Polymer Audio Research, Diamonds Are a Speakers Best Friend

October 30, 2007 by Lukas Gilkey
Filed under: Home Audio > Speakers



What does a $12,350 midrange driver with a pure diamond diaphragm look like?

Pictures after the jump.



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.



Specs:
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: Polymer Audio
Comments (7)
1883atlantics 2 years and 3 months ago

can someone shed some light on why diamonds and gold make the speakers sound better? Cubic Zirconia is harder on the Rockwell scale but not "precious" so there must be some rationale to "needing" actual diamonds...
ccdoggy 2 years and 3 months ago

because its expencive and adds bling?
lukas 2 years and 3 months ago

Check out the Bowers & Wilkins website link below for a good read on why they use diamond dome tweeters. I've heard the B&W Signature Diamond loudspeakers in person and they sound great.

Bowers & Wilkins Diamond Tweeters

Dave Kay 2 years and 3 months ago

A diamond midrange though? What's the point of that? The need for a 2.5" mid-tweeter is questionable to begin with, as most modern composite or metal based midranges are within their comfortable operating zone at the x-over point, usually around 2-4kHz. Speakers that do use large dome mid-tweeters though usually just use a metal like titanium, as the response range of a mid-tweeter is far below titanium's breakup point.

And whats the deal with gold plating drivers? Its not actually a gold tweeter like in a Monitor Audio speaker, just gold plated titanium. I dont see any point to that, other than flash.
Dave Kay 2 years and 3 months ago

Hmmm, apparently Monitor tweeters were always gold anodized aluminummagnesium, even in the old Studios. Nevermind.
1883atlantics 2 years and 3 months ago

so why a diamond anything (tweet, mid) over a different esoteric type of technology like planar drivers or such? I'm a bit of a noob when it comes to the diamond-drivers, etc.
ps. thanks for the info Lukas!
jeff
Dave Kay 2 years and 3 months ago

1883atlantics:

Just about every type of driver out there has strengths and weaknesses. Ribbons, ES panels, and Planars are better than domes at things like transient response and UHF breakup points, but they have vertical dispersion issues. A hemisphere dome has the same vertical dispersion as horizontal dispersion, where as a typical rectangular shaped ribbon's vertical dispersion is a limited window that doesn't really extend much above and below the driver itself. Some speaker builders purposefully limit the dispersion of a dome though using a waveguide, or in the case of Thiel and KEF speakers, the midrange driver.

Sometimes you see a bit of a blend between a dome and ribbon design, as in the classic Genesis circular ribbon tweeter. It can't match the frequency response of some of the larger ribbons, but it has superior dispersion.
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