ESS Heil AMT (Air Motion Transformer) Tweeter Pair - Original!

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General:
These are original vintage units, not current reproductions as you'll likely find on the internet.

Perfect for getting a bit more sparkle out of your vintage speakers, or for your next dream build.

"Invented by the noted physicist and scientist, Dr. Oskar Heil, the ESS Heil Air Motion Transformer (AMT) tweeter uses a folded pleated Mylar diaphragm just 0.0005" thick. Its voice coil is a serpentine pattern of precision-etched aluminum, selected for minimal weight and high power handling.

Unlike a normal piston loudspeaker that excites the air by alternately pushing and pulling a cone or dome, the Heil AMT Air Motion Transformer linearly squeezes and expands its diaphragm's pleats, moving the airload at a very high velocity.

Because the moving mass of the Air Motion Transformer is extremely low and the magnetic structure very powerful, this combination results in extremely high acceleration that yields amazing transients."

Ownership:
Single Owner

Cosmetic Condition:
7/10 = Good. One or two minor scratches. Well Maintained.. See our detailed rating description here.

Working Condition:
Working perfectly and tested in our lab and listening room.

Included:
Exactly as pictured and described above.

Packing:
Will be packed using our highly developed in-house process and custom packing materials.Specs:
Impedance:
4 ohms, Re: 2.9 ohms

Power: 
40 watts RMS, 160 watts max

Response:
800 Hz - 20 kHz

Sensitivity:
92 dB, 1 watt, 1 meter

Dimensions:
Height: 6"
Width: 6.75"
Depth: 4.25"

Weight:
14.5 lbs.

Recommended Cables:

Kimber Kable - Speaker Cables - Better

Kimber Summit Series Monocle XL Speaker Cables (PAIR) - Best

Kimber Summit Series BiFocal XL Bi-Wire Speaker Cables (PAIR) - Best if Applicable

Testing Process:

Our speaker evaluation process starts with a visual inspection of all drivers. We are looking for damaged or deteriorating woofer surrounds, dented tweeter domes, and cone damage. We also inspect the speaker connection points for loose or broken connectors.

After the initial visual inspection we connect the speakers to a reference amplifier with our preferred test tracks. With the speakers placed with proper distance we listen to each driver to make sure that they are producing the intended frequencies with no signs of distortion or rattle. During listening tests with test tracks we check for proper stereo imaging and bass response at various listening levels. If there are any audible signs of issues, the speakers are taken to the bench where we perform a frequency sweep to isolate the issue so that it can be resolved by component repair or replacement.

Our subwoofer evaluation process starts with a visual inspection of all drivers. We are looking for damaged or deteriorating woofer surrounds, cone damage, or rubbing voice coils. We also inspect the input connections for damage.

After the initial visual inspection, we connect the sub at our bench and perform a sine wave sweep from about 200Hz down to around 10Hz. During this sweep we are listening for excessive rattle or other signs of improper function. If the sweep passes, we then increase the input level to evaluate how the woofer performs at high output levels. If the woofer has built in crossover features or multiple connection options these features are tested at this time.

We complete the subwoofer evaluation by feeding the unit with an audio signal in conjunction with our house music system to see how it responds to low frequency content in real world conditions while paired with a full range system.