Heil Air Motion Transformer Drivers to be Available for DIY

July 21, 2008 by Lukas Gilkey
Filed under: Home Audio > DIY Raw Drivers



Mark and Daniel Loudspeakers have announced that they will be making their highly regarded DREAMS (Directly Responding Emitter by Air Motion Structure) drivers available to the public for diy. The drivers are used in their speaker line and based upon the Heil ESS Air Motion Transformer drivers. Two of the four DREAMS/ESS Heil drivers will be available in late August with prices of $180 and $250 per pair depending on the model.

John Krutke of Zaph Audio has already shown interest and it appears he will be getting some test units in the near future. Definitely looking forward to his thoughts on the drivers.

More info and specs on the two models after the jump.


Heil AMT DM-2 Supertweeter:
- Bandwidth: 1.4KHz up to 35 KHz
- 38 units of light weight micro elements
- Total moving dimension is 12X over a typical 1" dome tweeter
- Low FMD pollution and high power handling
- Higher SPL output capability than the conventional HF tweeters
- 8 units of NdFeB magnets form the magnetic loop
- Impedance: 3.5 to 6.5 Ohms depending on different versions
- Efficiency: 88dB/2.83V/1m
- Dimensions: 4" diameter x 1.1" deep
- Weight: 1.1 lbs.
- Price: $180 per pair



Heil AMT DM-4 Wideband Dreams Driver:
- Bandwidth: 750Hz up to 25KHz
- 32 units of light weight micro elements
- Total moving dimension is 30X over a typical 1" dome tweeter
- Low FMD pollution and high power handling
- Higher SPL output capability than the conventional HF tweeters
- 14 units of NdFeB magnets form the magnetic loop
- Recommended crossover: between 750Hz to 1.5KHz
- Impedance: 4 to 6.5 Ohms depending on different versions
- Efficiency: 88dB/2.83V/1m
- Dimensions: (H) 122mm x (W) 88mm x (D) 27mm
- Weight: 1.7 lbs.
- Price: $250 per pair

Source: Mark and Daniel of America
Source: Tech Talk
Comments (7)
lukas 4 months and 1 day ago

I'm a huge fan of their speakers, so definitely looking forward to seeing the diy projects people create with these.
ccdoggy 4 months and 1 day ago

Wow, that is impressive, what are they? modified ribbon or something magical?
lukas 4 months and 1 day ago

"The diaphragm pushes back and forward from itself in a similar physical motion pattern to what is observed when an accordion is squeezed in and out to pump air though the reed chambers, albeit over an exceedingly smaller motion range.

The result is a dipole driver with an extraordinarily rapid response rate, caused both by the extremely low mass of the polyester driver, and by the far smaller motion range it undergoes on each "swing" compared to a dynamic driver. In this technical respect, it shares characteristics with the electrostatic driver.

The discernible motion of each of these diaphragm flexes is very small, but because of the folded structure more air is moved than would be by a conventional cone or electrostatic driver of the same plotted surface area. As a matter of surface comparison, a standard one-inch-wide AMT strip has a functional driver area which is comparable to a circle-shaped dynamic cone with a diameter of eight inches. The folded driver design, combined with the small motive range, means that the AMT acts like a point source version of a larger driver, inherently resulting in lower distortion in sound reproduction. As a result of its motion pattern, the AMT "spits" the air out in a way which is compatible with what happens when, although you apply only a small amount of pressure to a slice of fruit, the pip inside shoots out at high speed. The motion of the air as it leaves the diaphragm is in fact around five times faster than the motion of the actual driver structure. Hence the name Air Motion Transformer."

Wikipedia Link
ngsm13 4 months and 1 day ago

Hmm...

Should I put a pair in my truck?
lukas 4 months and 1 day ago

Funny you mention that, there was a guy on the Parts Express forum that mentioned he had been using previous versions in all of his vehicles.
ngsm13 4 months and 1 day ago

Well, are they severely directional? What's the off-axis response and dispersion like on them?

Hmmm... I'm really in search of a high output "tweeter" with decent extension below 2kHz...
lukas 4 months and 1 day ago

You may have to wait for John Krutke's measurements to get a better idea of the true off-axis response.
Please Login or Register to comment on this story.