ring."
The only thing missing from these speakers is a Leprechaun to guard the treasure.
According to Polymer Research the diamond midrange drivers are made one at a time in a plasma reactor and because of cones that often crack in the process, it usually takes about 6 weeks to make a pair of the drivers.
Specifications
Nominal impedance: 5 ohms (minimum impedance 4.1 ohms)
Woofer: Two 7" vapor deposited titanium
Midrange: One 2.5" diamond cone
Tweeter: One 1" gold coated titanium dome
Sensitivity: 91dB @ 1 watt (2.0V at 1 meter)
Minimum amplifier power: 12 WPC
Frequency response: 30Hz – 40kHz
System weight: 285 lbs each tower
Approximate shipping weight: 820 lbs for complete system
Height: 48.75” (including supplied supports)
Width: 13”
Depth: 15”
Price: $24,990/pr
Source: http://polymeraudio.com